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Neuwirth LS, Verrengia MT, Harikinish-Murrary ZI, Orens JE, Lopez OE. Under or Absent Reporting of Light Stimuli in Testing of Anxiety-Like Behaviors in Rodents: The Need for Standardization. Front Mol Neurosci 2022; 15:912146. [PMID: 36061362 PMCID: PMC9428565 DOI: 10.3389/fnmol.2022.912146] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 06/21/2022] [Indexed: 11/17/2022] Open
Abstract
Behavioral neuroscience tests such as the Light/Dark Test, the Open Field Test, the Elevated Plus Maze Test, and the Three Chamber Social Interaction Test have become both essential and widely used behavioral tests for transgenic and pre-clinical models for drug screening and testing. However, as fast as the field has evolved and the contemporaneous involvement of technology, little assessment of the literature has been done to ensure that these behavioral neuroscience tests that are crucial to pre-clinical testing have well-controlled ethological motivation by the use of lighting (i.e., Lux). In the present review paper, N = 420 manuscripts were examined from 2015 to 2019 as a sample set (i.e., n = ~20–22 publications per year) and it was found that only a meager n = 50 publications (i.e., 11.9% of the publications sampled) met the criteria for proper anxiogenic and anxiolytic Lux reported. These findings illustrate a serious concern that behavioral neuroscience papers are not being vetted properly at the journal review level and are being released into the literature and public domain making it difficult to assess the quality of the science being reported. This creates a real need for standardizing the use of Lux in all publications on behavioral neuroscience techniques within the field to ensure that contributions are meaningful, avoid unnecessary duplication, and ultimately would serve to create a more efficient process within the pre-clinical screening/testing for drugs that serve as anxiolytic compounds that would prove more useful than what prior decades of work have produced. It is suggested that improving the standardization of the use and reporting of Lux in behavioral neuroscience tests and the standardization of peer-review processes overseeing the proper documentation of these methodological approaches in manuscripts could serve to advance pre-clinical testing for effective anxiolytic drugs. This report serves to highlight this concern and proposes strategies to proactively remedy them as the field moves forward for decades to come.
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Affiliation(s)
- Lorenz S. Neuwirth
- Department of Psychology, SUNY Old Westbury, Old Westbury, NY, United States
- SUNY Neuroscience Research Institute, SUNY Old Westbury, Old Westbury, NY, United States
- *Correspondence: Lorenz S. Neuwirth
| | - Michael T. Verrengia
- Department of Psychology, SUNY Old Westbury, Old Westbury, NY, United States
- SUNY Neuroscience Research Institute, SUNY Old Westbury, Old Westbury, NY, United States
| | - Zachary I. Harikinish-Murrary
- Department of Psychology, SUNY Old Westbury, Old Westbury, NY, United States
- SUNY Neuroscience Research Institute, SUNY Old Westbury, Old Westbury, NY, United States
| | - Jessica E. Orens
- Department of Psychology, SUNY Old Westbury, Old Westbury, NY, United States
- SUNY Neuroscience Research Institute, SUNY Old Westbury, Old Westbury, NY, United States
| | - Oscar E. Lopez
- Department of Psychology, SUNY Old Westbury, Old Westbury, NY, United States
- SUNY Neuroscience Research Institute, SUNY Old Westbury, Old Westbury, NY, United States
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Bang JY, Sunstrum JK, Garand D, Parfitt GM, Woodin M, Inoue W, Kim J. Hippocampal-hypothalamic circuit controls context-dependent innate defensive responses. eLife 2022; 11:74736. [PMID: 35420543 PMCID: PMC9042231 DOI: 10.7554/elife.74736] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 04/13/2022] [Indexed: 11/13/2022] Open
Abstract
Preys use their memory - where they sensed a predatory threat and whether a safe shelter is nearby - to dynamically control their survival instinct to avoid harm and reach safety. However, it remains unknown which brain regions are involved, and how such top-down control of innate behaviour is implemented at the circuit level. Here, using adult male mice, we show that the anterior hypothalamic nucleus (AHN) is best positioned to control this task as an exclusive target of the hippocampus (HPC) within the medial hypothalamic defense system. Selective optogenetic stimulation and inhibition of hippocampal inputs to the AHN revealed that the HPC→AHN pathway not only mediates the contextual memory of predator threats but also controls the goal-directed escape by transmitting information about the surrounding environment. These results reveal a new mechanism for experience-dependent, top-down control of innate defensive behaviours.
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Affiliation(s)
- Jee Yoon Bang
- Cell and Systems Biology, University of Toronto, Toronto, Canada
| | | | - Danielle Garand
- Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Gustavo Morrone Parfitt
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, United States
| | - Melanie Woodin
- Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Wataru Inoue
- Robarts Research Institute, Western University, London, Canada
| | - Junchul Kim
- Cell and Systems Biology, University of Toronto, Toronto, Canada
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Soares NL, Dorand VAM, Cavalcante HC, Batista KS, de Souza DM, Lima MDS, Salvadori MGDSS, Magnani M, Alves AF, Aquino JDS. Does intermittent fasting associated with aerobic training influence parameters related to the gut-brain axis of Wistar rats? J Affect Disord 2021; 293:176-185. [PMID: 34214787 DOI: 10.1016/j.jad.2021.06.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 06/09/2021] [Accepted: 06/14/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND Intermittent fasting (IF) and aerobic training have demonstrated beneficial effects on intestinal microbiota composition, but little is known about benefits to the brain through the gut-brain axis. The present study aimed to evaluate gut-brain axis parameters in Wistar rats submitted to IF associated or not with aerobic training. METHODS Male rats were evaluated for training performance and then randomized into 4 groups of ten: sedentary control (SC), trained control (TC), sedentary intermittent fasting (SIF), and trained intermittent fasting (TIF), and evaluated during four weeks. RESULTS The adiposity index was similar among the TC (2.15±0.43%), SIF (1.98±0.69%) and TIF (1.86±0.51%) groups, and differed from SC (2.98±0.80%). TIF had lower counts of lactic acid bacteria, while SIF had higher counts of Bifidobacterium and Enterococcus. TIF had the highest amount of formic acid in faeces (44.44±2.40 μmol/g) and lowest amount of succinic acid in the gut (0.38±0.00 μmol/g), while SIF had the highest propionic acid amount in the faeces (802.80±00.33 μmol/g) and the lowest amount of lactic acid in the gut (0.85±0.00 μmol/g). TIF demonstrated a tendency towards an anxiolytic effect and SIF showed potential antidepressant effect. IF caused different brain and intestinal injuries. TIF rats presented a diffuse and intense marking of IL-1β in the hippocampus. CONCLUSION IF and aerobic exercise, associated or not, can modulate parameters related to the gut-brain axis of Wistar rats, and some benefits may be related to the amounts of organic acids.
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Affiliation(s)
- Naís Lira Soares
- Laboratory of Experimental Nutrition, Department of Nutrition, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil; Post Graduate Program in Nutrition Sciences, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Victor Augusto Mathias Dorand
- Laboratory of Experimental Nutrition, Department of Nutrition, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil; Post Graduate Program in Nutrition Sciences, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Hassler Clementino Cavalcante
- Laboratory of Experimental Nutrition, Department of Nutrition, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil; Post Graduate Program in Nutrition Sciences, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Kamila Sabino Batista
- Laboratory of Experimental Nutrition, Department of Nutrition, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil; Post Graduate Program in Nutrition Sciences, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Daniele Melo de Souza
- Laboratory of Experimental Nutrition, Department of Nutrition, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil; Post Graduate Program in Nutrition Sciences, Federal University of Paraíba, João Pessoa, Paraíba, Brazil
| | - Marcos Dos Santos Lima
- Food Technology Laboratory, Department of Food Technology, Federal Institute of the Sertão de Pernambuco (IFPE/ Sertão), Petrolina, Pernambuco, Brazil
| | | | - Marciane Magnani
- Post Graduate Program in Nutrition Sciences, Federal University of Paraíba, João Pessoa, Paraíba, Brazil; Laboratory of Microbial Processes in Food, Department of Food Engineering, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil
| | - Adriano Francisco Alves
- Laboratory of Pathology, Department of Physiology and Pathology, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil
| | - Jailane de Souza Aquino
- Laboratory of Experimental Nutrition, Department of Nutrition, Federal University of Paraíba (UFPB), João Pessoa, Paraíba, Brazil; Post Graduate Program in Nutrition Sciences, Federal University of Paraíba, João Pessoa, Paraíba, Brazil.
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Wirtshafter HS, Wilson MA. Lateral septum as a nexus for mood, motivation, and movement. Neurosci Biobehav Rev 2021; 126:544-559. [PMID: 33848512 DOI: 10.1016/j.neubiorev.2021.03.029] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/18/2021] [Accepted: 03/26/2021] [Indexed: 02/01/2023]
Abstract
The lateral septum (LS) has been implicated in a wide variety of functions, including emotional, motivational, and spatial behavior, and the LS may regulate interactions between the hippocampus and other regions that mediate goal directed behavior. In this review, we suggest that the lateral septum incorporates movement into the evaluation of environmental context with respect to motivation, anxiety, and reward to output an 'integrated movement value signal'. Specifically, hippocampally-derived contextual information may be combined with reinforcement or motivational information in the LS to inform task-relevant decisions. We will discuss how movement is represented in the LS and the literature on the LS's involvement in mood and motivation. We will then connect these results to LS movement-related literature and hypotheses about the role of the lateral septum. We suggest that the LS may communicate a movement-scaled reward signal via changes in place-, movement-, and reward-related firing, and that the LS should be considered a fundamental node of affect and locomotor pathways in the brain.
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Affiliation(s)
- Hannah S Wirtshafter
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA; Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
| | - Matthew A Wilson
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA; Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA; Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
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Bouchatta O, Chaibi I, Baba AA, Ba-M'Hamed S, Bennis M. The effects of Topiramate on isolation-induced aggression: a behavioral and immunohistochemical study in mice. Psychopharmacology (Berl) 2020; 237:2451-2467. [PMID: 32430516 DOI: 10.1007/s00213-020-05546-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 05/05/2020] [Indexed: 10/24/2022]
Abstract
Topiramate, an antiepileptic drug, has been found to be useful for the treatment of aggression in clinical populations. Most preclinical studies related to Topiramate have been focused exclusively on the quantitative aspects of the aggressive behavior between mice. However, there is still limited knowledge regarding the effects of Topiramate on neuronal mechanisms occurring in aggressive mice. The present work aims to understand further the effects of the antiepileptic drug Topiramate on aggressive behaviors, and on the neural correlates underlying such behaviors. To achieve this, we combined the resident-intruder model of isolation-induced aggression in mice with two drug regimens of Topiramate administration (30.0 mg/kg; acute and sub-chronic treatments). Our data showed that both acute and subchronic treatments decreased the intensity of agonistic encounters and reinforced social behavior. By using C-fos immunoreactivity, we investigated the neuronal activation of several brain regions involved in aggressive behavior following subchronic treatment. We found that Topiramate produced activation in several cortical areas and in the lateral septum of resident brain mice compared with their controls. However, Topiramate induced inhibition in the medial nucleus of the amygdala, the dorsomedial nucleus of the periaqueductal gray, and especially in the anterior hypothalamic nucleus. Finally, we performed microinfusion of Topiramate (0.1 and 0.3 mM) into the lateral septum and anterior hypothalamus on offensive behaviors in isolation-induced-aggression paradigm. Interestingly, the microinfusion of Topiramate into the lateral septum has the capacity to alleviate aggressive behavior, without affecting social behavior. However, the microinfusion of Topiramate into the anterior hypothalamus decreased aggressive behavior and slightly reinforced social behavior. Our observations supported that the dose of 0.1 mM of Topiramate appeared more efficacy to treat aggression in adult mice. These pharmacological characteristics may account for Topiramate efficacy on aggressive symptoms in psychiatric patients.
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Affiliation(s)
- Otmane Bouchatta
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences Semlalia, Cadi Ayyad University, Bd. Prince My Abdallah, 40000, Marrakesh, Morocco
| | - Ilias Chaibi
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences Semlalia, Cadi Ayyad University, Bd. Prince My Abdallah, 40000, Marrakesh, Morocco
| | - Abdelfatah Ait Baba
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences Semlalia, Cadi Ayyad University, Bd. Prince My Abdallah, 40000, Marrakesh, Morocco
| | - Saadia Ba-M'Hamed
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences Semlalia, Cadi Ayyad University, Bd. Prince My Abdallah, 40000, Marrakesh, Morocco
| | - Mohamed Bennis
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences Semlalia, Cadi Ayyad University, Bd. Prince My Abdallah, 40000, Marrakesh, Morocco.
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Wilkin MM, Menard JL. Social housing ameliorates the enduring effects of intermittent physical stress during mid-adolescence. Physiol Behav 2020; 214:112750. [DOI: 10.1016/j.physbeh.2019.112750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/02/2019] [Accepted: 11/22/2019] [Indexed: 12/01/2022]
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Deng K, Yang L, Xie J, Tang H, Wu GS, Luo HR. Whole-brain mapping of projection from mouse lateral septal nucleus. Biol Open 2019; 8:bio.043554. [PMID: 31208998 PMCID: PMC6679409 DOI: 10.1242/bio.043554] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The lateral septal nucleus (LS) plays a critical role in emotionality, social behavior and feeding processes, through neural connections with the hippocampus and hypothalamus. We investigated the neural circuits of LS by using herpes simplex virus 1 strain H129 (H129) and pseudorabies virus stain Bartha (PRV). Virus H129 indicates that LS directly projects to some cerebral nuclei (nucleus accumbens, bed nuclei of the stria terminalis and amygdala), part of the hypothalamus (median preoptic, paraventricular, dorsomedial nucleus and lateral area), thalamus (medial habenula, the paraventricular, parataenial and reuniens nuclei, and the medial line nuclei) and the pontine central gray. Then the LS has secondary projections to the CA3 and CA1 field of the hippocampal formation, lateral and medial preoptic area, and the mammillary body. PRV tracing shows that LS are mainly receiving primary inputs from the amygdala, hippocampus, hypothalamic, thalamus, midbrain and hindbrain, and secondary inputs from dorsal and central linear nucleus raphe, the lateral part of the superior central nucleus raphe, the ventral anterior-lateral complex, the intermediodorsal nucleus, the central medial nucleus, the rhomboid nucleus, and the submedial nucleus of the thalamus. The neural circuit data revealed here could help to understand and further research on the function of LS. Summary: We identified the sequence of projections from the lateral septal nucleus by virus tracing and expanded the data on neural circuits, which could help to understand brain function.
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Affiliation(s)
- Ke Deng
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.,University of Chinese Academy of Sciences, Beijing 100039, China
| | - Lu Yang
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Jing Xie
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China.,University of Chinese Academy of Sciences, Beijing 100039, China
| | - He Tang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China
| | - Gui-Sheng Wu
- Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
| | - Huai-Rong Luo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, China .,Key Laboratory for Aging and Regenerative Medicine, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China
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8
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Animals, anxiety, and anxiety disorders: How to measure anxiety in rodents and why. Behav Brain Res 2018; 352:81-93. [DOI: 10.1016/j.bbr.2017.10.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 10/12/2017] [Accepted: 10/14/2017] [Indexed: 12/31/2022]
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Anderson E, McWaters M, McFadden L, Matuszewich L. Defensive burying as an ethological approach to studying anxiety: Influence of juvenile methamphetamine on adult defensive burying behavior in rats. LEARNING AND MOTIVATION 2018. [DOI: 10.1016/j.lmot.2017.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Tao CS, Dhamija P, Booij L, Menard JL. Adversity in early adolescence promotes an enduring anxious phenotype and increases serotonergic innervation of the infralimbic medial prefrontal cortex. Neuroscience 2017; 364:15-27. [PMID: 28893650 DOI: 10.1016/j.neuroscience.2017.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Revised: 08/10/2017] [Accepted: 09/01/2017] [Indexed: 01/22/2023]
Abstract
Stress during early development produces lasting effects on psychopathological outcomes. We analysed the impact of prior intermittent, physical stress (IPS) during early adolescence (PD 22-33) on anxiety-like behaviour of female rats in adulthood. After behavioural testing, we used immunohistochemistry for the 5-HT transporter (SERT) to evaluate 5-HT innervation profiles in the medial prefrontal cortex (mPFC) and ventral hippocampus (VH). Administration of IPS (i.e., water immersion, elevated platform, foot shock) in early adolescence increased rats' anxiety-like behaviour in the elevated plus-maze but had no effects in the shock-probe burying test. In the social interaction test, IPS decreased social interaction, and this effect was driven by selective decreases in the frequency of playfighting with no evident changes in contact and investigative behaviours. Selective stress-induced increases in the density of SERT-ir positive fibres were found in the infralimbic (IL) subregion of the mPFC but not in the cingulate or prelimbic (PL) subregions. IPS in early adolescence did not affect 5-HT innervation profiles in any sub-fields of the VH. Our findings confirm and extend on earlier evidence that stress during early adolescence promotes the emergence of an anxious phenotype and provide novel evidence that these effects are associated with increased 5-HT innervation of the IL mPFC.
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Affiliation(s)
- Cindy S Tao
- Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Prateek Dhamija
- Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Linda Booij
- Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada; Department of Psychology, Concordia University, Montreal, Quebec H4B 1R6, Canada
| | - Janet L Menard
- Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada; Centre for Neuroscience Studies, Queen's University, Kingston, Ontario K7L 3N6, Canada.
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Insights from extracellular matrix studies in the hypothalamus: structural variations of perineuronal nets and discovering a new perifornical area of the anterior hypothalamus. Anat Sci Int 2016; 92:18-24. [PMID: 27714583 DOI: 10.1007/s12565-016-0375-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 09/26/2016] [Indexed: 12/18/2022]
Abstract
The hypothalamus controls metabolism, stress responses, and instinctive behaviors for individual survival and species preservation. Recent studies suggest that hypothalamic neurons retain plasticity throughout adulthood, which enables these neurons to respond to various kinds of changes in environment, nutrients, and fluctuating hormones. One of the mechanisms underlying the regulation of neural plasticity is the formation of a stable extracellular matrix (ECM) structure called perineuronal nets (PNNs). PNNs are large aggregates of heterogeneous ECM molecules such as chondroitin sulfate proteoglycans (CSPGs), hyaluronan, their link proteins, and tenascin-R. PNNs surround the cell body and proximal dendrites of a subset of neurons and limit adult neural plasticity. This review describes the CSPG-based ECM, including the PNNs, with a special focus on the hypothalamus of mice. We first provide an overview of PNNs in terms of their structure, molecular components, and functions, most of which have been demonstrated by extrahypothalamic studies. Second, we show the presence or absence of PNNs within individual hypothalamic regions and then describe non-PNN-formed ECM containing CSPGs that can be observed in particular hypothalamic regions. Finally, we will introduce a newly identified mouse hypothalamic area that we named the perifornical area of the anterior hypothalamus (PeFAH), which contains a cluster of PNN-positive neurons. PeFAH neurons express enkephalin and have bidirectional connections with the lateral septum. The anterior hypothalamus and lateral septum are thought to regulate defensive behaviors; therefore, the PeFAH neurons and PNNs around them could be involved in the regulation of defensive behaviors.
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