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Basile BM, Waters SJ, Murray EA. What does preferential viewing tell us about the neurobiology of recognition memory? Trends Neurosci 2024; 47:326-337. [PMID: 38582659 PMCID: PMC11096050 DOI: 10.1016/j.tins.2024.03.003] [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: 11/01/2023] [Revised: 02/09/2024] [Accepted: 03/14/2024] [Indexed: 04/08/2024]
Abstract
The two tests most widely used in nonhuman primates to assess the neurobiology of recognition memory produce conflicting results. Preferential viewing tests (e.g., visual paired comparison) produce robust impairments following hippocampal lesions, whereas matching tests (e.g., delayed nonmatching-to-sample) often show complete sparing. Here, we review the data, the proposed explanations for this discrepancy, and then critically evaluate those explanations. The most likely explanation is that preferential viewing tests are not a process-pure assessment of recognition memory, but also test elements of novelty-seeking, habituation, and motivation. These confounds likely explain the conflicting results. Thus, we propose that memory researchers should prefer explicit matching tests and readers interested in the neural substrates of recognition memory should give explicit matching tests greater interpretive weight.
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Affiliation(s)
| | - Spencer J Waters
- Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, USA; Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, Bethesda, MD, USA
| | - Elisabeth A Murray
- Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, Bethesda, MD, USA.
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2
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López-Pérez SJ, Ureña-Guerrero ME, Bañuelos-Pineda J. An extract of Hibiscus sabdariffa improves short-term memory in rats with experimental diabetic hyperglycemia. Nutr Neurosci 2024:1-11. [PMID: 38193451 DOI: 10.1080/1028415x.2023.2301166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
BACKGROUND Calyxes of Hibiscus sabdariffa (Hs) contain anthocyanins, that normalize blood glucose levels (BGL) in diabetic patients. Diabetes also causes memory alterations, which could hypothetically decrease with the consumption of Hs. OBJECTIVES To investigate the effect of dietary supplementation with a Hs extract on working memory and BGL in rats. METHODS Diabetic hyperglycemia (DHG) was induced with streptozotocin (STZ, 55 mg/kg i.p.) in Wistar rats. After 72 h DHG was confirmed, and the consumption of Hs extract began (50 mg/Kg/day). BGL and body weight (BW) were measured at 10, 20 and 30 days after DHG induction in controls and treated animals. Learning and short-term memory were evaluated after 30 days with Novel Object Recognition Test (NOR) and Barnes Maze (BM). The gross hippocampal structure was histologically analyzed. RESULTS STZ-treated animals presented low BW and persistent DHG (BGL <300 mg/dL). Diabetic animals consuming the Hs extract had a dual response: some showed BGL comparable to controls, while others had levels comparable to diabetic animals not consuming extract. Diabetic animals that consumed the Hs extract had a better performance in NOR and BM than the diabetic animals not consuming the extract. At the histological level, hippocampal morphological differences were observed between diabetic animals that consumed the extract and those that did not. DISCUSSION The Hs extract used here could be a good co-adjuvant in the treatment of DHG, aimed at mitigating memory deficits and high BGL. These beneficial effects could be attributed to the anthocyanin content in the extract.
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Affiliation(s)
- Silvia J López-Pérez
- Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias (CUCBA), Universidad de Guadalajara. Zapopan, Jalisco, México
| | - Mónica E Ureña-Guerrero
- Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias (CUCBA), Universidad de Guadalajara. Zapopan, Jalisco, México
| | - Jacinto Bañuelos-Pineda
- Departamento de Medicina Veterinaria, Centro Universitario de Ciencias Biológicas y Agropecuarias (CUCBA), Universidad de Guadalajara. Zapopan, Jalisco, México
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Waters SJ, Basile BM, Murray EA. Reevaluating the role of the hippocampus in memory: A meta-analysis of neurotoxic lesion studies in nonhuman primates. Hippocampus 2023; 33:787-807. [PMID: 36649170 DOI: 10.1002/hipo.23499] [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: 01/21/2022] [Revised: 12/21/2022] [Accepted: 12/28/2022] [Indexed: 01/18/2023]
Abstract
The hippocampus and perirhinal cortex are both broadly implicated in memory; nevertheless, their relative contributions to visual item recognition and location memory remain disputed. Neuropsychological studies in nonhuman primates that examine memory function after selective damage to medial temporal lobe structures report various levels of memory impairment-ranging from minor deficits to profound amnesia. The discrepancies in published findings have complicated efforts to determine the exact magnitude of visual item recognition and location memory impairments following damage to the hippocampus and/or perirhinal cortex. To provide the most accurate estimate to date of the overall effect size, we use meta-analytic techniques on data aggregated from 26 publications that assessed visual item recognition and/or location memory in nonhuman primates with and without selective neurotoxic lesions of the hippocampus or perirhinal cortex. We estimated the overall effect size, evaluated the relation between lesion extent and effect size, and investigated factors that may account for between-study variation. Grouping studies by lesion target and testing method, separate meta-analyses were conducted. One meta-analysis indicated that impairments on tests of visual item recognition were larger after lesions of perirhinal cortex than after lesions of the hippocampus. A separate meta-analysis showed that performance on tests of location memory was severely impaired by lesions of the hippocampus. For the most part, meta-regressions indicated that greater impairment corresponds with greater lesion extent; paradoxically, however, more extensive hippocampal lesions predicted smaller impairments on tests of visual item recognition. We conclude the perirhinal cortex makes a larger contribution than the hippocampus to visual item recognition, and the hippocampus predominately contributes to spatial navigation.
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Affiliation(s)
- Spencer J Waters
- Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Bethesda, Maryland, USA.,Interdisciplinary Program in Neuroscience, Georgetown University, Washington, District of Columbia, USA
| | - Benjamin M Basile
- Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Bethesda, Maryland, USA.,Department of Psychology, Dickinson College, Carlisle, Pennsylvania, USA
| | - Elisabeth A Murray
- Section on the Neurobiology of Learning and Memory, Laboratory of Neuropsychology, National Institute of Mental Health, NIH, Bethesda, Maryland, USA
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Vogt ME, Riesgo VR, Flanigan KAS, Willing JG. Housing Environment Affects Pubertal Onset, Anxiety-like Behavior, and Object Interaction in Male and Female Long Evans Rats. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2022; 61:241-247. [PMID: 35512999 PMCID: PMC9137291 DOI: 10.30802/aalas-jaalas-21-000119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 12/30/2021] [Accepted: 03/28/2022] [Indexed: 06/14/2023]
Abstract
Rodents used for research can be humanely housed in a variety of ways. As such, a vast number of different housing environments are used, but are often not described in research publications. However, many elements of housing environments, including bedding, diet, water bottles, and cage material, can expose rodents to natural and synthetic compounds that can have lasting effects on the body, brain, and behavior. Some environmental items contain endocrine-disrupting compounds (EDCs), which can affect many commonly assessed physiological and behavioral endpoints in rodents. Here, we compare the effects of 2 commonly used housing environments for male and female Long Evans rats on body weight, pubertal onset, and a battery of behavioral tests measuring activity, anxiety-like behavior, and cognition. One standard environment was comparatively high in EDCs (standard rodent chow, plastic cages, plastic water bottles, and corncob bedding), while the other was a relatively low-EDC environment (phytoestrogen-free chow, polysulfone cages, glass water bottles, and wood-chip bedding). As compared with the Standard group, rats raised in the Low-EDC environment reached puberty earlier, displayed less anxiety-like behavior in the elevated plus maze and open field test, and showed less overall object exploration in the novel object recognition task. These effects occurred only if rats had been raised in these conditions since conception. An acute change from one environment to the other in adulthood did not yield these same effects. These results provide further evidence for the effects of common housing environments on development and behavior and highlight the importance of reporting environmental conditions in the literature to promote reproducibility in research using animal subjects.
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Affiliation(s)
- Meghan E Vogt
- Department of Psychology: Neural and Cognitive Sciences Program, Bowling Green State University, Bowling Green, Ohio
| | - Victoria R Riesgo
- Department of Psychology: Neural and Cognitive Sciences Program, Bowling Green State University, Bowling Green, Ohio
| | - Kaylyn A S Flanigan
- Department of Psychology: Neural and Cognitive Sciences Program, Bowling Green State University, Bowling Green, Ohio
| | - Jari G Willing
- Department of Psychology: Neural and Cognitive Sciences Program, Bowling Green State University, Bowling Green, Ohio;,
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Sayahi Z, Komaki A, Saidi Jam M, Karimi SA, Raoufi S, Mardani P, Naderishahab M, Sarihi A, Mirnajafi-Zadeh J. Effect of ramosetron, a 5-HT 3 receptor antagonist on the severity of seizures and memory impairment in electrical amygdala kindled rats. J Physiol Sci 2022; 72:1. [PMID: 35034601 PMCID: PMC10717980 DOI: 10.1186/s12576-022-00825-5] [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: 03/16/2021] [Accepted: 01/04/2022] [Indexed: 11/10/2022]
Abstract
The entorhinal cortex (EC) plays a pivotal role in epileptogenesis and seizures. EC expresses high density of serotonergic receptors, especially 5-HT3 receptors. Cognitive impairment is common among people with epilepsy. The present study investigated the role of 5-HT3 receptor on the severity of seizures and learning and memory impairment by electrical kindling of amygdala in rats. The amygdala kindling was conducted in a chronic kindling manner in male Wistar rats. In fully kindled animals, ramosetron (as a potent and selective 5-HT3 receptor antagonist) was microinjected unilaterally (ad doses of 1, 10 or 100 µg/0.5 µl) into the EC 5 min before the novel object recognition (NOR) and Y-maze tests or kindling stimulations. Applying ramosetron at the concentration of 100 μg/0.5 µl (but not at 1 and 10 µg/0.5 µl) reduced afterdischarge (AD) duration and increased stage 4 latency in the kindled rats. Moreover, the obtained data from the NOR test showed that treatment by ramosetron (10 and 100 µg/0.5 µl) increased the discrimination index in the fully kindled animals. Microinjection of ramosetron (10 and 100 µg/0.5 µl) in fully kindled animals reversed the kindling induced changes in the percentage of spontaneous alternation in Y-maze task. The findings demonstrated an anticonvulsant role for a selective 5-HT3 receptor antagonist microinjected into the EC, therefore, suggesting an excitatory role for the EC 5-HT3 receptors in the amygdala kindling model of epilepsy. This anticonvulsive effect was accompanied with a restoring effect on cognitive behavior in NOR and Y-maze tests.
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Affiliation(s)
- Zeynab Sayahi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
| | - Alireza Komaki
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
- Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Masoud Saidi Jam
- Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Asaad Karimi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
- Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Safoura Raoufi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
| | - Parastoo Mardani
- Department of Biology, Faculty of Sciences, Payame Noor University, Sanandaj, Iran
| | - Marzieh Naderishahab
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran
| | - Abdolrahman Sarihi
- Neurophysiology Research Center, Hamadan University of Medical Sciences, Shahid Fahmideh Street, 6517838736, Hamadan, Iran.
- Department of Neuroscience, School of Sciences and Advanced Technology in Medicine, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, 1411713116, Tehran, Iran.
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Abstract
There are currently a number of theories of rodent hippocampal function. They fall into two major groups that differ in the role they impute to space in hippocampal information processing. On one hand, the cognitive map theory sees space as crucial and central, with other types of nonspatial information embedded in a primary spatial framework. On the other hand, most other theories see the function of the hippocampal formation as broader, treating all types of information as equivalent and concentrating on the processes carried out irrespective of the specific material being represented, stored, and manipulated. One crucial difference, therefore, is the extent to which theories see hippocampal pyramidal cells as representing nonspatial information independently of a spatial framework. Studies have reported the existence of single hippocampal unit responses to nonspatial stimuli, both to simple sensory inputs as well as to more complex stimuli such as objects, conspecifics, rewards, and time, and these findings been interpreted as evidence in favor of a broader hippocampal function. Alternatively, these nonspatial responses might actually be feature-in-place signals where the spatial nature of the response has been masked by the fact that the objects or features were only presented in one location or one spatial context. In this article, we argue that when tested in multiple locations, the hippocampal response to nonspatial stimuli is almost invariably dependent on the animal's location. Looked at collectively, the data provide strong support for the cognitive map theory.
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Affiliation(s)
- John O'Keefe
- Sainsbury Wellcome Centre and Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Julija Krupic
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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Wooden JI, Spinetta MJ, Nguyen T, O'Leary CI, Leasure JL. A Sensitive Homecage-Based Novel Object Recognition Task for Rodents. Front Behav Neurosci 2021; 15:680042. [PMID: 34177480 PMCID: PMC8232937 DOI: 10.3389/fnbeh.2021.680042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/14/2021] [Indexed: 11/25/2022] Open
Abstract
The recognition of novel objects is a common cognitive test for rodents, but current paradigms have limitations, such as low sensitivity, possible odor confounds and stress due to being performed outside of the homecage. We have developed a paradigm that takes place in the homecage and utilizes four stimuli per trial, to increase sensitivity. Odor confounds are eliminated because stimuli consist of inexpensive, machined wooden beads purchased in bulk, so each experimental animal has its own set of stimuli. This paradigm consists of three steps. In Step 1, the sampling phase, animals freely explore familiar objects (FO). Novel Objects (NO1 and NO2) are soiled with bedding from the homecage, to acquire odor cues identical to those of the FO. Steps 2 and 3 are test phases. Herein we report results of this paradigm from neurologically intact adult rats and mice of both sexes. Identical procedures were used for both species, except that the stimuli used for the mice were smaller. As expected in Step 2 (NO1 test phase), male and female rats and mice explored NO1 significantly more than FO. In Step 3 (NO2 test phase), rats of both sexes demonstrated a preference for NO2, while this was seen only in female mice. These results indicate robust novelty recognition during Steps 2 and 3 in rats. In mice, this was reliably seen only in Step 2, indicating that Step 3 was difficult for them under the given parameters. This paradigm provides flexibility in that length of the sampling phase, and the delay between test and sampling phases can be adjusted, to tailor task difficulty to the model being tested. In sum, this novel object recognition test is simple to perform, requires no expensive supplies or equipment, is conducted in the homecage (reducing stress), eliminates odor confounds, utilizes 4 stimuli to increase sensitivity, can be performed in both rats and mice, and is highly flexible, as sampling phase and the delay between steps can be adjusted to tailor task difficulty. Collectively, these results indicate that this paradigm can be used to quantify novel object recognition across sex and species.
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Affiliation(s)
- Jessica I Wooden
- Department of Psychology, University of Houston, Houston, TX, United States
| | - Michael J Spinetta
- Department of Psychology, Seattle University, Seattle, WA, United States
| | - Teresa Nguyen
- Department of Psychology, University of Houston, Houston, TX, United States
| | - Charles I O'Leary
- Department of Psychology, Seattle University, Seattle, WA, United States
| | - J Leigh Leasure
- Department of Psychology, University of Houston, Houston, TX, United States.,Department of Biology and Biochemistry, University of Houston, Houston, TX, United States
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Yoo DY, Jung HY, Kim W, Hahn KR, Kwon HJ, Nam SM, Chung JY, Yoon YS, Kim DW, Hwang IK. Entacapone Treatment Modulates Hippocampal Proteins Related to Synaptic Vehicle Trafficking. Cells 2020; 9:cells9122712. [PMID: 33352833 PMCID: PMC7765944 DOI: 10.3390/cells9122712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 11/29/2022] Open
Abstract
Entacapone, a reversible inhibitor of catechol-O-methyl transferase, is used for patients in Parkinson’s disease because it increases the bioavailability and effectiveness of levodopa. In the present study, we observed that entacapone increases novel object recognition and neuroblasts in the hippocampus. In the present study, two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry were performed to compare the abundance profiles of proteins expressed in the hippocampus after entacapone treatment in mice. Results of 2-DE, MALDI-TOF mass spectrometry, and subsequent proteomic analysis revealed an altered protein expression profile in the hippocampus after entacapone treatment. Based on proteomic analysis, 556 spots were paired during the image analysis of 2-DE gels and 76 proteins were significantly changed more than two-fold among identified proteins. Proteomic analysis indicated that treatment with entacapone induced expressional changes in proteins involved in synaptic transmission, cellular processes, cellular signaling, the regulation of cytoskeletal structure, energy metabolism, and various subcellular enzymatic reactions. In particular, entacapone significantly increased proteins related to synaptic trafficking and plasticity, such as dynamin 1, synapsin I, and Munc18-1. Immunohistochemical staining showed the localization of the proteins, and western blot confirmed the significant increases in dynamin I (203.5% of control) in the hippocampus as well as synapsin I (254.0% of control) and Munc18-1 (167.1% of control) in the synaptic vesicle fraction of hippocampus after entacapone treatment. These results suggest that entacapone can enhance hippocampal synaptic trafficking and plasticity against various neurological diseases related to hippocampal dysfunction.
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Affiliation(s)
- Dae Young Yoo
- Department of Anatomy and Cell Biology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea; (D.Y.Y.); (H.Y.J.); (W.K.); (K.R.H.); (Y.S.Y.)
- Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan 31151, Korea
| | - Hyo Young Jung
- Department of Anatomy and Cell Biology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea; (D.Y.Y.); (H.Y.J.); (W.K.); (K.R.H.); (Y.S.Y.)
| | - Woosuk Kim
- Department of Anatomy and Cell Biology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea; (D.Y.Y.); (H.Y.J.); (W.K.); (K.R.H.); (Y.S.Y.)
- Department of Biomedical Sciences, Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Korea
| | - Kyu Ri Hahn
- Department of Anatomy and Cell Biology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea; (D.Y.Y.); (H.Y.J.); (W.K.); (K.R.H.); (Y.S.Y.)
| | - Hyun Jung Kwon
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung 25457, Korea;
| | - Sung Min Nam
- Department of Anatomy, School of Medicine and Institute for Environmental Science, Wonkwang University, Iksan 54538, Korea;
| | - Jin Young Chung
- Department of Veterinary Internal Medicine and Geriatrics, College of Veterinary Medicine, Kangwon National University, Chuncheon 24341, Korea;
| | - Yeo Sung Yoon
- Department of Anatomy and Cell Biology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea; (D.Y.Y.); (H.Y.J.); (W.K.); (K.R.H.); (Y.S.Y.)
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung 25457, Korea;
- Correspondence: (D.W.K.); (I.K.H.)
| | - In Koo Hwang
- Department of Anatomy and Cell Biology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea; (D.Y.Y.); (H.Y.J.); (W.K.); (K.R.H.); (Y.S.Y.)
- Correspondence: (D.W.K.); (I.K.H.)
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Buatois A, Gerlai R. Elemental and Configural Associative Learning in Spatial Tasks: Could Zebrafish be Used to Advance Our Knowledge? Front Behav Neurosci 2020; 14:570704. [PMID: 33390911 PMCID: PMC7773606 DOI: 10.3389/fnbeh.2020.570704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 11/26/2020] [Indexed: 12/13/2022] Open
Abstract
Spatial learning and memory have been studied for several decades. Analyses of these processes pose fundamental scientific questions but are also relevant from a biomedical perspective. The cellular, synaptic and molecular mechanisms underlying spatial learning have been intensively investigated, yet the behavioral mechanisms/strategies in a spatial task still pose unanswered questions. Spatial learning relies upon configural information about cues in the environment. However, each of these cues can also independently form part of an elemental association with the specific spatial position, and thus spatial tasks may be solved using elemental (single CS and US association) learning. Here, we first briefly review what we know about configural learning from studies with rodents. Subsequently, we discuss the pros and cons of employing a relatively novel laboratory organism, the zebrafish in such studies, providing some examples of methods with which both elemental and configural learning may be explored with this species. Last, we speculate about future research directions focusing on how zebrafish may advance our knowledge. We argue that zebrafish strikes a reasonable compromise between system complexity and practical simplicity and that adding this species to the studies with laboratory rodents will allow us to gain a better understanding of both the evolution of and the mechanisms underlying spatial learning. We conclude that zebrafish research will enhance the translational relevance of our findings.
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Affiliation(s)
- Alexis Buatois
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Robert Gerlai
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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Aggleton JP, Nelson AJD. Distributed interactive brain circuits for object-in-place memory: A place for time? Brain Neurosci Adv 2020; 4:2398212820933471. [PMID: 32954003 PMCID: PMC7479857 DOI: 10.1177/2398212820933471] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 05/15/2020] [Indexed: 12/23/2022] Open
Abstract
Rodents will spontaneously learn the location of an individual object, an
ability captured by the object-in-place test. This review considers
the network of structures supporting this behavioural test, as well as
some potential confounds that may affect interpretation. A
hierarchical approach is adopted, as we first consider those brain
regions necessary for two simpler, ‘precursor’ tests (object
recognition and object location). It is evident that performing the
object-in-place test requires an array of areas additional to those
required for object recognition or object location. These additional
areas include the rodent medial prefrontal cortex and two thalamic
nuclei (nucleus reuniens and the medial dorsal nucleus), both densely
interconnected with prefrontal areas. Consequently, despite the need
for object and location information to be integrated for the
object-in-place test, for example, via the hippocampus, other
contributions are necessary. These contributions stem from how
object-in-place is a test of associative recognition, as none of the
individual elements in the test phase are novel. Parallels between the
structures required for object-in-place and for recency
discriminations, along with a re-examination of the demands of the
object-in-place test, signal the integration of temporal information
within what is usually regarded as a spatial-object test.
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Affiliation(s)
- John P Aggleton
- School of Psychology, Cardiff University, Cardiff, Wales, UK
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