1
|
Thunell E, Peter M, Iravani B, Porada DK, Prenner K, Darki F, Lundström JN. Unisensory visual and auditory objects are processed in olfactory cortex, independently of odor association. Cortex 2025; 186:74-85. [PMID: 40250310 DOI: 10.1016/j.cortex.2025.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2024] [Revised: 04/04/2025] [Accepted: 04/04/2025] [Indexed: 04/20/2025]
Abstract
Primary sensory cortices have been demonstrated to process sensory input from non-preferred sensory modalities, e.g., primary visual cortex reacting to auditory stimulation, bringing their presumed sensory specificity into question. Whether this reflects processing of the non-preferred stimulus per se or originates from cross-modal associations is debated. Visual/auditory objects typically have strong reciprocal associations; hence, it is difficult to address this question in these modalities. Here, we dissociate between the two competing hypotheses of whether this form of activation in primary cortices is caused by unisensory processing or cross-modal associations by turning to the olfactory system where cross-modal associations are generally weaker. Using unisensory visual and auditory objects with odor associations ranging from none to strong, we show that the posterior piriform cortex, an area known to process odor objects, is activated by both sounds and pictures of objects. Critically, this activation is independent of the objects' odor associations, thereby demonstrating that the activity is not due to cross-modal associations. Using a Floyd-Warshall algorithm, we further show that the amygdala mediate condition-relevant information between the posterior piriform cortex and both the auditory and visual object-oriented cortices. Importantly, we replicate past findings of clear crossmodal processing in the visual and auditory systems. Our study demonstrates processing of non-olfactory input in olfactory cortices that is independent of cross-modal associations and contributes to a more nuanced view of modality specificity in olfactory, auditory, and visual cortices.
Collapse
Affiliation(s)
- Evelina Thunell
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Psychological Sciences, Purdue University, West Lafayette, IN, USA.
| | - Moa Peter
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Behzad Iravani
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neurology and Neurological Sciences, Stanford University, CA, USA.
| | - Danja K Porada
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Katharina Prenner
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Fahimeh Darki
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
| | - Johan N Lundström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Monell Chemical Senses Center, Philadelphia, PA, USA; Stockholm University Brain Imaging Centre, Stockholm University, Stockholm, Sweden.
| |
Collapse
|
2
|
Okumura T, Saito K, Harada R, Ohki T, Hanihara H, Kida I. Latent preference representation in the human brain for scented products: Effects of novelty and familiarity. Neuroimage 2025; 310:121131. [PMID: 40058534 DOI: 10.1016/j.neuroimage.2025.121131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2024] [Revised: 03/03/2025] [Accepted: 03/06/2025] [Indexed: 03/20/2025] Open
Abstract
Decoding latent preferences for novel products is crucial for understanding decision-making processes, especially when subjective evaluations are unclear. Brain activity in regions like the medial orbitofrontal cortex and nucleus accumbens (NAcc) correlates with subjective preferences. However, whether these regions represent preferences toward novel products and whether coding persists after familiarity remain unclear. We examined the brain coding of latent preferences for novel scented products and how they evolve with familiarity. We measured functional magnetic resonance imaging (fMRI) signals evoked by three fabric softener odors, both when novel and when familiar, in 25 previously unexposed females. To obtain reliable preferences, participants chose one softener after using all three twice at home after the first fMRI measurement (Day 1) and continued using it at home for four months until the second day of the fMRI measurement (Day 2). Subjective ratings were also obtained after each fMRI run. On Day 1, no significant differences in subjective ratings between selected and non-selected odors were found. However, the decoding analysis revealed that future odor preferences for novel products were coded in several regions, including the left superior frontal lobe (SF), right NAcc, and left piriform cortex. On Day 2, the left SF continued to encode preferences after familiarity. These results suggest that odor preferences for novel products are coded in the brain even without conscious awareness, and that the coding in the SF is robust against familiarity. These findings provide insights into a more comprehensive understanding of the brain coding of latent preferences.
Collapse
Affiliation(s)
- Toshiki Okumura
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Osaka, Japan, 1-4 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan
| | - Kai Saito
- Research and Development Headquarters, LION Corporation, Tokyo, Japan, 1-3-28 Kuramae, Taitou-ku, Tokyo, 111-8644, Japan
| | - Risako Harada
- Research and Development Headquarters, LION Corporation, Tokyo, Japan, 1-3-28 Kuramae, Taitou-ku, Tokyo, 111-8644, Japan
| | - Tohru Ohki
- Research and Development Headquarters, LION Corporation, Tokyo, Japan, 1-3-28 Kuramae, Taitou-ku, Tokyo, 111-8644, Japan
| | - Hiroyuki Hanihara
- Research and Development Headquarters, LION Corporation, Tokyo, Japan, 1-3-28 Kuramae, Taitou-ku, Tokyo, 111-8644, Japan
| | - Ikuhiro Kida
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT), Osaka, Japan, 1-4 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan.
| |
Collapse
|
3
|
Dorian CC, Taxidis J, Buonomano D, Golshani P. Hippocampal sequences represent working memory and implicit timing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.17.643736. [PMID: 40166270 PMCID: PMC11956965 DOI: 10.1101/2025.03.17.643736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/02/2025]
Abstract
Working memory (WM) and timing are considered distinct cognitive functions, yet the neural signatures underlying both can be similar. To address the hypothesis that WM and timing may be multiplexed we developed a novel rodent task where 1st odor identity predicts the delay duration. We found that WM performance decreased when delay expectations were violated. Performance was worse for unexpected long delays than for unexpected short delays, suggesting that WM may be tuned to expire in a delay-dependent manner. Calcium imaging of dorsal CA1 neurons revealed odor-specific sequential activity tiling the short and long delays. Neural sequence structure also reflected expectation of the timing of the 2nd odor-i.e., of the expected delay. Consistent with the hypothesis that WM and timing may be multiplexed, our findings suggest that neural sequences in dorsal CA1 may encode cues and cue-specific elapsed time during the delay period of a WM task.
Collapse
Affiliation(s)
- Conor C. Dorian
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Jiannis Taxidis
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Dean Buonomano
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Greater Los Angeles Veteran Affairs Medical Center, Los Angeles, CA, USA
- Intellectual and Developmental Disabilities Research Center, University of California Los Angeles, Los Angeles, CA, USA
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
- Integrative Center for Learning and Memory, University of California, Los Angeles, CA, USA
| |
Collapse
|
4
|
Shanahan LK, Mithal LB, Messina M, Office E, Wakschlag L, Seed P, Kahnt T. Characterizing Olfactory Brain Responses in Young Infants. J Neurosci 2025; 45:e1780242025. [PMID: 39870525 PMCID: PMC11905341 DOI: 10.1523/jneurosci.1780-24.2025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2024] [Revised: 12/10/2024] [Accepted: 01/08/2025] [Indexed: 01/29/2025] Open
Abstract
Odor perception plays a critical role in early human development, but the underlying neural mechanisms are not fully understood. To investigate these, we presented appetitive and aversive odors to infants of both sexes at 1 month of age while recording functional magnetic resonance imaging (fMRI) and nasal airflow data. Infants slept during odor presentation to allow MRI scanning. We found that odors evoke robust fMRI activity in the bilateral olfactory cortex and thalamus and that fMRI response magnitudes in the olfactory cortex differ across odors. However, in contrast to prior work in adults, we did not find compelling evidence that odor stimuli evoke discriminable fMRI activity patterns in the olfactory cortex or thalamus using two different multivariate pattern analysis techniques. Finally, the average inhale airflow rate was higher for appetitive odors than aversive odors, which tentatively suggests that infants could modulate their respiration to reflect odor valence. Overall, these results show strong neural responses to odors at this early developmental stage and highlight nasal airflow as a behavioral metric for assessing odor preference in infants.
Collapse
Affiliation(s)
- Laura K Shanahan
- Department of Psychology, Rhodes College, Memphis, Tennessee 38112
- Departments of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - Leena B Mithal
- Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
- Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois 60611
| | - Marci Messina
- Northwestern Memorial Hospital, Chicago, Illinois 60611
| | - Emma Office
- Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - Lauren Wakschlag
- Department of Medical Social Sciences, Feinberg School of Medicine and Institute for Innovations in Developmental Sciences, Northwestern University, Chicago, Illinois 60611
| | - Patrick Seed
- Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
- Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois 60611
| | - Thorsten Kahnt
- Departments of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
- National Institute on Drug Abuse Intramural Research Program, Baltimore, Maryland 21224
| |
Collapse
|
5
|
Zahnert F, Reichert P, Linka L, Timmermann L, Kemmling A, Grote A, Nimsky C, Menzler K, Belke M, Knake S. Relationship of left piriform cortex network centrality with temporal lobe epilepsy duration and drug resistance. Eur J Neurol 2025; 32:e70018. [PMID: 39949073 PMCID: PMC11825592 DOI: 10.1111/ene.70018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Accepted: 12/10/2024] [Indexed: 02/17/2025]
Abstract
BACKGROUND We investigated the relationship of piriform cortex (PC) structural network centrality with drug resistance and epilepsy duration as markers of sustained epileptic activity. METHODS PCs were manually delineated on retrospectively collected 3D-T1-MRI images of patients with temporal lobe epilepsy (TLE). Connectomes were computed from diffusion MRI scans, including the PC as network nodes. Betweenness centrality (BC) and node degree were computed and compared across drug-resistant versus drug-sensitive patients. Correlations of centrality metrics with the duration of epilepsy were calculated. RESULTS Sixty-two patients (36 females, 43/62 drug-resistant) were included in the main analysis. Greater centrality of the left PC was associated with drug resistance (degree: p = 0.00696, d = 0.85; BC: p = 0.00859, d = 0.59; alpha = 0.0125). Furthermore, left PC centrality was correlated with epilepsy duration (degree: rho = 0.39, p = 0.00181; BC: rho = 0.35, p = 0.0047; alpha = 0.0125). Results were robust to analysis of different parcellation schemes. Exploratory whole-network analysis yielded the largest effects in the left PC. Finer parcellations showed stronger effects for both analyses in the left olfactory cortex rostral to PC. In 28 subjects who had received epilepsy surgery, a trend of smaller centrality in patients with ILAE I outcome was observed in this area. CONCLUSIONS We demonstrated an increased centrality of the left PC in patients with drug-resistant TLE, which was also associated with the epilepsy duration. Recurring seizures over long periods may lead to changes of network properties of the PC. Large effects immediately rostral to our delineated PC region suggest a role of olfactory cortex anterior to the limen insulae in epileptogenic networks.
Collapse
Affiliation(s)
- Felix Zahnert
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Paul Reichert
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Louise Linka
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Lars Timmermann
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - André Kemmling
- Department for NeuroradiologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Alexander Grote
- Department for NeurosurgeryUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Christopher Nimsky
- Department for NeurosurgeryUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
- Center for Mind, Brain and Behavior (CMBB)Philipps‐University MarburgMarburgGermany
| | - Katja Menzler
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
- Center for Mind, Brain and Behavior (CMBB)Philipps‐University MarburgMarburgGermany
| | - Marcus Belke
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
- LOEWE Center for Personalized Translational Epilepsy Research (Cepter)Goethe‐University FrankfurtFrankfurtGermany
| | - Susanne Knake
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
- Center for Mind, Brain and Behavior (CMBB)Philipps‐University MarburgMarburgGermany
- LOEWE Center for Personalized Translational Epilepsy Research (Cepter)Goethe‐University FrankfurtFrankfurtGermany
- Core Facility Brainimaging, Faculty of MedicineUniversity of MarburgMarburgGermany
| |
Collapse
|
6
|
Pirc M, Krale C, Smeets P, Boesveldt S. Perceptual differences in olfactory fat discrimination are not detected in neural activation. Chem Senses 2025; 50:bjaf007. [PMID: 39964953 PMCID: PMC11931621 DOI: 10.1093/chemse/bjaf007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2024] [Indexed: 02/20/2025] Open
Abstract
Olfaction is involved in detecting, identifying, and discriminating dietary fat within foods, yet the underlying neural mechanisms remain uncharted. Our functional magnetic resonance imaging (fMRI) study investigated the neural correlates of olfactory fat perception and their association with discrimination ability in a complex food matrix. We measured brain activation resulting from orthonasal exposure to an ecologically relevant fat-related odor source-dairy milk, manipulated to contain 0%, 3.5%, or 14% fat. Twenty-six healthy, normosmic adults underwent olfactory fat content discrimination testing, followed by an fMRI task during which the 3 odor stimuli were delivered via an olfactometer (25 times/fat level) and rated on perceived intensity and liking. Participants discriminated between all fat levels, with fat level influencing perceived odor intensity and liking. These perceptual differences, however, were not reflected in differential brain activation. Brain activation differences were observed only when comparing odor exposure with no exposure. Specifically, in response to any odor, activation occurred in the anterior part of the supplementary motor area (SMA) while deactivating parts of the hippocampus, putamen, superior temporal gyrus, anterior cingulate cortex, insula, and posterior part of the SMA. Exposure to the 0% fat odor also activated the thalamus. No associations were found between perceived intensity and liking and neural responses. Results reaffirm the human ability to distinguish food fat content using solely olfactory cues and reveal a divergence between sensory perception and neural processing. Subsequent research should replicate and extend these findings onto retronasal fat perception while also examining potential effects of hunger, genetics, and dietary habits.
Collapse
Affiliation(s)
- Matjaž Pirc
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Catoo Krale
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Paul Smeets
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| | - Sanne Boesveldt
- Division of Human Nutrition and Health, Wageningen University, Wageningen, The Netherlands
| |
Collapse
|
7
|
Rezaeyan A, Asadi S, Kamrava SK, Zare-Sadeghi A. Olfactory training affects the correlation between brain structure and functional connectivity. Neuroradiol J 2024:19714009241303129. [PMID: 39626165 PMCID: PMC11615909 DOI: 10.1177/19714009241303129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Revised: 08/28/2024] [Accepted: 09/01/2024] [Indexed: 12/06/2024] Open
Abstract
PURPOSE and background: Neuroimaging studies have increasingly found functional connectivity (FC) changes and structural cortical abnormalities in patients with post-traumatic anosmia (PTA). Training and repeated exposure to odorants lead to enhanced olfactory capability. This study is conducted to investigate the correlations between FC and cortical thickness on the olfaction-related regions of the brain in PTA after olfactory training (OT). METHODS Twenty-five PTA patients were randomly divided in three groups: (1) 9 control patients who did not receive any training, (2) 9 patients underwent classical OT by 4 fixed odors, and (3) 7 patients underwent modified OT coming across 4 sets of 4 different odors sequentially. Before and after the training period, all patients performed olfactory function tests, and magnetic resonance imaging (MRI). Sniffin' Sticks test was used to assess olfactory function. MRI data were analyzed using functional connectivity analysis and brain morphometry. RESULTS Modified OT resulted in heightened activation in the medial orbitofrontal cortex and anterior cingulate cortex and increased FC between the piriform cortex (PIRC) and the caudate cortex. Conversely, classical OT induced increased activation in the insula cortex and greater FC between the PIRC and the pre-central gyrus. Furthermore, after OT, both training groups achieved significantly improved scores in the changes in brain connectivity associated with OT, which were attributable to anatomical measures. CONCLUSIONS This study demonstrates that intensive olfactory training can enhance functional connectivity, and this improvement correlates with structural changes in the brain's olfactory processing areas.
Collapse
Affiliation(s)
- Abolhasan Rezaeyan
- Department of Radiology, School of Paramedical Sciences, Gerash University of Medical Sciences, Gerash, Iran
| | - Somayeh Asadi
- Finetech in Medicine Research Center, Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Seyed Kamran Kamrava
- ENT Research Center, Institute of Five Senses, Hazrat Rasoul Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Arash Zare-Sadeghi
- Finetech in Medicine Research Center, Medical Physics Department, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
8
|
Schmidt M, Bauer T, Kehl M, Minarik A, Walger L, Schultz J, Otte M, Trautner P, Hoppe C, Baumgartner T, Specht‐Riemenschneider L, Mormann F, Radbruch A, Surges R, Rüber T. Olfactory Dysfunction and Limbic Hypoactivation in Temporal Lobe Epilepsy. Hum Brain Mapp 2024; 45:e70061. [PMID: 39487626 PMCID: PMC11530705 DOI: 10.1002/hbm.70061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Revised: 09/26/2024] [Accepted: 10/14/2024] [Indexed: 11/04/2024] Open
Abstract
The epileptogenic network in temporal lobe epilepsy (TLE) contains structures of the primary and secondary olfactory cortex such as the piriform and entorhinal cortex, the amygdala, and the hippocampus. Olfactory auras and olfactory dysfunction are relevant symptoms of TLE. This study aims to characterize olfactory function in TLE using olfactory testing and olfactory functional magnetic resonance imaging (fMRI). We prospectively enrolled 20 individuals with unilateral TLE (age 45 ± 20 years [mean ± SD], 65% female, 90% right-handed) and 20 healthy individuals (age 33 ± 15 years [mean ± SD], 35% female, 90% right-handed). In the TLE group, the presumed seizure onset zone was left-sided in 75%; in 45% of the individuals with TLE limbic encephalitis was the presumed etiology; and 15% of the individuals with TLE reported olfactory auras. Olfactory function was assessed with a Screening Sniffin' Sticks Test (Burkhart, Wedel, Germany) during a pre-assessment. During a pre-testing, all individuals were asked to rate the intensity, valence, familiarity, and associated memory of five different odors (eugenol, vanillin, phenethyl alcohol, decanoic acid, valeric acid) and a control solution. During the fMRI experiment, all individuals repeatedly smelled eugenol (positively valenced odor), valeric acid (negatively valenced odor), and the control solution and were asked to rate odor intensity on a five-point Likert scale. We acquired functional EPI sequences and structural images (T1, T2, FLAIR). Compared to healthy individuals, individuals with TLE rated the presented odors as more neutral (two-sided Mann-Whitney U tests, FDR-p < 0.05) and less familiar (two-sided Mann-Whitney U tests, FDR-p < 0.05). fMRI data analysis revealed a reduced response contrast in secondary olfactory areas (e.g., hippocampus) connected to the limbic system when comparing eugenol and valeric acid in individuals with TLE when compared with healthy individuals. However, no lateralization effect was obtained when calculating a lateralization index by the number of activated voxels in the olfactory system (two-sided Mann-Whitney U test; U = 176.0; p = 0.525). TLE is characterized by olfactory dysfunction and associated with hypoactivation of secondary olfactory structures connected to the limbic system. These findings contribute to our understanding of the pathophysiology of TLE. This study was preregistered on OSF Registries (www.osf.io).
Collapse
Affiliation(s)
- Markus Schmidt
- Department of NeuroradiologyUniversity Hospital BonnBonnGermany
- Department of EpileptologyUniversity Hospital BonnBonnGermany
| | - Tobias Bauer
- Department of NeuroradiologyUniversity Hospital BonnBonnGermany
- Department of EpileptologyUniversity Hospital BonnBonnGermany
- German Center for Neurodegenerative Diseases (DZNE)BonnGermany
| | - Marcel Kehl
- Department of EpileptologyUniversity Hospital BonnBonnGermany
| | - Anna Minarik
- Department of EpileptologyUniversity Hospital BonnBonnGermany
- Department of Medical Neuroscience, Faculty of MedicineDalhousie UniversityHalifaxNova ScotiaCanada
| | - Lennart Walger
- Department of NeuroradiologyUniversity Hospital BonnBonnGermany
- Department of EpileptologyUniversity Hospital BonnBonnGermany
| | - Johannes Schultz
- Institute of Experimental Epileptology and Cognition ResearchUniversity of BonnBonnGermany
- Center for Economics and NeuroscienceUniversity of BonnBonnGermany
| | - Martin S. Otte
- Department of Otorhinolaryngology, Head and Neck Surgery, Medical FacultyUniversity of CologneCologneGermany
| | - Peter Trautner
- Institute of Experimental Epileptology and Cognition ResearchUniversity of BonnBonnGermany
| | - Christian Hoppe
- Department of EpileptologyUniversity Hospital BonnBonnGermany
| | | | | | - Florian Mormann
- Department of EpileptologyUniversity Hospital BonnBonnGermany
| | - Alexander Radbruch
- Department of NeuroradiologyUniversity Hospital BonnBonnGermany
- German Center for Neurodegenerative Diseases (DZNE)BonnGermany
- Center for Medical Data Usability and TranslationUniversity of BonnBonnGermany
| | - Rainer Surges
- Department of EpileptologyUniversity Hospital BonnBonnGermany
| | - Theodor Rüber
- Department of NeuroradiologyUniversity Hospital BonnBonnGermany
- Department of EpileptologyUniversity Hospital BonnBonnGermany
- German Center for Neurodegenerative Diseases (DZNE)BonnGermany
- Center for Medical Data Usability and TranslationUniversity of BonnBonnGermany
| |
Collapse
|
9
|
Kim K, Bae J, Lee J, Moon SA, Lee SH, Kang WS, Moon C. The Impact of Odor Category Similarity on Multimedia Experience. Exp Neurobiol 2024; 33:238-250. [PMID: 39568180 PMCID: PMC11581825 DOI: 10.5607/en24020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2024] [Revised: 10/27/2024] [Accepted: 11/14/2024] [Indexed: 11/22/2024] Open
Abstract
Although we have multiple senses, multimedia mainly targets vision and olfaction. To expand the senses impacted by multimedia, olfactory stimulation has been used to enhance the sense of reality. Odors are primarily matched with objects in scenes. However, it is impractical to select all odors that match all objects in a scene and offer them to viewers. As an alternative, offering a single odor in a category as representative of other odors belonging to that category has been suggested. However, it is unclear whether viewers' responses to videos with multiple odors (e.g., rose, lavender, and lily) from a category (e.g., flowers) are comparable. Therefore, we studied whether odors belonging to a given category could be similar in behavioral congruency and in the five frequency bands (delta, theta, alpha, beta, and gamma) of electroencephalogram (EEG) data collected while viewers watched videos. We conducted questionnaires and EEG experiments to understand the effects of similar odors belonging to categories. Our results showed that similar odors in a specific odor category were more congruent with videos than those in different odor categories. In our EEG data, the delta and theta bands were mainly clustered when odors were offered to viewers in similar categories. The theta band is known to be primarily related to the neural signals of odor information. Our studies showed that choosing odors based on odor categories in multimedia can be feasible.
Collapse
Affiliation(s)
- Kwangsu Kim
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Smell and Taste Clinic, Department of Otorhinolaryngology, Technische Universität Dresden, Dresden 01307, Germany
| | - Jisub Bae
- Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 34126, Korea
| | - JeeWon Lee
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Sun Ae Moon
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Sang-Ho Lee
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Division of Intelligent Robot, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Won-Seok Kang
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Division of Intelligent Robot, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| | - Cheil Moon
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea
| |
Collapse
|
10
|
Kehl MS, Mackay S, Ohla K, Schneider M, Borger V, Surges R, Spehr M, Mormann F. Single-neuron representations of odours in the human brain. Nature 2024; 634:626-634. [PMID: 39385026 PMCID: PMC11485236 DOI: 10.1038/s41586-024-08016-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 09/04/2024] [Indexed: 10/11/2024]
Abstract
Olfaction is a fundamental sensory modality that guides animal and human behaviour1,2. However, the underlying neural processes of human olfaction are still poorly understood at the fundamental-that is, the single-neuron-level. Here we report recordings of single-neuron activity in the piriform cortex and medial temporal lobe in awake humans performing an odour rating and identification task. We identified odour-modulated neurons within the piriform cortex, amygdala, entorhinal cortex and hippocampus. In each of these regions, neuronal firing accurately encodes odour identity. Notably, repeated odour presentations reduce response firing rates, demonstrating central repetition suppression and habituation. Different medial temporal lobe regions have distinct roles in odour processing, with amygdala neurons encoding subjective odour valence, and hippocampal neurons predicting behavioural odour identification performance. Whereas piriform neurons preferably encode chemical odour identity, hippocampal activity reflects subjective odour perception. Critically, we identify that piriform cortex neurons reliably encode odour-related images, supporting a multimodal role of the human piriform cortex. We also observe marked cross-modal coding of both odours and images, especially in the amygdala and piriform cortex. Moreover, we identify neurons that respond to semantically coherent odour and image information, demonstrating conceptual coding schemes in olfaction. Our results bridge the long-standing gap between animal models and non-invasive human studies and advance our understanding of odour processing in the human brain by identifying neuronal odour-coding principles, regional functional differences and cross-modal integration.
Collapse
Affiliation(s)
- Marcel S Kehl
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Sina Mackay
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Kathrin Ohla
- Science & Research, dsm-firmenich, Satigny, Switzerland
| | | | - Valeri Borger
- Department of Neurosurgery, University Hospital Bonn, Bonn, Germany
| | - Rainer Surges
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
| | - Marc Spehr
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Aachen, Germany.
| | - Florian Mormann
- Department of Epileptology, University Hospital Bonn, Bonn, Germany.
| |
Collapse
|
11
|
Zahnert F, Kleinholdermann U, Belke M, Keil B, Menzler K, Pedrosa DJ, Timmermann L, Kircher T, Nenadić I, Knake S. The connectivity-based architecture of the human piriform cortex. Neuroimage 2024; 297:120747. [PMID: 39033790 DOI: 10.1016/j.neuroimage.2024.120747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 07/16/2024] [Accepted: 07/18/2024] [Indexed: 07/23/2024] Open
Abstract
The anatomy of the human piriform cortex (PC) is poorly understood. We used a bimodal connectivity-based-parcellation approach to investigate subregions of the PC and its connectional differentiation from the amygdala. One hundred (55 % female) genetically unrelated subjects from the Human Connectome Project were included. A region of interest (ROI) was delineated bilaterally covering PC and amygdala, and functional and structural connectivity of this ROI with the whole gray matter was computed. Spectral clustering was performed to obtain bilateral parcellations at granularities of k = 2-10 clusters and combined bimodal parcellations were computed. Validity of parcellations was assessed via their mean individual-to-group similarity per adjusted rand index (ARI). Individual-to-group similarity was higher than chance in both modalities and in all clustering solutions. The amygdala was clearly distinguished from PC in structural parcellations, and olfactory amygdala was connectionally more similar to amygdala than to PC. At higher granularities, an anterior and ventrotemporal and a posterior frontal cluster emerged within PC, as well as an additional temporal cluster at their boundary. Functional parcellations also showed a frontal piriform cluster, and similar temporal clusters were observed with less consistency. Results from bimodal parcellations were similar to the structural parcellations. Consistent results were obtained in a validation cohort. Distinction of the human PC from the amygdala, including its olfactory subregions, is possible based on its structural connectivity alone. The canonical fronto-temporal boundary within PC was reproduced in both modalities and with consistency. All obtained parcellations are freely available.
Collapse
Affiliation(s)
- F Zahnert
- Epilepsy Center Hesse, Department of Neurology, University Hospital Marburg, Philipps-University Marburg, Germany.
| | - U Kleinholdermann
- Department of Neurology, University Hospital Marburg, Philipps University Marburg, Germany; Department of Psychiatry and Psychotherapy, University Hospital Marburg, Philipps University Marburg, Germany
| | - M Belke
- Epilepsy Center Hesse, Department of Neurology, University Hospital Marburg, Philipps-University Marburg, Germany; Center for Personalized Translational Epilepsy Research, Goethe University Frankfurt, Germany
| | - B Keil
- Institute of Medical Physics and Radiation Protection, Mittelhessen University of Applied Sciences, Giessen, Germany; Department of Diagnostic and Interventional Radiology, University Hospital Marburg, Philipps University of Marburg, Marburg, Germany; Center for Mind, Brain and Behavior, Philipps University Marburg, Germany
| | - K Menzler
- Epilepsy Center Hesse, Department of Neurology, University Hospital Marburg, Philipps-University Marburg, Germany; Center for Mind, Brain and Behavior, Philipps University Marburg, Germany
| | - D J Pedrosa
- Department of Neurology, University Hospital Marburg, Philipps University Marburg, Germany
| | - L Timmermann
- Department of Neurology, University Hospital Marburg, Philipps University Marburg, Germany; Center for Mind, Brain and Behavior, Philipps University Marburg, Germany
| | - T Kircher
- Department of Psychiatry and Psychotherapy, University Hospital Marburg, Philipps University Marburg, Germany; Center for Mind, Brain and Behavior, Philipps University Marburg, Germany
| | - I Nenadić
- Department of Psychiatry and Psychotherapy, University Hospital Marburg, Philipps University Marburg, Germany; Center for Mind, Brain and Behavior, Philipps University Marburg, Germany
| | - S Knake
- Epilepsy Center Hesse, Department of Neurology, University Hospital Marburg, Philipps-University Marburg, Germany; Center for Personalized Translational Epilepsy Research, Goethe University Frankfurt, Germany; Center for Mind, Brain and Behavior, Philipps University Marburg, Germany; Core Facility Brain Imaging, Philipps University Marburg, Germany
| |
Collapse
|
12
|
Zhang B, Zhang S, Zhang S. Whole brain alignment of spatial transcriptomics between humans and mice with BrainAlign. Nat Commun 2024; 15:6302. [PMID: 39080277 PMCID: PMC11289418 DOI: 10.1038/s41467-024-50608-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Accepted: 07/10/2024] [Indexed: 08/02/2024] Open
Abstract
The increasing utilization of mouse models in human neuroscience research places higher demands on computational methods to translate findings from the mouse brain to the human one. In this study, we develop BrainAlign, a self-supervised learning approach, for the whole brain alignment of spatial transcriptomics (ST) between humans and mice. BrainAlign encodes spots and genes simultaneously in two separated shared embedding spaces by a heterogeneous graph neural network. We demonstrate that BrainAlign could integrate cross-species spots into the embedding space and reveal the conserved brain regions supported by ST information, which facilitates the detection of homologous regions between humans and mice. Genomic analysis further presents gene expression connections between humans and mice and reveals similar expression patterns for marker genes. Moreover, BrainAlign can accurately map spatially similar homologous regions or clusters onto a unified spatial structural domain while preserving their relative positions.
Collapse
Affiliation(s)
- Biao Zhang
- School of Mathematical Sciences, Fudan University, Shanghai, China
| | - Shuqin Zhang
- School of Mathematical Sciences, Fudan University, Shanghai, China.
- Key Laboratory of Mathematics for Nonlinear Science, Fudan University, Ministry of Education, Shanghai, China.
- Shanghai Key Laboratory for Contemporary Applied Mathematics, Fudan University, Shanghai, China.
| | - Shihua Zhang
- NCMIS, CEMS, RCSDS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, China.
- School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, China.
- Key Laboratory of Systems Health Science of Zhejiang Province, School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Hangzhou, China.
| |
Collapse
|
13
|
Ye Y, Wang Y, Zhuang Y, Tan H, Zuo Z, Yun H, Yuan K, Zhou W. Decomposition of an odorant in olfactory perception and neural representation. Nat Hum Behav 2024; 8:1150-1162. [PMID: 38499771 DOI: 10.1038/s41562-024-01849-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 02/19/2024] [Indexed: 03/20/2024]
Abstract
Molecules-the elementary units of substances-are commonly considered the units of processing in olfactory perception, giving rise to undifferentiated odour objects invariant to environmental variations. By selectively perturbing the processing of chemical substructures with adaptation ('the psychologist's microelectrode') in a series of psychophysical and neuroimaging experiments (458 participants), we show that two perceptually distinct odorants sharing part of their structural features become significantly less discernible following adaptation to a third odorant containing their non-shared structural features, in manners independent of olfactory intensity, valence, quality or general olfactory adaptation. The effect is accompanied by reorganizations of ensemble activity patterns in the posterior piriform cortex that parallel subjective odour quality changes, in addition to substructure-based neural adaptations in the anterior piriform cortex and amygdala. Central representations of odour quality and the perceptual outcome thus embed submolecular structural information and are malleable by recent olfactory encounters.
Collapse
Affiliation(s)
- Yuting Ye
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- Institute of Psychology, School of Public Affairs, Xiamen University, Xiamen, China
| | - Yanqing Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- School of Psychology, Northwest Normal University, Lanzhou, China
| | - Yuan Zhuang
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Huibang Tan
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Zhentao Zuo
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China
- Sino-Dannish College, University of Chinese Academy of Sciences, Beijing, China
| | - Hanqi Yun
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Kaiqi Yuan
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Wen Zhou
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
- Chinese Institute for Brain Research, Beijing, China.
| |
Collapse
|
14
|
Zak JD, Reddy G, Konanur V, Murthy VN. Distinct information conveyed to the olfactory bulb by feedforward input from the nose and feedback from the cortex. Nat Commun 2024; 15:3268. [PMID: 38627390 PMCID: PMC11021479 DOI: 10.1038/s41467-024-47366-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 03/29/2024] [Indexed: 04/19/2024] Open
Abstract
Sensory systems are organized hierarchically, but feedback projections frequently disrupt this order. In the olfactory bulb (OB), cortical feedback projections numerically match sensory inputs. To unravel information carried by these two streams, we imaged the activity of olfactory sensory neurons (OSNs) and cortical axons in the mouse OB using calcium indicators, multiphoton microscopy, and diverse olfactory stimuli. Here, we show that odorant mixtures of increasing complexity evoke progressively denser OSN activity, yet cortical feedback activity is of similar sparsity for all stimuli. Also, representations of complex mixtures are similar in OSNs but are decorrelated in cortical axons. While OSN responses to increasing odorant concentrations exhibit a sigmoidal relationship, cortical axonal responses are complex and nonmonotonic, which can be explained by a model with activity-dependent feedback inhibition in the cortex. Our study indicates that early-stage olfactory circuits have access to local feedforward signals and global, efficiently formatted information about odor scenes through cortical feedback.
Collapse
Affiliation(s)
- Joseph D Zak
- Department of Biological Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA.
- Department of Psychology, University of Illinois Chicago, Chicago, IL, 60607, USA.
| | - Gautam Reddy
- Physics & Informatics Laboratories, NTT Research, Inc., Sunnyvale, CA, 94085, USA
- Department of Physics, Princeton University, Princeton, NJ, 08540, USA
- Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA
| | - Vaibhav Konanur
- Department of Biological Sciences, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Venkatesh N Murthy
- Center for Brain Science, Harvard University, Cambridge, MA, 02138, USA
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, 02138, USA
- Kempner Institute for the Study of Natural and Artificial Intelligence, Harvard University, Allston, 02134, USA
| |
Collapse
|
15
|
Okumura T, Kida I, Yokoi A, Nakai T, Nishimoto S, Touhara K, Okamoto M. Semantic context-dependent neural representations of odors in the human piriform cortex revealed by 7T MRI. Hum Brain Mapp 2024; 45:e26681. [PMID: 38656060 PMCID: PMC11041378 DOI: 10.1002/hbm.26681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 03/23/2024] [Accepted: 03/28/2024] [Indexed: 04/26/2024] Open
Abstract
Olfactory perception depends not only on olfactory inputs but also on semantic context. Although multi-voxel activity patterns of the piriform cortex, a part of the primary olfactory cortex, have been shown to represent odor perception, it remains unclear whether semantic contexts modulate odor representation in this region. Here, we investigated whether multi-voxel activity patterns in the piriform cortex change when semantic context modulates odor perception and, if so, whether the modulated areas communicate with brain regions involved in semantic and memory processing beyond the piriform cortex. We also explored regional differences within the piriform cortex, which are influenced by olfactory input and semantic context. We used 2 × 2 combinations of word labels and odorants that were perceived as congruent and measured piriform activity with a 1-mm isotropic resolution using 7T MRI. We found that identical odorants labeled with different words were perceived differently. This labeling effect was observed in multi-voxel activity patterns in the piriform cortex, as the searchlight decoding analysis distinguished identical odors with different labels for half of the examined stimulus pairs. Significant functional connectivity was observed between parts of the piriform cortex that were modulated by labels and regions associated with semantic and memory processing. While the piriform multi-voxel patterns evoked by different olfactory inputs were also distinguishable, the decoding accuracy was significant for only one stimulus pair, preventing definitive conclusions regarding the locational differences between areas influenced by word labels and olfactory inputs. These results suggest that multi-voxel patterns of piriform activity can be modulated by semantic context, possibly due to communication between the piriform cortex and the semantic and memory regions.
Collapse
Affiliation(s)
- Toshiki Okumura
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of TokyoTokyoJapan
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT)OsakaJapan
| | - Ikuhiro Kida
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT)OsakaJapan
- Graduate School of Frontier Biosciences, Osaka UniversityOsakaJapan
| | - Atsushi Yokoi
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT)OsakaJapan
- Graduate School of Frontier Biosciences, Osaka UniversityOsakaJapan
| | - Tomoya Nakai
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT)OsakaJapan
| | - Shinji Nishimoto
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology (NICT)OsakaJapan
- Graduate School of Frontier Biosciences, Osaka UniversityOsakaJapan
| | - Kazushige Touhara
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of TokyoTokyoJapan
- International Research Center for Neurointelligence (WPI‐IRCN), Institutes for Advanced Study, The University of TokyoTokyoJapan
| | - Masako Okamoto
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of TokyoTokyoJapan
| |
Collapse
|
16
|
Mignot C, Weise S, Podlesek D, Leonhardt G, Bensafi M, Hummel T. What do brain oscillations tell about the human sense of smell? J Neurosci Res 2024; 102:e25335. [PMID: 38634155 DOI: 10.1002/jnr.25335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 04/04/2024] [Accepted: 04/06/2024] [Indexed: 04/19/2024]
Abstract
Brain activity may manifest itself as oscillations which are repetitive rhythms of neuronal firing. These local field potentials can be measured via intracranial electroencephalography (iEEG). This review focuses on iEEG used to map human brain structures involved in olfaction. After presenting the methodology of the review, a summary of the brain structures involved in olfaction is given, followed by a review of the literature on human olfactory oscillations in different contexts. A single case is provided as an illustration of the olfactory oscillations. Overall, the timing and sequence of oscillations found in the different structures of the olfactory system seem to play an important role for olfactory perception.
Collapse
Affiliation(s)
- Coralie Mignot
- Smell & Taste Clinic, Department of Otorhinolaryngology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Susanne Weise
- Smell & Taste Clinic, Department of Otorhinolaryngology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Dino Podlesek
- Department of Neurosurgery, Technische Universität Dresden, Dresden, Germany
| | - Georg Leonhardt
- Department of Neurosurgery, Technische Universität Dresden, Dresden, Germany
| | - Moustafa Bensafi
- Lyon Neuroscience Research Center, CNRS-INSERM-University Claude Bernard of Lyon, CH Le Vinatier, Lyon, France
| | - Thomas Hummel
- Smell & Taste Clinic, Department of Otorhinolaryngology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
17
|
Sharma AA, Nenert R, Goodman AM, Szaflarski JP. Brain temperature and free water increases after mild COVID-19 infection. Sci Rep 2024; 14:7450. [PMID: 38548815 PMCID: PMC10978935 DOI: 10.1038/s41598-024-57561-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 03/19/2024] [Indexed: 04/01/2024] Open
Abstract
The pathophysiology underlying the post-acute sequelae of COVID-19 remains understudied and poorly understood, particularly in healthy adults with a history of mild infection. Chronic neuroinflammation may underlie these enduring symptoms, but studying neuroinflammatory phenomena in vivo is challenging, especially without a comparable pre-COVID-19 dataset. In this study, we present a unique dataset of 10 otherwise healthy individuals scanned before and after experiencing mild COVID-19. Two emerging MR-based methods were used to map pre- to post-COVID-19 brain temperature and free water changes. Post-COVID-19 brain temperature and free water increases, which are indirect biomarkers of neuroinflammation, were found in structures functionally associated with olfactory, cognitive, and memory processing. The largest pre- to post-COVID brain temperature increase was observed in the left olfactory tubercle (p = 0.007, 95% CI [0.48, 3.01]), with a mean increase of 1.75 °C. Notably, the olfactory tubercle is also the region of the primary olfactory cortex where participants with chronic olfactory dysfunction showed the most pronounced increases as compared to those without lingering olfactory dysfunction (adjusted pFDR = 0.0189, 95% CI [1.42, 5.27]). These preliminary insights suggest a potential link between neuroinflammation and chronic cognitive and olfactory dysfunction following mild COVID-19, although further investigations are needed to improve our understanding of what underlies these phenomena.
Collapse
Affiliation(s)
- Ayushe A Sharma
- Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham (UAB), 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35294-0021, USA.
- Department of Neurobiology, University of Alabama at Birmingham (UAB), Birmingham, AL, USA.
| | - Rodolphe Nenert
- Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham (UAB), 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35294-0021, USA
| | - Adam M Goodman
- Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham (UAB), 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35294-0021, USA
| | - Jerzy P Szaflarski
- Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham (UAB), 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35294-0021, USA.
- Department of Neurobiology, University of Alabama at Birmingham (UAB), Birmingham, AL, USA.
- Department of Neurosurgery, University of Alabama at Birmingham (UAB), Birmingham, AL, USA.
- University of Alabama at Birmingham Epilepsy Center (UABEC), Birmingham, AL, USA.
| |
Collapse
|
18
|
Florean I, Vergobbi P, Tomasino B, Nilo A, Guarracino I, Skrap M, Verriello L, Valente M, Ius T, Pauletto G. An "epileptic scent": Olfactory auras in tumor-related epilepsy. Epilepsy Behav 2024; 151:109642. [PMID: 38242066 DOI: 10.1016/j.yebeh.2024.109642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 01/07/2024] [Accepted: 01/10/2024] [Indexed: 01/21/2024]
Abstract
OBJECTIVES To characterize a profile for patients with tumor-related epilepsy presenting olfactory auras. MATERIALS AND METHODS We conducted a monocentric, retrospective study on patients who underwent surgery in the Neurosurgery Unit of Udine University Hospital (Udine, Italy), between the 1st of January 2010 and the 1st of January 2019, for primary brain tumors (PBTs) involving the temporal lobe and the insula. All patients were affected by tumor-related epilepsy; the study group presented olfactory auras as well. We collected neuroradiological, neuropsychological and neurophysiological data from patients' medical charts. RESULTS The subtraction analysis of MRI data shows maximum lesion overlay in left olfactory cortex, left and right hippocampus, left amygdala, right rolandic operculum, right inferior frontal gyrus and right middle temporal gyrus. The presence of olfactory auras did not influence seizure outcome (p = 0.500) or tumor recurrence after surgery (p = 0.185). The type of auras (elementary vs. complex), also, did not influence seizure control (p = 0.222). DISCUSSION In presence of olfactory auras, anterior and mesial temporal regions are mainly involved, such as olfactory cortex, amygdala, and anterior hippocampus, together with right rolandic operculum, right inferior frontal gyrus and right middle temporal gyrus, suggesting their possible role in the genesis of olfactory auras. Post-surgical seizure outcome and disease relapse are not influenced by neither the presence nor the type of olfactory auras. CONCLUSIONS Olfactory auras are rare event, however they may be often underestimated by the patients and under-investigated by the clinicians, even when their occurrence can represent a useful localizing tool.
Collapse
Affiliation(s)
- Irene Florean
- Department of Medical Area, University of Udine, Udine, Italy.
| | - Pietro Vergobbi
- Department of Medical Area, University of Udine, Udine, Italy.
| | - Barbara Tomasino
- Scientific Institute, IRCCS E. Medea, Department/Unit Pasian di Prato, Udine, Italy.
| | - Annacarmen Nilo
- Department of Medical Area, University of Udine, Udine, Italy; Clinical Neurology Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, Udine, Italy.
| | - Ilaria Guarracino
- Scientific Institute, IRCCS E. Medea, Department/Unit Pasian di Prato, Udine, Italy.
| | - Miran Skrap
- Neurosurgery Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, Udine, Italy
| | - Lorenzo Verriello
- Neurology Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, Udine, Italy.
| | - Mariarosaria Valente
- Department of Medical Area, University of Udine, Udine, Italy; Clinical Neurology Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, Udine, Italy.
| | - Tamara Ius
- Neurosurgery Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, Udine, Italy.
| | - Giada Pauletto
- Neurology Unit, Head-Neck and Neurosciences Department, Santa Maria della Misericordia University Hospital, Udine, Italy.
| |
Collapse
|
19
|
Abstract
Historically, the human sense of smell has been regarded as the odd stepchild of the senses, especially compared to the sensory bravado of seeing, touching, and hearing. The idea that the human olfaction has little to contribute to our experience of the world is commonplace, though with the emergence of COVID-19 there has rather been a sea change in this understanding. An ever increasing body of work has convincingly highlighted the keen capabilities of the human nose and the sophistication of the human olfactory system. Here, we provide a concise overview of the neuroscience of human olfaction spanning the last 10-15 years, with focus on the peripheral and central mechanisms that underlie how odor information is processed, packaged, parceled, predicted, and perturbed to serve odor-guided behaviors. We conclude by offering some guideposts for harnessing the next decade of olfactory research in all its shapes and forms.
Collapse
Affiliation(s)
| | - Jay A Gottfried
- Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA; ,
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
20
|
Ekanayake A, Peiris S, Kanekar S, Tobia M, Yang Q, Ahmed B, McCaslin S, Kalra D, Eslinger P, Karunanayaka P. Monorhinal and birhinal odor processing in humans: an fMRI investigation. Chem Senses 2024; 49:bjae038. [PMID: 39387136 PMCID: PMC11582365 DOI: 10.1093/chemse/bjae038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Indexed: 10/12/2024] Open
Abstract
The olfactory nerve, also known as cranial nerve I, is known to have exclusive ipsilateral projections to primary olfactory cortical structures. However, the lateralization of olfactory processes is known to depend on the task and nature of stimuli. It still remains unclear whether olfactory system projections in humans also correspond to functional pathways during olfactory tasks without any trigeminal, perceptual, or cognitive-motor components. Twenty young healthy subjects with a normal sense of smell took part in an olfactory functional magnetic resonance imaging (fMRI) study. We used 2 types of nostril-specific stimulation, passive (no sniffing), and active (with sniffing), with phenyl ethyl alcohol, a pure olfactory stimulant, to investigate fMRI activity patterns in primary and secondary olfactory-related brain structures. Irrespective of the stimulated nostril and the type of stimulation, we detected symmetrical activity in primary and secondary olfactory-related brain structures such as the primary olfactory cortex, entorhinal cortex, and orbitofrontal cortex. In the absence of perceptual or cognitive-motor task demands, the perception of monorhinally presented pure odors is processed bilaterally in the brain.
Collapse
Affiliation(s)
- Anupa Ekanayake
- Grodno State Medical University, Grodno, Belarus
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
| | - Senal Peiris
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
| | - Sangam Kanekar
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
| | - Michael Tobia
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
| | - Qing Yang
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
- Department of Neurosurgery, Penn State University College of Medicine, Hershey, PA, United States
| | - Biyar Ahmed
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
| | - Silas McCaslin
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
| | - Deepak Kalra
- Department of Neurology, Penn State University College of Medicine, Hershey, PA, United States
| | - Paul Eslinger
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
- Department of Neurology, Penn State University College of Medicine, Hershey, PA, United States
| | - Prasanna Karunanayaka
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, United States
| |
Collapse
|
21
|
Ma Y, Jiang J, Wu Y, Xiong J, Lv H, Li J, Kuang H, Jiang X, Chen Y. Abnormal functional connectivity of the core olfactory network in patients with chronic rhinosinusitis accompanied by olfactory dysfunction. Front Neurol 2023; 14:1295556. [PMID: 38046577 PMCID: PMC10690368 DOI: 10.3389/fneur.2023.1295556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 11/03/2023] [Indexed: 12/05/2023] Open
Abstract
Objective To review and analyze the functional connectivity (FC) abnormalities in the brain olfactory network (ON) of patients with chronic rhinosinusitis with olfactory dysfunction (CRSwOD) and explore the relationship between these FC abnormalities and olfactory dysfunction, providing clues to the neurophysiological mechanisms underlying CRSwOD. Methods FC analysis on the ON of patients with CRSwOD and patients with chronic rhinosinusitis without olfactory dysfunction (CRSsOD) identified the regions of the ON with abnormal FC in CRSwOD patients, and the correlation between abnormal FC and clinical scales for chronic rhinosinusitis was analyzed. Results (1) Compared with the CRSsOD group, CRSwOD patients showed decreased FC between the bilateral orbitofrontal cortex (OFC) and the right middle frontal gyrus, (2) Receiver operating characteristic (ROC) curve analysis revealed that the FC value between the right middle frontal gyrus and the left OFC (area under the curve (AUC) = 0.852, sensitivity: 0.821, specificity: 0.800, p < 0.001) was more capable of distinguishing whether CRS patients may have olfactory dysfunction than the FC value between the right middle frontal gyrus and the right OFC (AUC = 0.827, sensitivity: 0.893, specificity: 0.667, p < 0.001), and (3) Lund-Kennedy scores were positively correlated with the FC values between the right middle frontal gyrus and the left OFC (r = 0.443, p < 0.018). Lund-Mackay scores were also positively correlated with the FC values between the right middle frontal gyrus and the left OFC (r = 0.468, p < 0.012). Questionnaire of Olfactory Disorders-Negative Statements scores were negatively correlated with the FC values between the right middle frontal gyrus and the left OFC (r = -0.481, p < 0.001). Conclusion Persistent nasal inflammation affects the FC between the middle frontal gyrus and the OFC, which may serve as a potential imaging marker for identifying CRSwOD. The severity of nasal inflammation and olfactory damage is closely related to the FC between the middle frontal gyrus and OFC, and the abnormal changes in this FC can be used to explain the neurophysiological mechanisms behind the occurrence of olfactory dysfunction in patients.
Collapse
Affiliation(s)
- Yao Ma
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang, China
- Department of Radiology, The Third Hospital of Nanchang, Nanchang, Jiangxi, China
| | - Jian Jiang
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang, China
| | - Ying Wu
- Department of Radiology, The Second Affiliated Hospital, Nanchang University, Nanchang, China
| | - Jiaxin Xiong
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang, China
| | - Huiting Lv
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang, China
| | - Jiahao Li
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Hongmei Kuang
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang, China
| | - Xiaofeng Jiang
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang, China
| | - Yeyuan Chen
- Department of Radiology, The First Affiliated Hospital, Nanchang University, Nanchang, China
| |
Collapse
|
22
|
Perszyk EE, Davis XS, Djordjevic J, Jones-Gotman M, Trinh J, Hutelin Z, Veldhuizen MG, Koban L, Wager TD, Kober H, Small DM. Odour-imagery ability is linked to food craving, intake, and adiposity change in humans. Nat Metab 2023; 5:1483-1493. [PMID: 37640944 DOI: 10.1038/s42255-023-00874-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 07/25/2023] [Indexed: 08/31/2023]
Abstract
It is well-known that food-cue reactivity (FCR) is positively associated with body mass index (BMI)1 and weight change2, but the mechanisms underlying these relationships are incompletely understood. One prominent theory of craving posits that the elaboration of a desired substance through sensory imagery intensifies cravings, thereby promoting consumption3. Olfaction is integral to food perception, yet the ability to imagine odours varies widely4. Here we test in a basic observational study whether this large variation in olfactory imagery drives FCR strength to promote adiposity in 45 adults (23 male). We define odour-imagery ability as the extent to which imagining an odour interferes with the detection of a weak incongruent odour (the 'interference effect'5). As predicted in our preregistration, the interference effect correlates with the neural decoding of imagined, but not real, odours. These perceptual and neural measures of odour imagery are in turn associated with FCR, defined by the rated craving intensity of liked foods and cue-potentiated intake. Finally, odour imagery exerts positive indirect effects on changes in BMI and body-fat percentage over one year via its influences on FCR. These findings establish odour imagery as a driver of FCR that in turn confers risk for weight gain.
Collapse
Affiliation(s)
- Emily E Perszyk
- Modern Diet and Physiology Research Center, New Haven, CT, USA.
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
| | - Xue S Davis
- Modern Diet and Physiology Research Center, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Jelena Djordjevic
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Marilyn Jones-Gotman
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Jessica Trinh
- Modern Diet and Physiology Research Center, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Zach Hutelin
- Modern Diet and Physiology Research Center, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Maria G Veldhuizen
- Department of Anatomy, Faculty of Medicine, Mersin University, Ciftlikkoy Campus, Mersin, Turkey
| | - Leonie Koban
- Lyon Neuroscience Research Center (CRNL), CNRS, INSERM, University Claude Bernard Lyon 1, Bron, France
| | - Tor D Wager
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH, USA
| | - Hedy Kober
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychology, Yale University, New Haven, CT, USA
| | - Dana M Small
- Modern Diet and Physiology Research Center, New Haven, CT, USA.
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.
- Department of Psychology, Yale University, New Haven, CT, USA.
- Department of Medicine, McGill University Health Center, Montreal, Quebec, Canada.
| |
Collapse
|
23
|
Sagar V, Shanahan LK, Zelano CM, Gottfried JA, Kahnt T. High-precision mapping reveals the structure of odor coding in the human brain. Nat Neurosci 2023; 26:1595-1602. [PMID: 37620443 PMCID: PMC10726579 DOI: 10.1038/s41593-023-01414-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 07/18/2023] [Indexed: 08/26/2023]
Abstract
Odor perception is inherently subjective. Previous work has shown that odorous molecules evoke distributed activity patterns in olfactory cortices, but how these patterns map on to subjective odor percepts remains unclear. In the present study, we collected neuroimaging responses to 160 odors from 3 individual subjects (18 h per subject) to probe the neural coding scheme underlying idiosyncratic odor perception. We found that activity in the orbitofrontal cortex (OFC) represents the fine-grained perceptual identity of odors over and above coarsely defined percepts, whereas this difference is less pronounced in the piriform cortex (PirC) and amygdala. Furthermore, the implementation of perceptual encoding models enabled us to predict olfactory functional magnetic resonance imaging responses to new odors, revealing that the dimensionality of the encoded perceptual spaces increases from the PirC to the OFC. Whereas encoding of lower-order dimensions generalizes across subjects, encoding of higher-order dimensions is idiosyncratic. These results provide new insights into cortical mechanisms of odor coding and suggest that subjective olfactory percepts reside in the OFC.
Collapse
Affiliation(s)
- Vivek Sagar
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | | | - Christina M Zelano
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Jay A Gottfried
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Thorsten Kahnt
- National Institute on Drug Abuse Intramural Research Program, Baltimore, MD, USA.
| |
Collapse
|
24
|
Ekanayake A, Yang Q, Kanekar S, Ahmed B, McCaslin S, Kalra D, Eslinger P, Karunanayaka P. Monorhinal and Birhinal Odor Processing in Humans: an fMRI investigation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.01.551475. [PMID: 37577649 PMCID: PMC10418263 DOI: 10.1101/2023.08.01.551475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The olfactory nerve, also known as cranial nerve I, is known to have exclusive ipsilateral projections to primary olfactory cortical structures. It is still unclear whether these projections also correspond to functional pathways of odor processing. In an olfactory functional magnetic resonance imaging (fMRI) study of twenty young healthy subjects with a normal sense of smell, we tested whether nostril specific stimulation with phenyl ethyl alcohol (PEA), a pure olfactory stimulant, asymmetrically activates primary or secondary olfactory-related brain structures such as primary olfactory cortex, entorhinal cortex, and orbitofrontal cortex. The results indicated that without a challenging olfactory task, passive (no sniffing) and active (with sniffing) nostril-specific PEA stimulation did not produce asymmetrical fMRI activation in olfactory cortical structures.
Collapse
Affiliation(s)
- Anupa Ekanayake
- Grodno State Medical University, Grodno, Belarus
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Qing Yang
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
- Department of Neurosurgery, Penn State University College of Medicine, Hershey, PA, USA
| | - Sangam Kanekar
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Biyar Ahmed
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Silas McCaslin
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| | - Deepak Kalra
- Department of Neurology, Penn State University College of Medicine, Hershey, PA, USA
| | - Paul Eslinger
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
- Department of Neurology, Penn State University College of Medicine, Hershey, PA, USA
| | - Prasanna Karunanayaka
- Department of Radiology, Penn State University College of Medicine, Hershey, PA, USA
| |
Collapse
|
25
|
Steinbart D, Yaakub SN, Steinbrenner M, Guldin LS, Holtkamp M, Keller SS, Weber B, Rüber T, Heckemann RA, Ilyas-Feldmann M, Hammers A. Automatic and manual segmentation of the piriform cortex: Method development and validation in patients with temporal lobe epilepsy and Alzheimer's disease. Hum Brain Mapp 2023; 44:3196-3209. [PMID: 37052063 PMCID: PMC10171523 DOI: 10.1002/hbm.26274] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 02/10/2023] [Accepted: 02/24/2023] [Indexed: 04/14/2023] Open
Abstract
The piriform cortex (PC) is located at the junction of the temporal and frontal lobes. It is involved physiologically in olfaction as well as memory and plays an important role in epilepsy. Its study at scale is held back by the absence of automatic segmentation methods on MRI. We devised a manual segmentation protocol for PC volumes, integrated those manually derived images into the Hammers Atlas Database (n = 30) and used an extensively validated method (multi-atlas propagation with enhanced registration, MAPER) for automatic PC segmentation. We applied automated PC volumetry to patients with unilateral temporal lobe epilepsy with hippocampal sclerosis (TLE; n = 174 including n = 58 controls) and to the Alzheimer's Disease Neuroimaging Initiative cohort (ADNI; n = 151, of whom with mild cognitive impairment (MCI), n = 71; Alzheimer's disease (AD), n = 33; controls, n = 47). In controls, mean PC volume was 485 mm3 on the right and 461 mm3 on the left. Automatic and manual segmentations overlapped with a Jaccard coefficient (intersection/union) of ~0.5 and a mean absolute volume difference of ~22 mm3 in healthy controls, ~0.40/ ~28 mm3 in patients with TLE, and ~ 0.34/~29 mm3 in patients with AD. In patients with TLE, PC atrophy lateralised to the side of hippocampal sclerosis (p < .001). In patients with MCI and AD, PC volumes were lower than those of controls bilaterally (p < .001). Overall, we have validated automatic PC volumetry in healthy controls and two types of pathology. The novel finding of early atrophy of PC at the stage of MCI possibly adds a novel biomarker. PC volumetry can now be applied at scale.
Collapse
Affiliation(s)
- David Steinbart
- Charité - Universitätsmedizin Berlin, Freie Universität and Humboldt-Universität zu Berlin, Department of Neurology, Epilepsy-Center Berlin-Brandenburg, Berlin, Germany
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, London, UK
| | - Siti N Yaakub
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, London, UK
- School of Psychology, Faculty of Health, University of Plymouth, Plymouth, UK
| | - Mirja Steinbrenner
- Charité - Universitätsmedizin Berlin, Freie Universität and Humboldt-Universität zu Berlin, Department of Neurology, Epilepsy-Center Berlin-Brandenburg, Berlin, Germany
| | - Lynn S Guldin
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, London, UK
| | - Martin Holtkamp
- Charité - Universitätsmedizin Berlin, Freie Universität and Humboldt-Universität zu Berlin, Department of Neurology, Epilepsy-Center Berlin-Brandenburg, Berlin, Germany
| | - Simon S Keller
- Department of Pharmacology and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
- Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
| | - Bernd Weber
- Center for Economics and Neuroscience, University of Bonn, Bonn, Germany
- Institute of Experimental Epileptology and Cognition Research, University Hospital Bonn, Bonn, Germany
| | - Theodor Rüber
- Institute of Experimental Epileptology and Cognition Research, University Hospital Bonn, Bonn, Germany
| | - Rolf A Heckemann
- Department of Medical Radiation Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Maria Ilyas-Feldmann
- Charité - Universitätsmedizin Berlin, Freie Universität and Humboldt-Universität zu Berlin, Department of Neurology, Epilepsy-Center Berlin-Brandenburg, Berlin, Germany
| | - Alexander Hammers
- King's College London & Guy's and St Thomas' PET Centre, School of Biomedical Engineering and Imaging Sciences, St Thomas' Hospital, London, UK
| |
Collapse
|
26
|
Perszyk EE, Davis XS, Djordjevic J, Jones-Gotman M, Trinh J, Hutelin Z, Veldhuizen MG, Koban L, Wager TD, Kober H, Small DM. Odor imagery but not perception drives risk for food cue reactivity and increased adiposity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.06.527292. [PMID: 36798231 PMCID: PMC9934556 DOI: 10.1101/2023.02.06.527292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Mental imagery has been proposed to play a critical role in the amplification of cravings. Here we tested whether olfactory imagery drives food cue reactivity strength to promote adiposity in 45 healthy individuals. We measured odor perception, odor imagery ability, and food cue reactivity using self-report, perceptual testing, and neuroimaging. Adiposity was assessed at baseline and one year later. Brain responses to real and imagined odors were analyzed with univariate and multivariate decoding methods to identify pattern-based olfactory codes. We found that the accuracy of decoding imagined, but not real, odor quality correlated with a perceptual measure of odor imagery ability and with greater adiposity changes. This latter relationship was mediated by cue-potentiated craving and intake. Collectively, these findings establish odor imagery ability as a risk factor for weight gain and more specifically as a mechanism by which exposure to food cues promotes craving and overeating.
Collapse
Affiliation(s)
- Emily E. Perszyk
- Modern Diet and Physiology Research Center, New Haven, CT 06510, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Xue S. Davis
- Modern Diet and Physiology Research Center, New Haven, CT 06510, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Jelena Djordjevic
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada
| | - Marilyn Jones-Gotman
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montréal, QC H3A 2B4, Canada
| | - Jessica Trinh
- Modern Diet and Physiology Research Center, New Haven, CT 06510, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Zach Hutelin
- Modern Diet and Physiology Research Center, New Haven, CT 06510, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Maria G. Veldhuizen
- Department of Anatomy, Faculty of Medicine, Mersin University, Ciftlikkoy Campus, Mersin 33343, Turkey
| | - Leonie Koban
- Lyon Neuroscience Research Center (CRNL), CNRS, INSERM, University Claude Bernard Lyon 1, France
| | - Tor D. Wager
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Hedy Kober
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
- Department of Psychology, Yale University, New Haven, CT 06511, USA
| | - Dana M. Small
- Modern Diet and Physiology Research Center, New Haven, CT 06510, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06511, USA
- Department of Psychology, Yale University, New Haven, CT 06511, USA
| |
Collapse
|
27
|
Odor discrimination is immune to the effects of verbal labels. Sci Rep 2023; 13:1742. [PMID: 36720925 PMCID: PMC9889793 DOI: 10.1038/s41598-023-28134-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 01/13/2023] [Indexed: 02/01/2023] Open
Abstract
For many odors that we encounter in daily life, we perceive their qualities without being able to specifically identify their sources-an experience termed the "tip-of-the-nose" phenomenon. Does learning an odor's identity alter our experience of it? Past work has shown that labeling odors can alter how we describe and react to them, but it remains an open question whether such changes extend to the level of perception, making an odor actually smell different. Here, in a set of odor classification experiments we tested whether attaching labels to odors can alter their perceptual discriminability. We found that even for odors whose reported similarity changed markedly when their identities were revealed, their discriminability remained unchanged by labels. Our findings indicate that two critical functions of olfaction-parsing the odor environment and supporting the subjective experience of odor qualities-access distinct odor representations within the olfactory processing stream.
Collapse
|
28
|
Kob L. Exploring the role of structuralist methodology in the neuroscience of consciousness: a defense and analysis. Neurosci Conscious 2023; 2023:niad011. [PMID: 37205986 PMCID: PMC10191193 DOI: 10.1093/nc/niad011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 02/27/2023] [Accepted: 04/13/2023] [Indexed: 05/21/2023] Open
Abstract
Traditional contrastive analysis has been the foundation of consciousness science, but its limitations due to the lack of a reliable method for measuring states of consciousness have prompted the exploration of alternative approaches. Structuralist theories have gained attention as an alternative that focuses on the structural properties of phenomenal experience and seeks to identify their neural encoding via structural similarities between quality spaces and neural state spaces. However, the intertwining of philosophical assumptions about structuralism and structuralist methodology may pose a challenge to those who are skeptical of the former. In this paper, I offer an analysis and defense of structuralism as a methodological approach in consciousness science, which is partly independent of structuralist assumptions on the nature of consciousness. By doing so, I aim to make structuralist methodology more accessible to a broader scientific and philosophical audience. I situate methodological structuralism in the context of questions concerning mental representation, psychophysical measurement, holism, and functional relevance of neural processes. At last, I analyze the relationship between the structural approach and the distinction between conscious and unconscious states.
Collapse
Affiliation(s)
- Lukas Kob
- *Corresponding author. Philosophy Department, Otto-von-Guericke University, Zschokkestraße 32, Magdeburg 39104, Germany. E-mail:
| |
Collapse
|
29
|
Perszyk EE, Davis XS, Small DM. Olfactory decoding is positively associated with ad libitum food intake in sated humans. Appetite 2023; 180:106351. [PMID: 36270421 DOI: 10.1016/j.appet.2022.106351] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/06/2022]
Abstract
The role of olfaction in eating behavior and body weight regulation is controversial. Here we reanalyzed data from a previous functional magnetic resonance imaging study to test whether central olfactory coding is associated with hunger/satiety state, food intake, and change in body weight over one year in healthy human adults. Since odor quality and category are coded across distributed neural patterns that are not discernible with traditional univariate analyses, we used multi-voxel pattern analyses to decode patterns of brain activation to food versus nonfood odors. We found that decoding accuracies in the piriform cortex and amygdala were greater in the sated compared to hungry state. Sated decoding accuracies in these and other regions were also associated with post-scan ad libitum food intake, but not with weight change. These findings demonstrate that the fidelity of olfactory decoding is influenced by meal consumption and is associated with immediate food intake, but not longer-term body weight regulation.
Collapse
Affiliation(s)
- Emily E Perszyk
- Modern Diet and Physiology Research Center, New Haven, CT, 06510, USA; Yale University School of Medicine, Department of Psychiatry, New Haven, CT, 06510, USA.
| | - Xue S Davis
- Modern Diet and Physiology Research Center, New Haven, CT, 06510, USA; Yale University School of Medicine, Department of Psychiatry, New Haven, CT, 06510, USA
| | - Dana M Small
- Modern Diet and Physiology Research Center, New Haven, CT, 06510, USA; Yale University School of Medicine, Department of Psychiatry, New Haven, CT, 06510, USA; Yale University, Department of Psychology, New Haven, CT, 06510, USA.
| |
Collapse
|
30
|
Marvan T, Polák M. Neurocentrist identity theory and neuro-phenomenal typing: A commentary on Manzotti's, "The boundaries and location of consciousness as identity theories deem fit". Front Psychol 2022; 13:1058325. [PMID: 36457935 PMCID: PMC9706188 DOI: 10.3389/fpsyg.2022.1058325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 11/01/2022] [Indexed: 02/28/2024] Open
Affiliation(s)
- Tomáš Marvan
- Department of Analytic Philosophy, Institute of Philosophy, Czech Academy of Sciences, Prague, Czechia
| | - Michal Polák
- Department of Philosophy, University of West Bohemia, Pilsen, Czechia
| |
Collapse
|
31
|
Odor Pleasantness Modulates Functional Connectivity in the Olfactory Hedonic Processing Network. Brain Sci 2022; 12:brainsci12101408. [PMID: 36291341 PMCID: PMC9599424 DOI: 10.3390/brainsci12101408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/10/2022] [Accepted: 10/14/2022] [Indexed: 11/18/2022] Open
Abstract
Olfactory hedonic evaluation is the primary dimension of olfactory perception and thus central to our sense of smell. It involves complex interactions between brain regions associated with sensory, affective and reward processing. Despite a recent increase in interest, several aspects of olfactory hedonic evaluation remain ambiguous: uncertainty surrounds the communication between, and interaction among, brain areas during hedonic evaluation of olfactory stimuli with different levels of pleasantness, as well as the corresponding supporting oscillatory mechanisms. In our study we investigated changes in functional interactions among brain areas in response to odor stimuli using electroencephalography (EEG). To this goal, functional connectivity networks were estimated based on phase synchronization between EEG signals using the weighted phase lag index (wPLI). Graph theoretic metrics were subsequently used to quantify the resulting changes in functional connectivity of relevant brain regions involved in olfactory hedonic evaluation. Our results indicate that odor stimuli of different hedonic values evoke significantly different interaction patterns among brain regions within the olfactory cortex, as well as in the anterior cingulate and orbitofrontal cortices. Furthermore, significant hemispheric laterality effects have been observed in the prefrontal and anterior cingulate cortices, specifically in the beta ((13–30) Hz) and gamma ((30–40) Hz) frequency bands.
Collapse
|
32
|
Bhattarai JP, Etyemez S, Jaaro-Peled H, Janke E, Leon Tolosa UD, Kamiya A, Gottfried JA, Sawa A, Ma M. Olfactory modulation of the medial prefrontal cortex circuitry: Implications for social cognition. Semin Cell Dev Biol 2022; 129:31-39. [PMID: 33975755 PMCID: PMC8573060 DOI: 10.1016/j.semcdb.2021.03.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 10/21/2022]
Abstract
Olfactory dysfunction is manifested in a wide range of neurological and psychiatric diseases, and often emerges prior to the onset of more classical symptoms and signs. From a behavioral perspective, olfactory deficits typically arise in conjunction with impairments of cognition, motivation, memory, and emotion. However, a conceptual framework for explaining the impact of olfactory processing on higher brain functions in health and disease remains lacking. Here we aim to provide circuit-level insights into this question by synthesizing recent advances in olfactory network connectivity with other cortical brain regions such as the prefrontal cortex. We will focus on social cognition as a representative model for exploring and critically evaluating the relationship between olfactory cortices and higher-order cortical regions in rodent models. Although rodents do not recapitulate all dimensions of human social cognition, they have experimentally accessible neural circuits and well-established behavioral tests for social motivation, memory/recognition, and hierarchy, which can be extrapolated to other species including humans. In particular, the medial prefrontal cortex (mPFC) has been recognized as a key brain region in mediating social cognition in both rodents and humans. This review will highlight the underappreciated connectivity, both anatomical and functional, between the olfactory system and mPFC circuitry, which together provide a neural substrate for olfactory modulation of social cognition and social behaviors. We will provide future perspectives on the functional investigation of the olfactory-mPFC circuit in rodent models and discuss how to translate such animal research to human studies.
Collapse
Affiliation(s)
- Janardhan P Bhattarai
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Semra Etyemez
- Department of Psychiatry, John Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Hanna Jaaro-Peled
- Department of Psychiatry, John Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Emma Janke
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Usuy D Leon Tolosa
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Atsushi Kamiya
- Department of Psychiatry, John Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Jay A Gottfried
- Department of Psychology, University of Pennsylvania, School of Arts and Sciences, Philadelphia, PA 19104, USA; Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Akira Sawa
- Department of Psychiatry, John Hopkins University School of Medicine, Baltimore, MD 21287, USA; Departments of Neuroscience, Biomedical Engineering, and Genetic Medicine, John Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Mental Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21287, USA.
| | - Minghong Ma
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
| |
Collapse
|
33
|
Kulason S, Ratnanather JT, Miller MI, Kamath V, Hua J, Yang K, Ma M, Ishizuka K, Sawa A. A comparative neuroimaging perspective of olfaction and higher-order olfactory processing: on health and disease. Semin Cell Dev Biol 2022; 129:22-30. [PMID: 34462249 PMCID: PMC9900497 DOI: 10.1016/j.semcdb.2021.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 08/18/2021] [Indexed: 02/08/2023]
Abstract
Olfactory dysfunction is often the earliest indicator of disease in a range of neurological and psychiatric disorders. One tempting working hypothesis is that pathological changes in the peripheral olfactory system where the body is exposed to many adverse environmental stressors may have a causal role for the brain alteration. Whether and how the peripheral pathology spreads to more central brain regions may be effectively studied in rodent models, and there is successful precedence in experimental models for Parkinson's disease. It is of interest to study whether a similar mechanism may underlie the pathology of psychiatric illnesses, such as schizophrenia. However, direct comparison between rodent models and humans includes challenges under light of comparative neuroanatomy and experimental methodologies used in these two distinct species. We believe that neuroimaging modality that has been the main methodology of human brain studies may be a useful viewpoint to address and fill the knowledge gap between rodents and humans in this scientific question. Accordingly, in the present review article, we focus on brain imaging studies associated with olfaction in healthy humans and patients with neurological and psychiatric disorders, and if available those in rodents. We organize this review article at three levels: 1) olfactory bulb (OB) and peripheral structures of the olfactory system, 2) primary olfactory cortical and subcortical regions, and 3) associated higher-order cortical regions. This research area is still underdeveloped, and we acknowledge that further validation with independent cohorts may be needed for many studies presented here, in particular those with human subjects. Nevertheless, whether and how peripheral olfactory disturbance impacts brain function is becoming even a hotter topic in the ongoing COVID-19 pandemic, given the risk of long-term changes of mental status associated with olfactory infection of SARS-CoV-2. Together, in this review article, we introduce this underdeveloped but important research area focusing on its implications in neurological and psychiatric disorders, with several pioneered publications.
Collapse
Affiliation(s)
- Sue Kulason
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - J Tilak Ratnanather
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Michael I Miller
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Vidyulata Kamath
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Jun Hua
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
| | - Kun Yang
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA
| | - Minghong Ma
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Koko Ishizuka
- Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA
| | - Akira Sawa
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD, USA; Johns Hopkins Schizophrenia Center, Baltimore, MD, USA; Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD, USA; Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| |
Collapse
|
34
|
You Y, Novak LR, Clancy KJ, Li W. Pattern differentiation and tuning shift in human sensory cortex underlie long-term threat memory. Curr Biol 2022; 32:2067-2075.e4. [PMID: 35325599 PMCID: PMC9090975 DOI: 10.1016/j.cub.2022.02.076] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 01/18/2022] [Accepted: 02/28/2022] [Indexed: 12/12/2022]
Abstract
The amygdala-prefrontal-cortex circuit has long occupied the center of the threat system,1 but new evidence has rapidly amassed to implicate threat processing outside this canonical circuit.2-4 Through nonhuman research, the sensory cortex has emerged as a critical substrate for long-term threat memory,5-9 underpinned by sensory cortical pattern separation/completion10,11 and tuning shift.12,13 In humans, research has begun to associate the human sensory cortex with long-term threat memory,14,15 but the lack of mechanistic insights obscures a direct linkage. Toward that end, we assessed human olfactory threat conditioning and long-term (9 days) threat memory, combining affective appraisal, olfactory psychophysics, and functional magnetic resonance imaging (fMRI) over a linear odor-morphing continuum (five levels of binary mixtures of the conditioned stimuli/CS+ and CS- odors). Affective ratings and olfactory perceptual discrimination confirmed (explicit) affective and perceptual learning and memory via conditioning. fMRI representational similarity analysis (RSA) and voxel-based tuning analysis further revealed associative plasticity in the human olfactory (piriform) cortex, including immediate and lasting pattern differentiation between CS and neighboring non-CS and a late onset, lasting tuning shift toward the CS. The two plastic processes were especially salient and lasting in anxious individuals, among whom they were further correlated. These findings thus support an evolutionarily conserved sensory cortical system of long-term threat representation, which can underpin threat perception and memory. Importantly, hyperfunctioning of this sensory mnemonic system of threat in anxiety further implicates a hitherto underappreciated sensory mechanism of anxiety.
Collapse
Affiliation(s)
- Yuqi You
- Department of Psychology, Florida State University, 1107 W. Call St., Tallahassee, FL 32306, USA.
| | - Lucas R Novak
- Department of Psychology, Florida State University, 1107 W. Call St., Tallahassee, FL 32306, USA
| | - Kevin J Clancy
- Department of Psychology, Florida State University, 1107 W. Call St., Tallahassee, FL 32306, USA
| | - Wen Li
- Department of Psychology, Florida State University, 1107 W. Call St., Tallahassee, FL 32306, USA.
| |
Collapse
|
35
|
Coureaud G, Thomas-Danguin T, Sandoz JC, Wilson DA. Biological constraints on configural odour mixture perception. J Exp Biol 2022; 225:274695. [PMID: 35285471 PMCID: PMC8996812 DOI: 10.1242/jeb.242274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Animals, including humans, detect odours and use this information to behave efficiently in the environment. Frequently, odours consist of complex mixtures of odorants rather than single odorants, and mixtures are often perceived as configural wholes, i.e. as odour objects (e.g. food, partners). The biological rules governing this 'configural perception' (as opposed to the elemental perception of mixtures through their components) remain weakly understood. Here, we first review examples of configural mixture processing in diverse species involving species-specific biological signals. Then, we present the original hypothesis that at least certain mixtures can be processed configurally across species. Indeed, experiments conducted in human adults, newborn rabbits and, more recently, in rodents and honeybees show that these species process some mixtures in a remarkably similar fashion. Strikingly, a mixture AB (A, ethyl isobutyrate; B, ethyl maltol) induces configural processing in humans, who perceive a mixture odour quality (pineapple) distinct from the component qualities (A, strawberry; B, caramel). The same mixture is weakly configurally processed in rabbit neonates, which perceive a particular odour for the mixture in addition to the component odours. Mice and honeybees also perceive the AB mixture configurally, as they respond differently to the mixture compared with its components. Based on these results and others, including neurophysiological approaches, we propose that certain mixtures are convergently perceived across various species of vertebrates/invertebrates, possibly as a result of a similar anatomical organization of their olfactory systems and the common necessity to simplify the environment's chemical complexity in order to display adaptive behaviours.
Collapse
Affiliation(s)
- Gérard Coureaud
- Centre de Recherche en Neurosciences de Lyon, Team Sensory Neuroethology (ENES), CNRS/INSERM/UCBL1/UJM, 69500 Lyon, France
| | - Thierry Thomas-Danguin
- Centre des Sciences du Goût et de l'Alimentation, Team Flavor, Food Oral Processing and Perception, INRAE, CNRS, Institut Agro Dijon, Université Bourgogne Franche-Comté, 21000 Dijon, France
| | - Jean-Christophe Sandoz
- Evolution, Genomes, Behavior and Ecology, CNRS, Université Paris-Saclay, IRD, 91190 Gif-sur-Yvette, France
| | - Donald A Wilson
- Department of Child & Adolescent Psychiatry, New York University Langone School of Medicine and Nathan S. Kline Institute for Psychiatric Research, New York, NY 10016, USA
| |
Collapse
|
36
|
Poo C, Agarwal G, Bonacchi N, Mainen ZF. Spatial maps in piriform cortex during olfactory navigation. Nature 2021; 601:595-599. [PMID: 34937941 DOI: 10.1038/s41586-021-04242-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 11/12/2021] [Indexed: 11/10/2022]
Abstract
Odours are a fundamental part of the sensory environment used by animals to guide behaviours such as foraging and navigation1,2. Primary olfactory (piriform) cortex is thought to be the main cortical region for encoding odour identity3-8. Here, using neural ensemble recordings in freely moving rats performing an odour-cued spatial choice task, we show that posterior piriform cortex neurons carry a robust spatial representation of the environment. Piriform spatial representations have features of a learned cognitive map, being most prominent near odour ports, stable across behavioural contexts and independent of olfactory drive or reward availability. The accuracy of spatial information carried by individual piriform neurons was predicted by the strength of their functional coupling to the hippocampal theta rhythm. Ensembles of piriform neurons concurrently represented odour identity as well as spatial locations of animals, forming an odour-place map. Our results reveal a function for piriform cortex in spatial cognition and suggest that it is well-suited to form odour-place associations and guide olfactory-cued spatial navigation.
Collapse
Affiliation(s)
- Cindy Poo
- Champalimaud Foundation, Lisbon, Portugal.
| | - Gautam Agarwal
- W. M. Keck Science Center, The Claremont Colleges, Claremont, CA, USA
| | | | | |
Collapse
|
37
|
Zhang XN, Meng QH, Zeng M, Hou HR. Decoding olfactory EEG signals for different odor stimuli identification using wavelet-spatial domain feature. J Neurosci Methods 2021; 363:109355. [PMID: 34506866 DOI: 10.1016/j.jneumeth.2021.109355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/11/2021] [Accepted: 09/05/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Decoding olfactory-induced electroencephalography (olfactory EEG) signals has gained significant attention in recent years, owing to its potential applications in several fields, such as disease diagnosis, multimedia applications, and brain-computer interaction (BCI). Extracting discriminative features from olfactory EEG signals with low spatial resolution and poor signal-to-noise ratio is vital but challenging for improving decoding accuracy. NEW METHODS By combining discrete wavelet transform (DWT) with one-versus-rest common spatial pattern (OVR-CSP), we develop a novel feature, named wavelet-spatial domain feature (WSDF), to decode the olfactory EEG signals. First, DWT is employed on EEG signals for multilevel wavelet decomposition. Next, the DWT coefficients obtained at a specific level are subjected to OVR-CSP for spatial filtering. Correspondingly, the variance is extracted to generate a discriminative feature set, labeled as WSDF. RESULTS To verify the effectiveness of WSDF, a classification of olfactory EEG signals was conducted on two data sets, i.e., a public EEG dataset 'Odor Pleasantness Perception Dataset (OPPD)', and a self-collected dataset, by using support vector machine (SVM) trained based on different cross-validation methods. Experimental results showed that on OPPD dataset, the proposed method achieved a best average accuracy of 100% and 94.47% for the eyes-open and eyes-closed conditions, respectively. Moreover, on our own dataset, the proposed method gave a highest average accuracy of 99.50%. COMPARISON WITH EXISTING METHODS Compared with a wide range of EEG features and existing works on the same dataset, our WSDF yielded superior classification performance. CONCLUSIONS The proposed WSDF is a promising candidate for decoding olfactory EEG signals.
Collapse
Affiliation(s)
- Xiao-Nei Zhang
- Institute of Robotics and Autonomous Systems, School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China
| | - Qing-Hao Meng
- Institute of Robotics and Autonomous Systems, School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China
| | - Ming Zeng
- Institute of Robotics and Autonomous Systems, School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.
| | - Hui-Rang Hou
- Institute of Robotics and Autonomous Systems, School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.
| |
Collapse
|
38
|
Iravani B, Arshamian A, Lundqvist M, Kay LM, Wilson DA, Lundström JN. Odor identity can be extracted from the reciprocal connectivity between olfactory bulb and piriform cortex in humans. Neuroimage 2021; 237:118130. [PMID: 33951509 DOI: 10.1016/j.neuroimage.2021.118130] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/15/2021] [Accepted: 04/26/2021] [Indexed: 01/28/2023] Open
Abstract
Neuronal oscillations route external and internal information across brain regions. In the olfactory system, the two central nodes-the olfactory bulb (OB) and the piriform cortex (PC)-communicate with each other via neural oscillations to shape the olfactory percept. Communication between these nodes have been well characterized in non-human animals but less is known about their role in the human olfactory system. Using a recently developed and validated EEG-based method to extract signals from the OB and PC sources, we show in healthy human participants that there is a bottom-up information flow from the OB to the PC in the beta and gamma frequency bands, while top-down information from the PC to the OB is facilitated by delta and theta oscillations. Importantly, we demonstrate that there was enough information to decipher odor identity above chance from the low gamma in the OB-PC oscillatory circuit as early as 100 ms after odor onset. These data further our understanding of the critical role of bidirectional information flow in human sensory systems to produce perception. However, future studies are needed to determine what specific odor information is extracted and communicated in the information exchange.
Collapse
Affiliation(s)
- Behzad Iravani
- Department of Clinical Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
| | - Artin Arshamian
- Department of Clinical Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden; Department of Psychology, Stockholm University, 10691 Stockholm, Sweden
| | - Mikael Lundqvist
- Department of Psychology, Stockholm University, 10691 Stockholm, Sweden
| | - Leslie M Kay
- Department of Psychology and Institute for Mind and Biology, The University of Chicago, Chicago, IL 60637, USA
| | - Donald A Wilson
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Department of Child and Adolescent Psychiatry, New York University Langone Medical School, New York, NY 10016, USA
| | - Johan N Lundström
- Department of Clinical Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden; Monell Chemical Senses Center, Philadelphia, PA 19104, USA; Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA; Stockholm University Brain Imaging Centre, Stockholm University, 10691 Stockholm, Sweden.
| |
Collapse
|
39
|
Manzini I, Schild D, Di Natale C. Principles of odor coding in vertebrates and artificial chemosensory systems. Physiol Rev 2021; 102:61-154. [PMID: 34254835 DOI: 10.1152/physrev.00036.2020] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The biological olfactory system is the sensory system responsible for the detection of the chemical composition of the environment. Several attempts to mimic biological olfactory systems have led to various artificial olfactory systems using different technical approaches. Here we provide a parallel description of biological olfactory systems and their technical counterparts. We start with a presentation of the input to the systems, the stimuli, and treat the interface between the external world and the environment where receptor neurons or artificial chemosensors reside. We then delineate the functions of receptor neurons and chemosensors as well as their overall I-O relationships. Up to this point, our account of the systems goes along similar lines. The next processing steps differ considerably: while in biology the processing step following the receptor neurons is the "integration" and "processing" of receptor neuron outputs in the olfactory bulb, this step has various realizations in electronic noses. For a long period of time, the signal processing stages beyond the olfactory bulb, i.e., the higher olfactory centers were little studied. Only recently there has been a marked growth of studies tackling the information processing in these centers. In electronic noses, a third stage of processing has virtually never been considered. In this review, we provide an up-to-date overview of the current knowledge of both fields and, for the first time, attempt to tie them together. We hope it will be a breeding ground for better information, communication, and data exchange between very related but so far little connected fields.
Collapse
Affiliation(s)
- Ivan Manzini
- Animal Physiology and Molecular Biomedicine, Justus-Liebig-University Gießen, Gießen, Germany
| | - Detlev Schild
- Institute of Neurophysiology and Cellular Biophysics, University Medical Center, University of Göttingen, Göttingen, Germany
| | - Corrado Di Natale
- Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy
| |
Collapse
|
40
|
Wang J, Li Q, Huang Q, Lv M, Li P, Dai J, Zhou M, Xu J, Zhang F, Gao J. Washed Microbiota Transplantation Accelerates the Recovery of Abnormal Changes by Light-Induced Stress in Tree Shrews. Front Cell Infect Microbiol 2021; 11:685019. [PMID: 34249778 PMCID: PMC8262326 DOI: 10.3389/fcimb.2021.685019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/21/2021] [Indexed: 12/12/2022] Open
Abstract
The gut and brain interact constantly in a complex fashion. Its intricacy and intrigue is progressively being revealed in the study of the "gut-brain axis". Among many factors, abnormal light exposure is a potential powerful stressor, which is becoming ever more pervasive in our modern society. However, little is known about how stress, induced by staying up late by light, affects the gut-brain axis. We addressed this question by extending the normal circadian light for four hours at night in fifteen male tree shrews to simulate the pattern of staying up late in humans. The behavior, biochemical tests, microbiota dynamics, and brain structure of tree shrews were evaluated. The simple prolongation of light in the environment resulted in substantial changes of body weight loss, behavioral differences, total sleep time reduction, and an increased level of urine cortisol. These alterations were rescued by the treatment of either ketamine or washed microbiota transplantation (WMT). Importantly, the sustainability of WMT effect was better than that of ketamine. Magnetic Resonance Imaging analysis indicated that ketamine acted on the hippocampus and thalamus, and WMT mainly affected the piriform cortex and lateral geniculate nucleus. In conclusion, long-term light stimulation could change the behaviors, composition of gut microbiota and brain structure in tree shrews. Targeting microbiota thus certainly holds promise as a treatment for neuropsychiatric disorders, including but not limited to stress-related diseases.
Collapse
Affiliation(s)
- Jing Wang
- Department of Neurobiology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China.,Visual Cognition Laboratory, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Qianqian Li
- Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China.,Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing, China
| | - Qi Huang
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Meng Lv
- Animal Core Facility of Nanjing Medical University, Nanjing Medical University, Nanjing, China
| | - Pan Li
- Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China.,Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing, China
| | - Jing Dai
- Department of Neurobiology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Minjie Zhou
- Department of Neurobiology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Jialu Xu
- Department of Neurobiology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China
| | - Faming Zhang
- Medical Center for Digestive Diseases, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China.,Key Lab of Holistic Integrative Enterology, Nanjing Medical University, Nanjing, China
| | - Jun Gao
- Department of Neurobiology, School of Basic Medical Sciences, Nanjing Medical University, Nanjing, China.,Department of Rehabilitation Medicine, Jiangsu Shengze Hospital Affiliated to Nanjing Medical University, Nanjing Medical University, Nanjing, China
| |
Collapse
|
41
|
Gotow N, Hoshi A, Kobayakawa T. Background stimulus delays detection of target stimulus in a familiar odor-odor combination. Sci Rep 2021; 11:11987. [PMID: 34099772 PMCID: PMC8184818 DOI: 10.1038/s41598-021-91295-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 05/19/2021] [Indexed: 11/30/2022] Open
Abstract
Familiarity of odor–odor combinations is enhanced through food intake in daily life. As familiarity increases, the perceptual boundary between two odors may become ambiguous; therefore, we hypothesized that exposure to one odor would delay detection of the other in a high-familiarity combination but not in a low-familiarity combination. To test this hypothesis, we measured the speed of odor detection using two types of background stimuli (black tea odor and odorless air) and two types of target stimuli (lemon odor and almond odor). For Japanese participants, the combination of black tea and lemon odor has high familiarity, whereas the combination of black tea and almond odors has low familiarity. Reaction time for detection of target stimulus was measured by inserting a pulsed target stimulus into the flow of the background stimulus (i.e., replacing the background stimulus with the target stimulus for a short time). Reaction time for detection of lemon odor was significantly longer under the black tea odor condition than under the odorless air condition. Reaction time for detection of almond odor was similar between the black tea odor and odorless air conditions. These results are in line with the hypothesis that familiarity of an odor–odor combination affects odor detection speed. Further investigations are required to reach more robust conclusions.
Collapse
Affiliation(s)
- Naomi Gotow
- Human Informatics Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan
| | - Ayaka Hoshi
- KIRIN Central Research Institute, Research & Development Division, Kirin Holdings Company, Limited, 1-13-5, Fukuura, Kanazawa, Yokohama, Kanagawa, 236-0004, Japan
| | - Tatsu Kobayakawa
- Human Informatics Interaction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8566, Japan.
| |
Collapse
|
42
|
Donoshita Y, Choi US, Ban H, Kida I. Assessment of olfactory information in the human brain using 7-Tesla functional magnetic resonance imaging. Neuroimage 2021; 236:118212. [PMID: 34082117 DOI: 10.1016/j.neuroimage.2021.118212] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 05/13/2021] [Accepted: 05/25/2021] [Indexed: 10/21/2022] Open
Abstract
Olfaction could prove to be an early marker of neurodegenerative diseases, including Alzheimer's and Parkinson's diseases. To use olfaction for disease diagnosis, elucidating the standard olfactory functions in healthy humans is necessary. However, the olfactory function in the human brain is less frequently assessed because of methodological difficulties associated with olfactory-related cerebral areas. Using ultra-high fields (UHF), functional magnetic resonance imaging (fMRI) with high spatial resolution and sensitivity may allow for the measurement of activation in the cerebral areas. This study aimed to apply 7-Tesla fMRI to assess olfactory function in the human brain by exposing individuals to four different odorants for 8 s. We found that olfactory stimulation mainly activated the piriform and orbitofrontal cortex in addition to the amygdala. Among these regions, univariate fMRI analysis indicated that subjective odor intensity significantly correlated with the averaged fMRI signals in the piriform cortex but not with subjective hedonic tone in any region. In contrast, multivariate fMRI analysis showed that subjective hedonic tone could be discriminated from the fMRI response patterns in the posterior orbitofrontal cortex. Thus, the piriform cortex is mainly associated with subjective odor intensity, whereas the posterior orbitofrontal cortex are involved in the discrimination of the subjective hedonic tone of the odorant. UHF-fMRI may be useful for assessing olfactory function in the human brain.
Collapse
Affiliation(s)
- Yuka Donoshita
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita, Osaka 565-0871, Japan; Daikin Industries, Ltd., Settsu, Osaka 566-8585, Japan
| | - Uk-Su Choi
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita, Osaka 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hiroshi Ban
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita, Osaka 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Ikuhiro Kida
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita, Osaka 565-0871, Japan; Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan.
| |
Collapse
|
43
|
Midroit M, Chalençon L, Renier N, Milton A, Thevenet M, Sacquet J, Breton M, Forest J, Noury N, Richard M, Raineteau O, Ferdenzi C, Fournel A, Wesson DW, Bensafi M, Didier A, Mandairon N. Neural processing of the reward value of pleasant odorants. Curr Biol 2021; 31:1592-1605.e9. [PMID: 33607032 DOI: 10.1016/j.cub.2021.01.066] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/07/2021] [Accepted: 01/19/2021] [Indexed: 02/07/2023]
Abstract
Pleasant odorants are represented in the posterior olfactory bulb (pOB) in mice. How does this hedonic information generate odor-motivated behaviors? Using optogenetics, we report here that stimulating the representation of pleasant odorants in a sensory structure, the pOB, can be rewarding, self-motivating, and is accompanied by ventral tegmental area activation. To explore the underlying neural circuitry downstream of the olfactory bulb (OB), we use 3D high-resolution imaging and optogenetics and determine that the pOB preferentially projects to the olfactory tubercle, whose increased activity is related to odorant attraction. We further show that attractive odorants act as reinforcers in dopamine-dependent place preference learning. Finally, we extend those findings to humans, who exhibit place preference learning and an increase BOLD signal in the olfactory tubercle in response to attractive odorants. Thus, strong and persistent attraction induced by some odorants is due to a direct gateway from the pOB to the reward system.
Collapse
Affiliation(s)
- Maëllie Midroit
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Laura Chalençon
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Nicolas Renier
- Sorbonne Universités, Paris Brain Institute, ICM, Inserm, CNRS, Paris, France
| | - Adrianna Milton
- Department of Neurosciences, Case Western Reserve University, 2109 Adelbert Road, Cleveland, OH 44106, USA
| | - Marc Thevenet
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Joëlle Sacquet
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Marine Breton
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Jérémy Forest
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Norbert Noury
- CNRS, UMR5270, Institute Nanotechnology Lyon, Biomedical Sensors Group, University of Lyon 1, Villeurbanne 69621, France
| | - Marion Richard
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Olivier Raineteau
- University Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Camille Ferdenzi
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Arnaud Fournel
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Daniel W Wesson
- Department of Pharmacology & Therapeutics, University of Florida, 1200 Newell Drive, Gainesville, FL 32610, USA
| | - Moustafa Bensafi
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Anne Didier
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France
| | - Nathalie Mandairon
- CNRS, UMR 5292, INSERM, U1028, Lyon Neuroscience Research Center, Neuroplasticity and Neuropathology of Olfactory Perception Team, Lyon 69000, France; University Lyon, Lyon, 69000, France; University Lyon 1, Villeurbanne 69000, France.
| |
Collapse
|
44
|
Laing DG, Epps A, Jinks AL. Chemosensory Loss during a Traumatic Brain Injury Suggests a Central Pathway for the Rehabilitation of Anosmia. Chem Senses 2021; 46:6225237. [PMID: 33893484 DOI: 10.1093/chemse/bjab016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Currently, no method has been developed for rehabilitating olfaction in anosmic patients following a traumatic brain injury (TBI). Here a method for rehabilitation is described which is based on a recent finding that the human posterior pyriform cortex (PPC) generates predictive odor "search images" in advance of an encounter with an olfactory stimulus. The search image enhances perceptual sensitivity and allows the odor it represents to be identified without input occurring from the olfactory receptors or bulbs. Furthermore, based on the finding here that anosmics with a TBI often have normal trigeminal and gustatory function, it is proposed that normality in these chemosensory systems may indicate that key cortical regions including the PPC are intact in anosmics and capable of processing olfactory information. In addition, the results of chemosensory tests of the olfactory, gustatory, and intranasal trigeminal systems of 18 patients with a TBI are given that identify which patients would most likely benefit from the rehabilitation procedure.
Collapse
Affiliation(s)
- David G Laing
- Discipline of Paediatrics, School of Women's and Children's Health, University of NSW Medicine, Level 3, Sydney Children's Hospital, High Street, Randwick, NSW 2031, Australia
| | - Adrienne Epps
- Rehab2Kids, Sydney Children's Hospital, High Street, Randwick, NSW 2031, Australia
| | - Anthony L Jinks
- School of Psychology, Western Sydney University, Kingswood Campus, Second Avenue, NSW 2747, Australia
| |
Collapse
|
45
|
Avery JA. Against gustotopic representation in the human brain: There is no Cartesian Restaurant. CURRENT OPINION IN PHYSIOLOGY 2021; 20:23-28. [PMID: 33521413 PMCID: PMC7839947 DOI: 10.1016/j.cophys.2021.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The insular cortex is still one of the least understood cortical regions in the human brain. This review will highlight research on taste quality representation within the human insular cortex. Much of the controversy surrounding this topic is based in the ongoing debate over different theories of peripheral taste coding. When translated to the study of gustatory cortex, this has generated a distinct set of theoretical models, namely the topographic (or 'gustotopic') and population coding models of taste organization. Recent investigations into this topic have employed high-resolution functional neuroimaging methods and multivariate analytic approaches to examine taste quality coding in the human brain. Collectively, these recent studies do not support the topographic model of taste quality representation, but rather one where taste quality is represented by distributed patterns of activation within gustatory regions of the insula.
Collapse
Affiliation(s)
- Jason A Avery
- Laboratory of Brain and Cognition, National Institute of Mental Health, Bethesda, MD, United States, 20892
| |
Collapse
|
46
|
Kudryavitskaya E, Marom E, Shani-Narkiss H, Pash D, Mizrahi A. Flexible categorization in the mouse olfactory bulb. Curr Biol 2021; 31:1616-1631.e4. [DOI: 10.1016/j.cub.2021.01.063] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 12/11/2020] [Accepted: 01/19/2021] [Indexed: 11/30/2022]
|
47
|
Zhou G, Olofsson JK, Koubeissi MZ, Menelaou G, Rosenow J, Schuele SU, Xu P, Voss JL, Lane G, Zelano C. Human hippocampal connectivity is stronger in olfaction than other sensory systems. Prog Neurobiol 2021; 201:102027. [PMID: 33640412 DOI: 10.1016/j.pneurobio.2021.102027] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/20/2021] [Accepted: 02/21/2021] [Indexed: 12/17/2022]
Abstract
During mammalian evolution, primate neocortex expanded, shifting hippocampal functional networks away from primary sensory cortices, towards association cortices. Reflecting this rerouting, human resting hippocampal functional networks preferentially include higher association cortices, while those in rodents retained primary sensory cortices. Research on human visual, auditory and somatosensory systems shows evidence of this rerouting. Olfaction, however, is unique among sensory systems in its relative structural conservation throughout mammalian evolution, and it is unknown whether human primary olfactory cortex was subject to the same rerouting. We combined functional neuroimaging and intracranial electrophysiology to directly compare hippocampal functional networks across human sensory systems. We show that human primary olfactory cortex-including the anterior olfactory nucleus, olfactory tubercle and piriform cortex-has stronger functional connectivity with hippocampal networks at rest, compared to other sensory systems. This suggests that unlike other sensory systems, olfactory-hippocampal connectivity may have been retained in mammalian evolution. We further show that olfactory-hippocampal connectivity oscillates with nasal breathing. Our findings suggest olfaction might provide insight into how memory and cognition depend on hippocampal interactions.
Collapse
Affiliation(s)
- Guangyu Zhou
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| | - Jonas K Olofsson
- Department of Psychology, Stockholm University, Stockholm, Sweden; Emotional Brain Institute, Nathan S. Kline Institute, Orangeburg, NY, USA; Department of Child and Adolescent Psychiatry, New York University School of Medicine, New York, NY, USA
| | | | | | - Joshua Rosenow
- Department of Neurosurgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Stephan U Schuele
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Pengfei Xu
- Beijing Key Laboratory of Applied Experimental Psychology, Faculty of Psychology, Beijing Normal University, Beijing, China; Center for Neuroimaging, Shenzhen Institute of Neuroscience, Shenzhen, China; Guangdong-Hong Kong-Macao Greater Bay Area Research Institute for Neuroscience and Neurotechnologies, Kwun Tong, Hong Kong, China
| | - Joel L Voss
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Department of Medical Social Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Gregory Lane
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Christina Zelano
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| |
Collapse
|
48
|
Individual odor hedonic perception is coded in temporal joint network activity. Neuroimage 2021; 229:117782. [PMID: 33497777 DOI: 10.1016/j.neuroimage.2021.117782] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 12/22/2022] Open
Abstract
INTRO The human sense of smell is highly individual and characterized by a strong variability in the perception and evaluation of olfactory stimuli, depending on cultural imprint and current physiological conditions. Since this individual perspective has often been neglected in fMRI studies on olfactory hedonic coding, this study focuses on the neuronal activity and connectivity patterns resulting from subject-specific olfactory stimulation. METHODS Thirty-one normosmic participants took part in a fMRI block designed paradigm consisting of three olfactory stimulation sessions. The most pleasant and unpleasant odors were individually specified during a pre-test for each participant and validated in the main experiment. Mean activation and functional connectivity analysis focusing on the right and left piriform cortex were performed for the predefined olfactory regions-of-interest (ROIs) and compared between the three olfactory conditions. RESULTS Individual unpleasant olfactory stimulation as compared to pleasant or neutral did not alter mean BOLD activation in the predefined olfactory ROIs but led to a change in connectivity pattern in the right piriform cortex. CONCLUSION Our data suggests that the individual pleasantness of odors is not detectable by average BOLD magnitude changes in primary or secondary olfactory brain areas, but reflected in temporal patterns of joint activation that create a network between the right piriform cortex, the left insular cortex, the orbitofrontal cortex, and the precentral gyrus. This network may serve the evolutionary defense mechanism of olfaction by preparing goal-directed action.
Collapse
|
49
|
Mantel M, Roy JM, Bensafi M. Accounting for Subjectivity in Experimental Research on Human Olfaction. Chem Senses 2021; 46:6065098. [PMID: 33403395 DOI: 10.1093/chemse/bjaa082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Although olfaction is a modality with great interindividual perceptual disparities, its subjective dimension has been let aside in modern research, in line with the overall neglect of consciousness in experimental psychology. However, following the renewed interest for the neural bases of consciousness, some methodological leads have been proposed to include subjectivity in experimental protocols. Here, we argue that adapting such methods to the field of olfaction will allow to rigorously acquire subjective reports, and we present several ways to do so. This will improve the understanding of diversity in odor perception and its underlying neural mechanisms.
Collapse
Affiliation(s)
- Marylou Mantel
- Lyon Neuroscience Research Center, CNRS UMR INSERM, CH Le Vinatier Bat, Bron, Cedex, France.,Ecole Normale Supérieure de Lyon, Parvis Descartes, Lyon, France
| | - Jean-Michel Roy
- Ecole Normale Supérieure de Lyon, Parvis Descartes, Lyon, France
| | - Moustafa Bensafi
- Lyon Neuroscience Research Center, CNRS UMR INSERM, CH Le Vinatier Bat, Bron, Cedex, France
| |
Collapse
|
50
|
Jraissati Y, Deroy O. Categorizing Smells: A Localist Approach. Cogn Sci 2021; 45:e12930. [PMID: 33389758 DOI: 10.1111/cogs.12930] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 11/16/2020] [Accepted: 11/19/2020] [Indexed: 11/30/2022]
Abstract
Humans are poorer at identifying smells and communicating about them, compared to other sensory domains. They also cannot easily organize odor sensations in a general conceptual space, where geometric distance could represent how similar or different all odors are. These two generalities are more or less accepted by psychologists, and they are often seen as connected: If there is no conceptual space for odors, then olfactory identification should indeed be poor. We propose here an important revision to this conclusion: We believe that the claim that there is no odor space is true only if by odor space, one means a conceptual space representing all possible odor sensations, in the paradigmatic sense used for instance for color. However, in a less paradigmatic sense, local conceptual spaces representing a given subset of odors do exist. Thus the absence of a global odor space does not warrant the conclusion that there is no olfactory conceptual map at all. Here we show how a localist account provides a new interpretation of experts and cross-cultural categorization studies: Rather than being exceptions to the poor olfactory identification and communication usually seen elsewhere, experts and cross-cultural categorization are here taken to corroborate the existence of local conceptual spaces.
Collapse
Affiliation(s)
- Yasmina Jraissati
- Ronin Institute.,Department of Philosophy, American University of Beirut
| | - Ophelia Deroy
- Faculty of Philosophy, Ludwig Maximilian University.,Munich Centre for Neuroscience, Ludwig Maximilian University.,Institute of Philosophy, School of Advanced Study, University of London
| |
Collapse
|