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Munch AS, Amat-Foraster M, Agerskov C, Bastlund JF, Herrik KF, Richter U. Sub-anesthetic doses of ketamine increase single cell entrainment in the rat auditory cortex during auditory steady-state response. J Psychopharmacol 2023; 37:822-835. [PMID: 37165655 DOI: 10.1177/02698811231164231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
BACKGROUND Understanding the effects of the N-methyl-D-aspartate receptor (NMDA-R) antagonist ketamine on brain function is of considerable interest due to the discovery of its fast-acting antidepressant properties. It is well known that gamma oscillations are increased when ketamine is administered to rodents and humans, and increases in the auditory steady-state response (ASSR) have also been observed. AIMS To elucidate the cellular substrate of the increase in network activity and synchrony observed by sub-anesthetic doses of ketamine, the aim was to investigate spike timing and regularity and determine how this is affected by the animal's motor state. METHODS Single unit activity and local field potentials from the auditory cortex of awake, freely moving rats were recorded with microelectrode arrays during an ASSR paradigm. RESULTS Ketamine administration yielded a significant increase in ASSR power and phase locking, both significantly modulated by motor activity. Before drug administration, putative fast-spiking interneurons (FSIs) were significantly more entrained to the stimulus than putative pyramidal neurons (PYRs). The degree of entrainment significantly increased at lower doses of ketamine (3 and 10 mg/kg for FSIs, 10 mg/kg for PYRs). At the highest dose (30 mg/kg), a strong increase in tonic firing of PYRs was observed. CONCLUSIONS These findings suggest an involvement of FSIs in the increased network synchrony and provide a possible cellular explanation for the well-documented effects of ketamine-induced increase in power and synchronicity during ASSR. The results support the importance to evaluate different motor states separately for more translational preclinical research.
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Affiliation(s)
- Anders Sonne Munch
- Brain Circuit and Function, Lundbeck & University of Copenhagen, Kobenhavn, Denmark
| | | | - Claus Agerskov
- Pathology, Circuits and Symptoms, Lundbeck, Valby, Denmark
| | | | | | - Ulrike Richter
- Pathology, Circuits and Symptoms, Lundbeck, Valby, Denmark
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2
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Pendry RJ, Quigley LD, Volk LJ, Pfeiffer BE. A novel, lightweight drive implant for chronic tetrode recordings in juvenile mice. bioRxiv 2023:2023.01.04.522760. [PMID: 36711560 PMCID: PMC9881909 DOI: 10.1101/2023.01.04.522760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
SHORT ABSTRACT We describe a novel micro-drive design, surgical implantation procedure, and post-surgery recovery strategy that allows for chronic field and single-unit recordings from up to sixteen brain regions simultaneously in juvenile and adolescent mice across a critical developmental window from p20 to p60 and beyond. LONG ABSTRACT In vivo electrophysiology provides unparalleled insight into sub-second-level circuit dynamics of the intact brain and represents a method of particular importance for studying mouse models of human neuro-psychiatric disorders. However, such methods often require large cranial implants which cannot be used in mice at early developmental timepoints. As such, virtually no studies of in vivo physiology have been performed in freely behaving infant or juvenile mice, despite the fact that a better understanding of neurological development in this critical window is likely to provide unique insights into age-dependent developmental disorders such as autism or schizophrenia. Here, we describe a novel micro-drive design, surgical implantation procedure, and post-surgery recovery strategy that allows for chronic field and single-unit recordings from up to sixteen brain regions simultaneously in mice as they age from postnatal day 20 (p20) to postnatal day 60 (p60) and beyond, a time window roughly corresponding to human ages 2-years-old through adult. The number of recording electrodes and final recording sites can be easily modified and expanded, allowing flexible experimental control of in vivo monitoring of behavior- or disease-relevant brain regions across development.
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Affiliation(s)
- Robert J Pendry
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX,Neuroscience Graduate Program, UT Southwestern Medical Center, Dallas, TX
| | - Lilyana D Quigley
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX,Neuroscience Graduate Program, UT Southwestern Medical Center, Dallas, TX
| | - Lenora J Volk
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX,O’Donnell Brain Institute, UT Southwestern Medical Center, Dallas, TX,Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX
| | - Brad E Pfeiffer
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX,O’Donnell Brain Institute, UT Southwestern Medical Center, Dallas, TX
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3
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Zaldivar D, Koyano KW, Ye FQ, Godlove DC, Park SH, Russ BE, Bhik-Ghanie R, Leopold DA. Brain-wide functional connectivity of face patch neurons during rest. Proc Natl Acad Sci U S A 2022; 119:e2206559119. [PMID: 36044550 DOI: 10.1073/pnas.2206559119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In resting state functional magnetic resonance imaging (fMRI), areas showing coherent hemodynamic fluctuations across the brain are operationally defined to be functionally connected. However, it is unknown how the activity of single units residing within a voxel contributes to this network structure. Here we demonstrate a shared but restricted pattern of functional connectivity among neighboring neurons residing in functionally defined face patches. Unexpectedly, such neurons also exhibited a prominent inverse correlation with thalamic structures and brainstem neuromodulatory centers. Single unit maps differed from analogous maps obtained with local field potentials and seed-based fMRI. These findings suggest that during rest, individual cortical neurons have a restricted set of functional connections, which is governed in part by anatomical projections and in part by neuromodulation. The brain is a highly organized, dynamic system whose network architecture is often assessed through resting functional magnetic resonance imaging (fMRI) functional connectivity. The functional interactions between brain areas, including those observed during rest, are assumed to stem from the collective influence of action potentials carried by long-range neural projections. However, the contribution of individual neurons to brain-wide functional connectivity has not been systematically assessed. Here we developed a method to concurrently measure and compare the spiking activity of local neurons with fMRI signals measured across the brain during rest. We recorded spontaneous activity from neural populations in cortical face patches in the macaque during fMRI scanning sessions. Individual cells exhibited prominent, bilateral coupling with fMRI fluctuations in a restricted set of cortical areas inside and outside the face patch network, partially matching the pattern of known anatomical projections. Within each face patch population, a subset of neurons was positively coupled with the face patch network and another was negatively coupled. The same cells showed inverse correlations with distinct subcortical structures, most notably the lateral geniculate nucleus and brainstem neuromodulatory centers. Corresponding connectivity maps derived from fMRI seeds and local field potentials differed from the single unit maps, particularly in subcortical areas. Together, the results demonstrate that the spiking fluctuations of neurons are selectively coupled with discrete brain regions, with the coupling governed in part by anatomical network connections and in part by indirect neuromodulatory pathways.
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4
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Erez Y, Kadohisa M, Petrov P, Sigala N, Buckley MJ, Kusunoki M, Duncan J. Integrated neural dynamics for behavioural decisions and attentional competition in the prefrontal cortex. Eur J Neurosci 2022; 56:4393-4410. [PMID: 35781352 DOI: 10.1111/ejn.15757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 11/27/2022]
Abstract
In the behaving monkey, complex neural dynamics in the prefrontal cortex contribute to context-dependent decisions and attentional competition. We used demixed principal component analysis to track prefrontal activity dynamics in a cued target detection task. In this task, the animal combined identity of a visual object with a prior instruction cue to determine a target/nontarget decision. From population activity, we extracted principal components for each task feature and examined their time course and sensitivity to stimulus and task variations. For displays containing a single choice object in left or right hemifield, object identity, cue identity and decision were all encoded in population activity, with different dynamics and lateralisation. Object information peaked at 100-200 ms from display onset and was largely confined to the contralateral hemisphere. Cue information was weaker and present even prior to display onset. Integrating information from cue and object, decision information arose more slowly and was bilateral. Individual neurons contributed independently to coding of the three task features. The analysis was then extended to displays with a target in one hemifield and a competing distractor in the other. In this case, the data suggest that each hemisphere initially encoded the identity of the contralateral object. The distractor representation was then rapidly suppressed, with the final target decision again encoded bilaterally. The results show how information is coded along task-related dimensions while competition is resolved and suggest how information flows within and across frontal lobes to implement a learned behavioural decision.
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Affiliation(s)
- Yaara Erez
- Faculty of Engineering, Bar-Ilan University, Ramat-Gan, Israel
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
- Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Mikiko Kadohisa
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
| | - Philippe Petrov
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Natasha Sigala
- Brighton and Sussex Medical School, Brighton, UK
- Sackler Center for Consciousness Science, University of Sussex, Brighton, UK
| | - Mark J Buckley
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Makoto Kusunoki
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
| | - John Duncan
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK
- Department of Experimental Psychology, University of Oxford, Oxford, UK
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5
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Zaback M, Tiwari E, Krupka AJ, Marchionne F, Negro F, Lemay MA, Thompson CK. Toward Assessing the Functional Connectivity of Spinal Neurons. Front Neural Circuits 2022; 16:839521. [PMID: 35310548 PMCID: PMC8927546 DOI: 10.3389/fncir.2022.839521] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/28/2022] [Indexed: 12/14/2022] Open
Abstract
Spinal interneurons play a critical role in motor output. A given interneuron may receive convergent input from several different sensory modalities and descending centers and relay this information to just as many targets. Therefore, there is a critical need to quantify populations of spinal interneurons simultaneously. Here, we quantify the functional connectivity of spinal neurons through the concurrent recording of populations of lumbar interneurons and hindlimb motor units in the in vivo cat model during activation of either the ipsilateral sural nerve or contralateral tibial nerve. Two microelectrode arrays were placed into lamina VII, one at L3 and a second at L6/7, while an electrode array was placed on the surface of the exposed muscle. Stimulation of tibial and sural nerves elicited similar changes in the discharge rate of both interneurons and motor units. However, these same neurons showed highly significant differences in prevalence and magnitude of correlated activity underlying these two forms of afferent drive. Activation of the ipsilateral sural nerve resulted in highly correlated activity, particularly at the caudal array. In contrast, the contralateral tibial nerve resulted in less, but more widespread correlated activity at both arrays. These data suggest that the ipsilateral sural nerve has dense projections onto caudal lumbar spinal neurons, while contralateral tibial nerve has a sparse pattern of projections.
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Affiliation(s)
- Martin Zaback
- Department of Health and Rehabilitation Sciences, College of Public Health, Temple University, Philadelphia, PA, United States,Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States
| | - Ekta Tiwari
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States,School of Engineering, Brown University, Providence, RI, United States
| | - Alexander J. Krupka
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States,Department of Biology, DeSales University, Center Valley, PA, United States
| | - Francesca Marchionne
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States
| | - Francesco Negro
- Department of Clinical and Experimental Sciences, Universita degli Studi di Brescia, Brescia, Italy
| | - Michel A. Lemay
- Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, United States
| | - Christopher K. Thompson
- Department of Health and Rehabilitation Sciences, College of Public Health, Temple University, Philadelphia, PA, United States,Shriner’s Hospital for Children, Philadelphia, PA, United States,*Correspondence: Christopher K. Thompson,
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6
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Roux F, Parish G, Chelvarajah R, Rollings DT, Sawlani V, Hamer H, Gollwitzer S, Kreiselmeyer G, ter Wal MJ, Kolibius L, Staresina BP, Wimber M, Self MW, Hanslmayr S. Oscillations support short latency co-firing of neurons during human episodic memory formation. eLife 2022; 11:78109. [PMID: 36448671 PMCID: PMC9731574 DOI: 10.7554/elife.78109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 11/29/2022] [Indexed: 12/05/2022] Open
Abstract
Theta and gamma oscillations in the medial temporal lobe are suggested to play a critical role for human memory formation via establishing synchrony in neural assemblies. Arguably, such synchrony facilitates efficient information transfer between neurons and enhances synaptic plasticity, both of which benefit episodic memory formation. However, to date little evidence exists from humans that would provide direct evidence for such a specific role of theta and gamma oscillations for episodic memory formation. Here, we investigate how oscillations shape the temporal structure of neural firing during memory formation in the medial temporal lobe. We measured neural firing and local field potentials in human epilepsy patients via micro-wire electrode recordings to analyze whether brain oscillations are related to co-incidences of firing between neurons during successful and unsuccessful encoding of episodic memories. The results show that phase-coupling of neurons to faster theta and gamma oscillations correlates with co-firing at short latencies (~20-30 ms) and occurs during successful memory formation. Phase-coupling at slower oscillations in these same frequency bands, in contrast, correlates with longer co-firing latencies and occurs during memory failure. Thus, our findings suggest that neural oscillations play a role for the synchronization of neural firing in the medial temporal lobe during the encoding of episodic memories.
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Affiliation(s)
- Frédéric Roux
- School of Psychology, Centre for Human Brain Health, University of BirminghamBirminghamUnited Kingdom
| | - George Parish
- School of Psychology, Centre for Human Brain Health, University of BirminghamBirminghamUnited Kingdom
| | - Ramesh Chelvarajah
- School of Psychology, Centre for Human Brain Health, University of BirminghamBirminghamUnited Kingdom,Complex Epilepsy and Surgery Service, Neuroscience Department, Queen Elizabeth Hospital BirminghamBirminghamUnited Kingdom
| | - David T Rollings
- Complex Epilepsy and Surgery Service, Neuroscience Department, Queen Elizabeth Hospital BirminghamBirminghamUnited Kingdom
| | - Vijay Sawlani
- School of Psychology, Centre for Human Brain Health, University of BirminghamBirminghamUnited Kingdom,Complex Epilepsy and Surgery Service, Neuroscience Department, Queen Elizabeth Hospital BirminghamBirminghamUnited Kingdom
| | - Hajo Hamer
- Epilepsy Center, Department of Neurology, University Hospital ErlangenErlangenGermany
| | - Stephanie Gollwitzer
- Epilepsy Center, Department of Neurology, University Hospital ErlangenErlangenGermany
| | - Gernot Kreiselmeyer
- Epilepsy Center, Department of Neurology, University Hospital ErlangenErlangenGermany
| | - Marije J ter Wal
- School of Psychology, Centre for Human Brain Health, University of BirminghamBirminghamUnited Kingdom
| | - Luca Kolibius
- School of Psychology and Neuroscience, Centre for Cognitive Neuroimaging, University of GlasgowGlasgowUnited Kingdom
| | - Bernhard P Staresina
- School of Psychology, Centre for Human Brain Health, University of BirminghamBirminghamUnited Kingdom,Department of Experimental Psychology, University of OxfordOxfordUnited Kingdom
| | - Maria Wimber
- School of Psychology, Centre for Human Brain Health, University of BirminghamBirminghamUnited Kingdom,School of Psychology and Neuroscience, Centre for Cognitive Neuroimaging, University of GlasgowGlasgowUnited Kingdom
| | - Matthew W Self
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, an institute of the Royal Netherlands Academy of Art and SciencesAmsterdamNetherlands
| | - Simon Hanslmayr
- School of Psychology, Centre for Human Brain Health, University of BirminghamBirminghamUnited Kingdom,School of Psychology and Neuroscience, Centre for Cognitive Neuroimaging, University of GlasgowGlasgowUnited Kingdom
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7
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Müller Ewald VA, Kim J, Farley SJ, Freeman JH, LaLumiere RT. Theta oscillations in rat infralimbic cortex are associated with the inhibition of cocaine seeking during extinction. Addict Biol 2022; 27:e13106. [PMID: 34672059 PMCID: PMC8922975 DOI: 10.1111/adb.13106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/21/2021] [Accepted: 09/24/2021] [Indexed: 11/27/2022]
Abstract
Infralimbic cortical (IL) manipulations indicate that this region mediates extinction learning and suppresses cocaine seeking following cocaine self‐administration. However, little work has recorded IL activity during the inhibition of cocaine seeking due to the difficulty of determining precisely when cocaine‐seeking behaviour is inhibited within a cocaine‐seeking session. The present study used in vivo electrophysiology to examine IL activity across extinction as well as during cocaine self‐administration and reinstatement. Sprague–Dawley rats underwent 6‐h access cocaine self‐administration in which the response lever was available during discrete signalled trials, a procedure which allowed for the comparison between epochs of cocaine seeking versus the inhibition thereof. Subsequently, rats underwent extinction and cocaine‐primed reinstatement using the same procedure. Results indicate that theta rhythms (4–10 Hz) dominated IL local‐field potential (LFP) activity during all experimental stages. During extinction, theta power fluctuated significantly surrounding the lever press and was lower when rats engaged in cocaine seeking versus when they withheld from doing so. These patterns of oscillatory activity differed from self‐administration and reinstatement stages. Single‐unit analyses indicate heterogeneity of IL unit responses, supporting the idea that multiple neuronal subpopulations exist within the IL and promote the expression of different and even opposing cocaine‐seeking behaviours. Together, these results are consistent with the idea that aggregate synaptic and single‐unit activity in the IL represent the engagement of the IL in action monitoring to promote adaptive behaviour in accordance with task contingencies and reveal critical insights into the relationship between IL activity and the inhibition of cocaine seeking.
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Affiliation(s)
- Victória A. Müller Ewald
- Department of Psychiatry University of Iowa Iowa City Iowa USA
- Interdisciplinary Neuroscience Program University of Iowa Iowa City Iowa USA
| | - Jangjin Kim
- Interdisciplinary Neuroscience Program University of Iowa Iowa City Iowa USA
- Department of Psychological and Brain Sciences University of Iowa Iowa City Iowa USA
| | - Sean J. Farley
- Interdisciplinary Neuroscience Program University of Iowa Iowa City Iowa USA
- Department of Psychological and Brain Sciences University of Iowa Iowa City Iowa USA
| | - John H. Freeman
- Interdisciplinary Neuroscience Program University of Iowa Iowa City Iowa USA
- Department of Psychological and Brain Sciences University of Iowa Iowa City Iowa USA
- Iowa Neuroscience Institute University of Iowa Iowa City Iowa USA
| | - Ryan T. LaLumiere
- Interdisciplinary Neuroscience Program University of Iowa Iowa City Iowa USA
- Department of Psychological and Brain Sciences University of Iowa Iowa City Iowa USA
- Iowa Neuroscience Institute University of Iowa Iowa City Iowa USA
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8
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Williams B, Del Rosario J, Muzzu T, Peelman K, Coletta S, Bichler EK, Speed A, Meyer-Baese L, Saleem AB, Haider B. Spatial modulation of dark versus bright stimulus responses in the mouse visual system. Curr Biol 2021; 31:4172-4179.e6. [PMID: 34314675 PMCID: PMC8478832 DOI: 10.1016/j.cub.2021.06.094] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 05/20/2021] [Accepted: 06/30/2021] [Indexed: 01/06/2023]
Abstract
A fundamental task of the visual system is to respond to both increases and decreases of luminance with action potentials (ON and OFF responses1-4). OFF responses are stronger, faster, and more salient than ON responses in primary visual cortex (V1) of both cats5,6 and primates,7,8 but in ferrets9 and mice,10 ON responses can be stronger, weaker,11 or balanced12 in comparison to OFF responses. These discrepancies could arise from differences in species, experimental techniques, or stimulus properties, particularly retinotopic location in the visual field, as has been speculated;9 however, the role of retinotopy for ON/OFF dominance has not been systematically tested across multiple scales of neural activity within species. Here, we measured OFF versus ON responses across large portions of visual space with silicon probe and whole-cell patch-clamp recordings in mouse V1 and lateral geniculate nucleus (LGN). We found that OFF responses dominated in the central visual field, whereas ON and OFF responses were more balanced in the periphery. These findings were consistent across local field potential (LFP), spikes, and subthreshold membrane potential in V1, and were aligned with spatial biases in ON and OFF responses in LGN. Our findings reveal that retinotopy may provide a common organizing principle for spatial modulation of OFF versus ON processing in mammalian visual systems.
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Affiliation(s)
- Brice Williams
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Joseph Del Rosario
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Tomaso Muzzu
- UCL Institute of Behavioural Neuroscience, Department of Experimental Psychology, University College London, London WC1H 0AP, UK
| | - Kayla Peelman
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Stefano Coletta
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Edyta K Bichler
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Anderson Speed
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Lisa Meyer-Baese
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA
| | - Aman B Saleem
- UCL Institute of Behavioural Neuroscience, Department of Experimental Psychology, University College London, London WC1H 0AP, UK
| | - Bilal Haider
- Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA, USA.
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9
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Sakon JJ, Suzuki WA. Neural evidence for recognition of naturalistic videos in monkey hippocampus. Hippocampus 2021; 31:916-932. [PMID: 34021646 DOI: 10.1002/hipo.23335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/26/2021] [Accepted: 04/17/2021] [Indexed: 11/11/2022]
Abstract
The role of the hippocampus in recognition memory has long been a source of debate. Tasks used to study recognition that typically require an explicit probe, where the participant must make a response to prove they remember, yield mixed results on hippocampal involvement. Here, we tasked monkeys to freely view naturalistic videos, and only tested their memory via looking times for two separate novel versus repeat video conditions on each trial. Notably, a large proportion (>30%) of hippocampal neurons differentiated these videos via changes in firing rates time-locked to the duration of their presentation on screen, and not during the delay period between them as would be expected for working memory. Many of these single neurons (>15%) contributed to both retrieval conditions, and differentiated novel from repeat videos across trials with trial-unique content, suggesting they detect familiarity. The majority of neurons contributing to the classifier showed an enhancement in firing rate on repeat compared with novel videos, a pattern which has not previously been shown in hippocampus. These results suggest the hippocampus contributes to recognition memory via familiarity during free-viewing.
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Affiliation(s)
- John J Sakon
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wendy A Suzuki
- Center for Neural Science, New York University, New York, New York, USA
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10
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Chari A, Thornton RC, Tisdall MM, Scott RC. Microelectrode recordings in human epilepsy: a case for clinical translation. Brain Commun 2020; 2:fcaa082. [PMID: 32954332 PMCID: PMC7472902 DOI: 10.1093/braincomms/fcaa082] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 04/21/2020] [Accepted: 04/28/2020] [Indexed: 12/25/2022] Open
Abstract
With their 'all-or-none' action potential responses, single neurons (or units) are accepted as the basic computational unit of the brain. There is extensive animal literature to support the mechanistic importance of studying neuronal firing as a way to understand neuronal microcircuits and brain function. Although most studies have emphasized physiology, there is increasing recognition that studying single units provides novel insight into system-level mechanisms of disease. Microelectrode recordings are becoming more common in humans, paralleling the increasing use of intracranial electroencephalography recordings in the context of presurgical evaluation in focal epilepsy. In addition to single-unit data, microelectrode recordings also record local field potentials and high-frequency oscillations, some of which may be different to that recorded by clinical macroelectrodes. However, microelectrodes are being used almost exclusively in research contexts and there are currently no indications for incorporating microelectrode recordings into routine clinical care. In this review, we summarize the lessons learnt from 65 years of microelectrode recordings in human epilepsy patients. We cover the electrode constructs that can be utilized, principles of how to record and process microelectrode data and insights into ictal dynamics, interictal dynamics and cognition. We end with a critique on the possibilities of incorporating single-unit recordings into clinical care, with a focus on potential clinical indications, each with their specific evidence base and challenges.
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Affiliation(s)
- Aswin Chari
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Neurosurgery, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Rachel C Thornton
- Department of Clinical Neurophysiology, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Martin M Tisdall
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Neurosurgery, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Rodney C Scott
- Developmental Neurosciences, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
- Department of Neurological Sciences, University of Vermont, Burlington, VT 05405, USA
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11
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Wang CH, Monaco JD, Knierim JJ. Hippocampal Place Cells Encode Local Surface-Texture Boundaries. Curr Biol 2020; 30:1397-1409.e7. [PMID: 32109393 DOI: 10.1016/j.cub.2020.01.083] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/21/2019] [Accepted: 01/29/2020] [Indexed: 10/24/2022]
Abstract
The cognitive map is often assumed to be a Euclidean map that isometrically represents the real world (i.e., the Euclidean distance between any two locations in the physical world should be preserved on the cognitive map). However, accumulating evidence suggests that environmental boundaries can distort the mental representations of physical space. For example, the distance between two locations can be remembered as longer than the true physical distance if the locations are separated by a boundary. While this overestimation is observed under different experimental conditions, even when the boundary is formed by flat surface cues, its physiological basis is not well understood. We examined the neural representation of flat surface cue boundaries, and of the space segregated by these boundaries, by recording place cell activity from CA1 and CA3 while rats foraged on a circular track or square platforms with inhomogeneous surface textures. About 40% of the place field edges concentrated near the boundaries on the circular track (significantly above the chance level 33%). Similarly, place field edges were more prevalent near boundaries on the platforms than expected by chance. In both one- and two-dimensional environments, the population vectors of place cell activity changed more abruptly with distance between locations that crossed cue boundaries than between locations within a bounded region. These results show that the locations of surface boundaries were evident as enhanced decorrelations of the neural representations of locations to either side of the boundaries. This enhancement might underlie the cognitive phenomenon of overestimation of distances across boundaries.
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Affiliation(s)
- Chia-Hsuan Wang
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Joseph D Monaco
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - James J Knierim
- Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21218, USA.
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Ulyanova AV, Cottone C, Adam CD, Gagnon KG, Cullen DK, Holtzman T, Jamieson BG, Koch PF, Chen HI, Johnson VE, Wolf JA. Multichannel Silicon Probes for Awake Hippocampal Recordings in Large Animals. Front Neurosci 2019; 13:397. [PMID: 31080400 PMCID: PMC6497800 DOI: 10.3389/fnins.2019.00397] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 04/08/2019] [Indexed: 12/31/2022] Open
Abstract
Decoding laminar information across deep brain structures and cortical regions is necessary in order to understand the neuronal ensembles that represent cognition and memory. Large animal models are essential for translational research due to their gyrencephalic neuroanatomy and significant white matter composition. A lack of long-length probes with appropriate stiffness allowing penetration to deeper structures with minimal damage to the neural interface is one of the major technical limitations to applying the approaches currently utilized in lower order animals to large animals. We therefore tested the performance of multichannel silicon probes of various solutions and designs that were developed specifically for large animal electrophysiology. Neurophysiological signals from dorsal hippocampus were recorded in chronically implanted awake behaving Yucatan pigs. Single units and local field potentials were analyzed to evaluate performance of given silicon probes over time. EDGE-style probes had the highest yields during intra-hippocampal recordings in pigs, making them the most suitable for chronic implantations and awake behavioral experimentation. In addition, the cross-sectional area of silicon probes was found to be a crucial determinant of silicon probe performance over time, potentially due to reduction of damage to the neural interface. Novel 64-channel EDGE-style probes tested acutely produced an optimal single unit separation and a denser sampling of the laminar structure, identifying these research silicon probes as potential candidates for chronic implantations. This study provides an analysis of multichannel silicon probes designed for large animal electrophysiology of deep laminar brain structures, and suggests that current designs are reaching the physical thresholds necessary for long-term (∼1 month) recordings with single-unit resolution.
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Affiliation(s)
- Alexandra V. Ulyanova
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Carlo Cottone
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Christopher D. Adam
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Kimberly G. Gagnon
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - D. Kacy Cullen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
| | | | - Brian G. Jamieson
- Scientific & Biomedical Microsystems, Glen Burnie, MD, United States
| | - Paul F. Koch
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - H. Isaac Chen
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
| | - Victoria E. Johnson
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - John A. Wolf
- Center for Brain Injury and Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States
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Wixted JT, Goldinger SD, Squire LR, Kuhn JR, Papesh MH, Smith KA, Treiman DM, Steinmetz PN. Coding of episodic memory in the human hippocampus. Proc Natl Acad Sci U S A 2018; 115:1093-8. [PMID: 29339476 DOI: 10.1073/pnas.1716443115] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Neurocomputational models have long posited that episodic memories in the human hippocampus are represented by sparse, stimulus-specific neural codes. A concomitant proposal is that when sparse-distributed neural assemblies become active, they suppress the activity of competing neurons (neural sharpening). We investigated episodic memory coding in the hippocampus and amygdala by measuring single-neuron responses from 20 epilepsy patients (12 female) undergoing intracranial monitoring while they completed a continuous recognition memory task. In the left hippocampus, the distribution of single-neuron activity indicated that only a small fraction of neurons exhibited strong responding to a given repeated word and that each repeated word elicited strong responding in a different small fraction of neurons. This finding reflects sparse distributed coding. The remaining large fraction of neurons exhibited a concurrent reduction in firing rates relative to novel words. The observed pattern accords with longstanding predictions that have previously received scant support from single-cell recordings from human hippocampus.
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Aasebø IEJ, Lepperød ME, Stavrinou M, Nøkkevangen S, Einevoll G, Hafting T, Fyhn M. Temporal Processing in the Visual Cortex of the Awake and Anesthetized Rat. eNeuro 2017; 4:ENEURO. [PMID: 28791331 DOI: 10.1523/ENEURO.0059-17.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/16/2017] [Accepted: 07/17/2017] [Indexed: 12/18/2022] Open
Abstract
The activity pattern and temporal dynamics within and between neuron ensembles are essential features of information processing and believed to be profoundly affected by anesthesia. Much of our general understanding of sensory information processing, including computational models aimed at mathematically simulating sensory information processing, rely on parameters derived from recordings conducted on animals under anesthesia. Due to the high variety of neuronal subtypes in the brain, population-based estimates of the impact of anesthesia may conceal unit- or ensemble-specific effects of the transition between states. Using chronically implanted tetrodes into primary visual cortex (V1) of rats, we conducted extracellular recordings of single units and followed the same cell ensembles in the awake and anesthetized states. We found that the transition from wakefulness to anesthesia involves unpredictable changes in temporal response characteristics. The latency of single-unit responses to visual stimulation was delayed in anesthesia, with large individual variations between units. Pair-wise correlations between units increased under anesthesia, indicating more synchronized activity. Further, the units within an ensemble show reproducible temporal activity patterns in response to visual stimuli that is changed between states, suggesting state-dependent sequences of activity. The current dataset, with recordings from the same neural ensembles across states, is well suited for validating and testing computational network models. This can lead to testable predictions, bring a deeper understanding of the experimental findings and improve models of neural information processing. Here, we exemplify such a workflow using a Brunel network model.
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Kornblith S, Quian Quiroga R, Koch C, Fried I, Mormann F. Persistent Single-Neuron Activity during Working Memory in the Human Medial Temporal Lobe. Curr Biol 2017; 27:1026-32. [PMID: 28318972 DOI: 10.1016/j.cub.2017.02.013] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/13/2017] [Accepted: 02/06/2017] [Indexed: 11/22/2022]
Abstract
Working memory is an essential component of human cognition. Persistent activity related to working memory has been reported in many brain areas, including the inferior temporal and prefrontal cortex [1-8]. The medial temporal lobe (MTL) contains "concept cells" that respond invariantly to specific individuals or places whether presented as images, text, or speech [9, 10]. It is unknown, however, whether the MTL also participates in working memory processes. We thus sought to determine whether human MTL neurons respond to images held in working memory. We recorded from patients with chronically intractable epilepsy as they performed a task that required them to remember three or four sequentially presented pictures across a brief delay. 48% of visually selective neurons continued to carry image-specific information after image offset, but most ceased to encode previously presented images after a subsequent presentation of a different image. However, 8% of visually selective neurons encoded previously presented images during a final maintenance period, despite presentation of further images in the intervening interval. Population activity of stimulus-selective neurons predicted behavioral outcome in terms of correct and incorrect responses. These findings indicate that the MTL is part of a brain-wide network for working memory.
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Riceberg JS, Shapiro ML. Orbitofrontal Cortex Signals Expected Outcomes with Predictive Codes When Stable Contingencies Promote the Integration of Reward History. J Neurosci 2017; 37:2010-21. [PMID: 28115481 DOI: 10.1523/JNEUROSCI.2951-16.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 12/08/2016] [Accepted: 12/29/2016] [Indexed: 11/21/2022] Open
Abstract
Memory can inform goal-directed behavior by linking current opportunities to past outcomes. The orbitofrontal cortex (OFC) may guide value-based responses by integrating the history of stimulus-reward associations into expected outcomes, representations of predicted hedonic value and quality. Alternatively, the OFC may rapidly compute flexible "online" reward predictions by associating stimuli with the latest outcome. OFC neurons develop predictive codes when rats learn to associate arbitrary stimuli with outcomes, but the extent to which predictive coding depends on most recent events and the integrated history of rewards is unclear. To investigate how reward history modulates OFC activity, we recorded OFC ensembles as rats performed spatial discriminations that differed only in the number of rewarded trials between goal reversals. The firing rate of single OFC neurons distinguished identical behaviors guided by different goals. When >20 rewarded trials separated goal switches, OFC ensembles developed stable and anticorrelated population vectors that predicted overall choice accuracy and the goal selected in single trials. When <10 rewarded trials separated goal switches, OFC population vectors decorrelated rapidly after each switch, but did not develop anticorrelated firing patterns or predict choice accuracy. The results show that, whereas OFC signals respond rapidly to contingency changes, they predict choices only when reward history is relatively stable, suggesting that consecutive rewarded episodes are needed for OFC computations that integrate reward history into expected outcomes.SIGNIFICANCE STATEMENT Adapting to changing contingencies and making decisions engages the orbitofrontal cortex (OFC). Previous work shows that OFC function can either improve or impair learning depending on reward stability, suggesting that OFC guides behavior optimally when contingencies apply consistently. The mechanisms that link reward history to OFC computations remain obscure. Here, we examined OFC unit activity as rodents performed tasks controlled by contingencies that varied reward history. When contingencies were stable, OFC neurons signaled past, present, and pending events; when contingencies were unstable, past and present coding persisted, but predictive coding diminished. The results suggest that OFC mechanisms require stable contingencies across consecutive episodes to integrate reward history, represent predicted outcomes, and inform goal-directed choices.
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Mormann F, Kornblith S, Cerf M, Ison MJ, Kraskov A, Tran M, Knieling S, Quian Quiroga R, Koch C, Fried I. Scene-selective coding by single neurons in the human parahippocampal cortex. Proc Natl Acad Sci U S A 2017; 114:1153-8. [PMID: 28096381 DOI: 10.1073/pnas.1608159113] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Imaging, electrophysiological, and lesion studies have shown a relationship between the parahippocampal cortex (PHC) and the processing of spatial scenes. Our present knowledge of PHC, however, is restricted to the macroscopic properties and dynamics of bulk tissue; the behavior and selectivity of single parahippocampal neurons remains largely unknown. In this study, we analyzed responses from 630 parahippocampal neurons in 24 neurosurgical patients during visual stimulus presentation. We found a spatially clustered subpopulation of scene-selective units with an associated event-related field potential. These units form a population code that is more distributed for scenes than for other stimulus categories, and less sparse than elsewhere in the medial temporal lobe. Our electrophysiological findings provide insight into how individual units give rise to the population response observed with functional imaging in the parahippocampal place area.
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18
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Abstract
Figure-ground organization and border-ownership assignment are essential for understanding natural scenes. It has been shown that many neurons in the macaque visual cortex signal border-ownership in displays of simple geometric shapes such as squares, but how well these neurons resolve border-ownership in natural scenes is not known. We studied area V2 neurons in behaving macaques with static images of complex natural scenes. We found that about half of the neurons were border-ownership selective for contours in natural scenes, and this selectivity originated from the image context. The border-ownership signals emerged within 70 ms after stimulus onset, only ∼30 ms after response onset. A substantial fraction of neurons were highly consistent across scenes. Thus, the cortical mechanisms of figure-ground organization are fast and efficient even in images of complex natural scenes. Understanding how the brain performs this task so fast remains a challenge.
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Perel S, Sadtler PT, Oby ER, Ryu SI, Tyler-Kabara EC, Batista AP, Chase SM. Single-unit activity, threshold crossings, and local field potentials in motor cortex differentially encode reach kinematics. J Neurophysiol 2015; 114:1500-12. [PMID: 26133797 DOI: 10.1152/jn.00293.2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 06/30/2015] [Indexed: 01/24/2023] Open
Abstract
A diversity of signals can be recorded with extracellular electrodes. It remains unclear whether different signal types convey similar or different information and whether they capture the same or different underlying neural phenomena. Some researchers focus on spiking activity, while others examine local field potentials, and still others posit that these are fundamentally the same signals. We examined the similarities and differences in the information contained in four signal types recorded simultaneously from multielectrode arrays implanted in primary motor cortex: well-isolated action potentials from putative single units, multiunit threshold crossings, and local field potentials (LFPs) at two distinct frequency bands. We quantified the tuning of these signal types to kinematic parameters of reaching movements. We found 1) threshold crossing activity is not a proxy for single-unit activity; 2) when examined on individual electrodes, threshold crossing activity more closely resembles LFP activity at frequencies between 100 and 300 Hz than it does single-unit activity; 3) when examined across multiple electrodes, threshold crossing activity and LFP integrate neural activity at different spatial scales; and 4) LFP power in the "beta band" (between 10 and 40 Hz) is a reliable indicator of movement onset but does not encode kinematic features on an instant-by-instant basis. These results show that the diverse signals recorded from extracellular electrodes provide somewhat distinct and complementary information. It may be that these signal types arise from biological phenomena that are partially distinct. These results also have practical implications for harnessing richer signals to improve brain-machine interface control.
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Affiliation(s)
- Sagi Perel
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania; Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania
| | - Patrick T Sadtler
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania; Systems Neuroscience Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Emily R Oby
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania; Systems Neuroscience Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Stephen I Ryu
- Department of Electrical Engineering, Stanford University, Stanford, California and the Department of Neurosurgery, Palo Alto Medical Foundation, Palo Alto, California
| | | | - Aaron P Batista
- Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania; Systems Neuroscience Institute, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Steven M Chase
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania; Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, Pennsylvania;
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McMahon DB, Russ BE, Elnaiem HD, Kurnikova AI, Leopold DA. Single-unit activity during natural vision: diversity, consistency, and spatial sensitivity among AF face patch neurons. J Neurosci 2015; 35:5537-48. [PMID: 25855170 DOI: 10.1523/JNEUROSCI.3825-14.2015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Several visual areas within the STS of the macaque brain respond strongly to faces and other biological stimuli. Determining the principles that govern neural responses in this region has proven challenging, due in part to the inherently complex stimulus domain of dynamic biological stimuli that are not captured by an easily parameterized stimulus set. Here we investigated neural responses in one fMRI-defined face patch in the anterior fundus (AF) of the STS while macaques freely view complex videos rich with natural social content. Longitudinal single-unit recordings allowed for the accumulation of each neuron's responses to repeated video presentations across sessions. We found that individual neurons, while diverse in their response patterns, were consistently and deterministically driven by the video content. We used principal component analysis to compute a family of eigenneurons, which summarized 24% of the shared population activity in the first two components. We found that the most prominent component of AF activity reflected an interaction between visible body region and scene layout. Close-up shots of faces elicited the strongest neural responses, whereas far away shots of faces or close-up shots of hindquarters elicited weak or inhibitory responses. Sensitivity to the apparent proximity of faces was also observed in gamma band local field potential. This category-selective sensitivity to spatial scale, together with the known exchange of anatomical projections of this area with regions involved in visuospatial analysis, suggests that the AF face patch may be specialized in aspects of face perception that pertain to the layout of a social scene.
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Sugase-Miyamoto Y, Matsumoto N, Ohyama K, Kawano K. Face inversion decreased information about facial identity and expression in face-responsive neurons in macaque area TE. J Neurosci 2014; 34:12457-69. [PMID: 25209284 DOI: 10.1523/JNEUROSCI.0485-14.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
To investigate the effect of face inversion and thatcherization (eye inversion) on temporal processing stages of facial information, single neuron activities in the temporal cortex (area TE) of two rhesus monkeys were recorded. Test stimuli were colored pictures of monkey faces (four with four different expressions), human faces (three with four different expressions), and geometric shapes. Modifications were made in each face-picture, and its four variations were used as stimuli: upright original, inverted original, upright thatcherized, and inverted thatcherized faces. A total of 119 neurons responded to at least one of the upright original facial stimuli. A majority of the neurons (71%) showed activity modulations depending on upright and inverted presentations, and a lesser number of neurons (13%) showed activity modulations depending on original and thatcherized face conditions. In the case of face inversion, information about the fine category (facial identity and expression) decreased, whereas information about the global category (monkey vs human vs shape) was retained for both the original and thatcherized faces. Principal component analysis on the neuronal population responses revealed that the global categorization occurred regardless of the face inversion and that the inverted faces were represented near the upright faces in the principal component analysis space. By contrast, the face inversion decreased the ability to represent human facial identity and monkey facial expression. Thus, the neuronal population represented inverted faces as faces but failed to represent the identity and expression of the inverted faces, indicating that the neuronal representation in area TE cause the perceptual effect of face inversion.
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Panagiotaropoulos TI, Kapoor V, Logothetis NK. Subjective visual perception: from local processing to emergent phenomena of brain activity. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130534. [PMID: 24639588 DOI: 10.1098/rstb.2013.0534] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The combination of electrophysiological recordings with ambiguous visual stimulation made possible the detection of neurons that represent the content of subjective visual perception and perceptual suppression in multiple cortical and subcortical brain regions. These neuronal populations, commonly referred to as the neural correlates of consciousness, are more likely to be found in the temporal and prefrontal cortices as well as the pulvinar, indicating that the content of perceptual awareness is represented with higher fidelity in higher-order association areas of the cortical and thalamic hierarchy, reflecting the outcome of competitive interactions between conflicting sensory information resolved in earlier stages. However, despite the significant insights into conscious perception gained through monitoring the activities of single neurons and small, local populations, the immense functional complexity of the brain arising from correlations in the activity of its constituent parts suggests that local, microscopic activity could only partially reveal the mechanisms involved in perceptual awareness. Rather, the dynamics of functional connectivity patterns on a mesoscopic and macroscopic level could be critical for conscious perception. Understanding these emergent spatio-temporal patterns could be informative not only for the stability of subjective perception but also for spontaneous perceptual transitions suggested to depend either on the dynamics of antagonistic ensembles or on global intrinsic activity fluctuations that may act upon explicit neural representations of sensory stimuli and induce perceptual reorganization. Here, we review the most recent results from local activity recordings and discuss the potential role of effective, correlated interactions during perceptual awareness.
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Affiliation(s)
- Theofanis I Panagiotaropoulos
- Department of Physiology of Cognitive Processes, Max-Planck-Institute for Biological Cybernetics, , Tübingen 72076, Germany
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Ramus SJ, Eichenbaum H. Neural correlates of olfactory recognition memory in the rat orbitofrontal cortex. J Neurosci 2000; 20:8199-208. [PMID: 11050143 PMCID: PMC6772715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
The orbitofrontal cortex (OF) is strongly and reciprocally connected with the perirhinal (PR) and entorhinal areas of the medial temporal lobe and plays an important role in odor recognition memory. This study characterized firing patterns of single neurons in the OF of rats performing a continuous odor-guided delayed nonmatch to sample (DNMS) task. Most OF neurons fired in association with one or more task events, including the initiation of trials, the sampling of odor stimuli, and the consumption of rewards. OF neurons also exhibited sustained odor-selective activity during the memory delay, and a large proportion of OF cells had odor-specific enhanced or suppressed responses on stimulus repetition. Most OF neurons were activated during several task events, or associated with complex behavioral states. The incidence of cells that fired in association with the critical match/non-match judgement was increased as the DNMS rule was learned, and was higher in OF than in perirhinal and entorhinal cortex. Furthermore, the classification of match and nonmatch trials was correlated with accuracy in performance of that judgement. These findings are consistent with the view that OF is a high order association cortex that plays a role both in the memory representations for specific stimuli and in the acquisition and application of task rules.
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Affiliation(s)
- S J Ramus
- Department of Psychology, Boston University, Boston, Massachusetts 02215, USA
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Abstract
Recent studies show that cells in the somatosensory cortex are involved in the short-term retention of tactile information. In addition, some somatosensory cells appear to retain visual information that has been associated with the touch of an object. The presence of such cells suggests that nontactile stimuli associated with touch have access to cortical neuron networks engaged in the haptic sense. Thus, we inferred that somatosensory cells would respond to behaviorally associated visual and tactile stimuli. To test this assumption, single units were recorded from the anterior parietal cortex (Brodmann's areas 3a, 3b, 1, and 2) of monkeys performing a visuo-haptic delay task, which required the memorization of a visual cue for a tactile choice. Most cells responding to that cue responded also to the corresponding object presented for tactile choice. Significant correlations were observed in some cells between their differential reactions to tactile objects and their differential reactions to the associated visual cues. Some cells were recorded in both the cross-modal task and a haptic unimodal task, where the animal had to retain a tactile cue for a tactile choice. In most of these cells, correlations were observed between stimulus-related firing in corresponding cue periods of the two tasks. These findings suggest that cells in somatosensory cortex are the components of neuronal networks representing tactile information. Associated visual stimuli may activate such networks through visuo-haptic associations established by behavioral training.
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Affiliation(s)
- Y D Zhou
- Neuropsychiatric Institute and Brain Research Institute, School of Medicine, University of California, Los Angeles 90024, USA.
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Schoenbaum G, Chiba AA, Gallagher M. Neural encoding in orbitofrontal cortex and basolateral amygdala during olfactory discrimination learning. J Neurosci 1999; 19:1876-84. [PMID: 10024371 PMCID: PMC6782178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/1998] [Revised: 12/15/1998] [Accepted: 12/21/1998] [Indexed: 02/10/2023] Open
Abstract
Orbitofrontal cortex (OFC) is part of a network of structures involved in adaptive behavior and decision making. Interconnections between OFC and basolateral amygdala (ABL) may be critical for encoding the motivational significance of stimuli used to guide behavior. Indeed, much research indicates that neurons in OFC and ABL fire selectively to cues based on their associative significance. In the current study recordings were made in each region within a behavioral paradigm that allowed comparison of the development of associative encoding over the course of learning. In each recording session, rats were presented with novel odors that were informative about the outcome of making a response and had to learn to withhold a response after sampling an odor that signaled a negative outcome. In some cases, reversal training was performed in the same session as the initial learning. Ninety-six of the 328 neurons recorded in OFC and 60 of the 229 neurons recorded in ABL exhibited selective activity during evaluation of the odor cues after learning had occurred. A substantial proportion of those neurons in ABL developed selective activity very early in training, and many reversed selectivity rapidly after reversal. In contrast, those neurons in OFC rarely exhibited selective activity during odor evaluation before the rats reached the criterion for learning, and far fewer reversed selectivity after reversal. The findings support a model in which ABL encodes the motivational significance of cues and OFC uses this information in the selection and execution of an appropriate behavioral strategy.
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Affiliation(s)
- G Schoenbaum
- Department of Psychology, Johns Hopkins University, Baltimore, Maryland 21218, USA
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26
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Young BJ, Otto T, Fox GD, Eichenbaum H. Memory representation within the parahippocampal region. J Neurosci 1997; 17:5183-95. [PMID: 9185556 PMCID: PMC6573311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The activity of 378 single neurons was recorded from areas of the parahippocampal region (PHR), including the perirhinal and lateral entorhinal cortex, as well as the subiculum, in rats performing an odor-guided delayed nonmatching-to-sample task. Nearly every neuron fired in association with some trial event, and every identifiable trial event or behavior was encoded by neuronal activity in the PHR. The greatest proportion of cells was active during odor sampling, and for many cells, activity during this period was odor selective. In addition, odor memory coding was reflected in two general ways. First, a substantial proportion of cells showed odor-selective activity throughout or at the end of the memory delay period. Second, odor-responsive cells showed odor-selective enhancement or suppression of activity during stimulus repetition in the recognition phase of the task. These data, combined with evidence that the PHR is critical for maintaining odor memories in animals performing the same task, indicate that this cortical region mediates the encoding of specific memory cues, maintains stimulus representations, and supports specific match-nonmatch judgments critical to recognition memory. By contrast, hippocampal neurons do not demonstrate evoked or maintained stimulus-specific codings, and hippocampal damage results in little if any decrement in performance on this task. Thus it becomes increasingly clear that the parahippocampal cortex can support recognition memory independent of the distinct memory functions of the hippocampus itself.
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Affiliation(s)
- B J Young
- Department of Psychology, University of Otago, Dunedin, New Zealand
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