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Smith S, Hopp SC. The 5XFAD mouse model of Alzheimer's disease displays age-dependent deficits in habituation to a novel environment. AGING BRAIN 2023; 3:100078. [PMID: 37333676 PMCID: PMC10275951 DOI: 10.1016/j.nbas.2023.100078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 04/26/2023] [Accepted: 05/23/2023] [Indexed: 06/20/2023] Open
Abstract
Habituation is a form of learning characterized by a decrement in responsiveness to a stimulus that is repeated or prolonged. In rodents, habituation to a novel environment is characterized by a decrease in locomotion over time spent in a novel environment. Habituation to a novel environment is dependent on hippocampal function, suggesting that habituation behavior may be a relevant readout for hippocampal-dependent memory deficits that are characteristic of Alzheimer's disease (AD). Current assays that measure hippocampal-dependent memory in preclinical animal models of AD have not accurately predicted the cognitive protection of novel interventions in human trials. Here, we tested whether a behavioral habituation paradigm could detect age-associated changes in a common preclinical mouse model of AD-like amyloid pathology, the 5XFAD mouse. We exposed 5XFAD mice and age-matched wild-type (WT) littermates at 3, 6, and 9Â months of age to a novel environment over two sessions separated by 24Â h and measured their locomotion. WT mice habituated to the novel environment over time, while 5XFAD mice displayed age-dependent deficits in behavioral habituation. We replicated our results using publicly available open field data from 5XFAD and late-onset AD mouse models with TREM2*R47H and APOE4 mutations. Overall, we present behavioral habituation as a potentially sensitive task to assess age-associated behavioral deficits in 5XFAD mice and other mouse models of AD that could be used to test the preclinical efficacy of novel AD therapeutics.
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Affiliation(s)
- Sabrina Smith
- Glenn Biggs Institute for Alzheimerâs and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, USA
| | - Sarah C. Hopp
- Glenn Biggs Institute for Alzheimerâs and Neurodegenerative Diseases, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, USA
- Department of Pharmacology, University of Texas Health Science Center San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, USA
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Huang HW, Zhang XK, Li HY, Wang YG, Jing B, Chen Y, Patel MB, Ely EW, Liu YO, Zhou JX, Lin S, Zhang GB. Higher Grade Glioma Increases the Risk of Postoperative Delirium: Deficient Brain Compensation Might Be a Potential Mechanism of Postoperative Delirium. Front Aging Neurosci 2022; 14:822984. [PMID: 35493935 PMCID: PMC9045131 DOI: 10.3389/fnagi.2022.822984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 03/02/2022] [Indexed: 11/13/2022] Open
Abstract
Objective The brain compensation mechanism in postoperative delirium (POD) has not been reported. We uncovered the mechanism by exploring the association between POD and glioma grades, and the relationship between preoperative brain structural and functional compensation with POD in patients with frontal glioma. Methods A total of 335 adult patients with glioma were included. The multivariable analysis examined the association between tumor grade and POD. Then, 20 patients with left frontal lobe glioma who had presurgical structural and functional MRI data and Montreal Cognitive Assessment (MoCA) in this cohort were analyzed. We measured the gray matter volume (GMV) and functional connectivity (FC) in patients with (n = 8) and without (n = 12) POD and healthy controls (HCs, n = 29) to detect the correlation between the structural and functional alteration and POD. Results The incidence of POD was 37.3%. Multivariable regression revealed that high-grade glioma had approximately six times the odds of POD. Neuroimaging data showed that compared with HC, the patients with left frontal lobe glioma showed significantly increased GMV of the right dorsal lateral prefrontal cortex (DLPFC) in the non-POD group and decreased GMV of right DLPFC in the POD group, and the POD group exhibited significantly decreased FC of right DLPFC, and the non-POD group showed the increasing tendency. Partial correlation analysis showed that GMV in contralesional DLPFC were positively correlated with preoperative neurocognition, and the GMV and FC in contralesional DLPFC were negatively correlated with POD. Conclusions Our findings suggested that insufficient compensation for injured brain regions involving cognition might be more vulnerable to suffering from POD.
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Affiliation(s)
- Hua-Wei Huang
- Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Xiao-Kang Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Brain Tumor, Center of Brain Tumor, China National Clinical Research Center for Neurological Diseases (NCRC-ND), Beijing, China
| | - Hao-Yi Li
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Brain Tumor, Center of Brain Tumor, China National Clinical Research Center for Neurological Diseases (NCRC-ND), Beijing, China
| | - Yong-Gang Wang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Brain Tumor, Center of Brain Tumor, China National Clinical Research Center for Neurological Diseases (NCRC-ND), Beijing, China
| | - Bin Jing
- School of Biomedical Engineering, Capital Medical University, Beijing, China
| | - You Chen
- Department of Biomedical Informatics, Vanderbilt University, Nashville, TN, United States
- Department of Electrical Engineering & Computer Science, Vanderbilt University, Nashville, TN, United States
| | - Mayur B. Patel
- Section of Surgical Sciences, Department of Surgery and Neurosurgery, Division of Trauma, Surgical Critical Care, and Emergency General Surgery, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Hearing & Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, United States
- Geriatric Research, Education, and Clinical Center Service, Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, United States
| | - E. Wesley Ely
- Critical Illness, Brain Dysfunction, and Survivorship Center, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Ya-Ou Liu
- Department of Radiology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jian-Xin Zhou
- Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- *Correspondence: Jian-Xin Zhou,
| | - Song Lin
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Brain Tumor, Center of Brain Tumor, China National Clinical Research Center for Neurological Diseases (NCRC-ND), Beijing, China
- *Correspondence: Jian-Xin Zhou,
| | - Guo-Bin Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Brain Tumor, Center of Brain Tumor, China National Clinical Research Center for Neurological Diseases (NCRC-ND), Beijing, China
- *Correspondence: Jian-Xin Zhou,
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Robinson SA, Hill-Smith TE, Lucki I. Buprenorphine prevents stress-induced blunting of nucleus accumbens dopamine response and approach behavior to food reward in mice. Neurobiol Stress 2019; 11:100182. [PMID: 31304200 PMCID: PMC6599912 DOI: 10.1016/j.ynstr.2019.100182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/26/2019] [Accepted: 06/04/2019] [Indexed: 11/26/2022] Open
Abstract
Alterations to the mesolimbic dopamine (DA) system are thought to underlie dysfunctional reward processing in stress-related psychiatric disorders. Using in vivio microdialysis in awake freely moving mice, we assessed the effects of stress on the motivational and neurochemical correlates underlying conditioned approach behavior for palatable food in the non-deprived mouse. Mice trained to approach and consume food in a familiar environment exhibited a 30% increase in nucleus accumbens shell (AcbSh) extracellular dopamine levels coincident with approach towards and consumption of the food reward. This effect was not observed in mice that were presented with the food in an unfamiliar environment or were exposed for the first time and were region specific. The addition of an acute environmental stressor (bright light and novel scent) during food exposure decreased DA release and delayed approach to the food. The disruptive impact of acute novelty stress on DA levels and approach behavior was reversed in animals pretreated with buprenorphine, an opioid drug with antidepressant-like and anxiolytic effects. Together, these data indicate that exposure to mild stress reduces incentive drive to approach palatable food via alterations in AcbSh dopamine responsiveness to food reward. Moreover, they implicate the brain opioid system as a potential pharmacological target for counteracting behavioral and neurochemical elements associated with stress.
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Affiliation(s)
- Shivon A. Robinson
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | | | - Irwin Lucki
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA, 19104, USA
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4
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Exploring the involvement of Tac2 in the mouse hippocampal stress response through gene networking. Gene 2019; 696:176-185. [PMID: 30769143 DOI: 10.1016/j.gene.2019.02.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/05/2019] [Accepted: 02/01/2019] [Indexed: 01/15/2023]
Abstract
Tachykinin 2 (Tac2) is expressed in a number of areas throughout the brain, including the hippocampus. However, knowledge about its function has been only well explored in the hypothalamus in the context of reproductive health. In this study, we identified and validated increased hippocampal Tac2 mRNA expression in response to chronic mild stress in mice. Expression quantitative trait locus (eQTL) analysis showed Tac2 is cis-regulated in the hippocampus. Using a systems genetics approach, we constructed a Tac2 co-expression network to better understand the relationship between Tac2 and the hippocampal stress response. Our network identified 69 total genes associated with Tac2, several of which encode major neuropeptides involved in hippocampal stress signaling as well as critical genes for producing neural plasticity, indicating that Tac2 is involved in these processes. Pathway analysis for the member of Tac2 gene network revealed a strong connection between Tac2 and neuroactive ligand-receptor interaction, calcium signaling pathway, as well as cardiac muscle contraction. In addition, we also identified 46 stress-related phenotypes, specifically fear conditioning response, that were significantly correlated with Tac2 expression. Our results provide evidence for Tac2 as a strong candidate gene who likely plays a role in hippocampal stress processing and neural plasticity.
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Bhardwaj SK, Dodat F, Lévesque D, Srivastava LK. Altered regulation of Nur77 nuclear receptor gene expression in the mesocorticolimbic regions of rat brain by amphetamine sensitization. Brain Res 2018; 1694:46-54. [PMID: 29750935 DOI: 10.1016/j.brainres.2018.05.007] [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: 02/06/2018] [Revised: 04/17/2018] [Accepted: 05/07/2018] [Indexed: 11/19/2022]
Abstract
The mechanisms underlying psychostimulant drug-induced sensitization include long-term cellular and molecular adaptations in dopaminergic circuits. Nur77, a member of the Nur family of transcription factors, is expressed in brain regions receiving dopamine inputs and plays a role in activity-induced synaptic modification. Here we evaluated changes in Nur77 mRNA levels in the medial prefrontal cortex (mPFC), dorsal striatum (Str) and nucleus accumbens (NAc) of rats receiving a repeated, sensitizing regimen of amphetamine (AMPH). Results were compared to two groups of controls - animals receiving repeated injections of saline (Rp-SAL) or with no treatment (CON). Two weeks after the last injection, the effect of an acute challenge dose of AMPH on Nur77 expression was evaluated using in-situ hybridization. Repeated AMPH treatment (Rp-AMPH) increased the levels of Nur77 mRNA in the mPFC, NAc core and shell regions. However, the effects of an acute injection of AMPH in each of the three groups of animals was distinct. Whereas an acute AMPH led to a significant increase of Nur77 in all brain regions of the CON animals, it had no significant effect in Rp-SAL animals. Interestingly, in acute AMPH-injected Rp-AMPH animals, Nur77 mRNA levels in the mPFC, Str and NAc regions were significantly lower compared to CON and Rp-SAL animals treated with acute AMPH. There was a positive correlation between AMPH -induced locomotor activity and Nur77 mRNA expression in CON animals; however, this relationship was absent in Rp-SAL and Rp-AMPH animals. The data suggest that Nur77 is a part of neuroadaptive changes caused by either mild stress of repeated injections as well as AMPH-sensitization and may play a role in abnormal behaviors induced by the drug.
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Affiliation(s)
- Sanjeev K Bhardwaj
- Douglas Mental Health Research Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Fatéma Dodat
- Faculty of Pharmacy, Université de Montréal, Montreal, Quebec, Canada
| | - Daniel Lévesque
- Faculty of Pharmacy, Université de Montréal, Montreal, Quebec, Canada
| | - Lalit K Srivastava
- Douglas Mental Health Research Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada.
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Ambrée O, Klassen I, Förster I, Arolt V, Scheu S, Alferink J. Reduced locomotor activity and exploratory behavior in CC chemokine receptor 4 deficient mice. Behav Brain Res 2016; 314:87-95. [PMID: 27469058 DOI: 10.1016/j.bbr.2016.07.041] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 07/20/2016] [Accepted: 07/22/2016] [Indexed: 10/21/2022]
Abstract
Chemokines and their receptors are key regulators of immune cell trafficking and activation. Recent findings suggest that they may also play pathophysiological roles in psychiatric diseases like depression and anxiety disorders. The CC chemokine receptor 4 (CCR4) and its two ligands, CCL17 and CCL22, are functionally involved in neuroinflammation as well as anti-infectious and autoimmune responses. However, their influence on behavior remains unknown. Here we characterized the functional role of the CCR4-CCL17 chemokine-receptor axis in the modulation of anxiety-related behavior, locomotor activity, and object exploration and recognition. Additionally, we investigated social exploration of CCR4 and CCL17 knockout mice and wild type (WT) controls. CCR4 knockout (CCR4(-/-)) mice exhibited fewer anxiety-related behaviors in the elevated plus-maze, diminished locomotor activity, exploratory behavior, and social exploration, while their recognition memory was not affected. In contrast, CCL17 deficient mice did not show an altered behavior compared to WT mice regarding locomotor activity, anxiety-related behavior, social exploration, and object recognition memory. In the dark-light and object recognition tests, CCL17(-/-) mice even covered longer distances than WT mice. These data demonstrate a mechanistic or developmental role of CCR4 in the regulation of locomotor and exploratory behaviors, whereas the ligand CCL17 appears not to be involved in the behaviors measured here. Thus, either CCL17 and the alternative ligand CCL22 may be redundant, or CCL22 is the main activator of CCR4 in these processes. Taken together, these findings contribute to the growing evidence regarding the involvement of chemokines and their receptors in the regulation of behavior.
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Affiliation(s)
- Oliver Ambrée
- Department of Psychiatry, University of MÃŒnster, MÃŒnster, Germany; Department of Behavioural Biology, University of OsnabrÃŒck, OsnabrÃŒck, Germany.
| | - Irene Klassen
- Department of Psychiatry, University of MÃŒnster, MÃŒnster, Germany
| | - Irmgard Förster
- Immunology and Environment, Life & Medical Sciences Institute (LIMES), University of Bonn, Germany
| | - Volker Arolt
- Department of Psychiatry, University of MÃŒnster, MÃŒnster, Germany
| | - Stefanie Scheu
- Institute of Medical Microbiology and Hospital Hygiene, University of DÃŒsseldorf, DÃŒsseldorf, Germany
| | - Judith Alferink
- Department of Psychiatry, University of MÃŒnster, MÃŒnster, Germany; Cluster of Excellence EXC 1003, Cells in Motion, University of MÃŒnster, MÃŒnster, Germany
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Shioiri A, Kurumaji A, Takeuchi T, Nemoto K, Arai H, Nishikawa T. A Decrease in the Volume of Gray Matter as a Risk Factor for Postoperative Delirium Revealed by an Atlas-based Method. Am J Geriatr Psychiatry 2016; 24:528-36. [PMID: 26654288 DOI: 10.1016/j.jagp.2015.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 08/25/2015] [Accepted: 09/09/2015] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Delirium is a common syndrome in older patients after surgery. Although an atrophic change in the whole brain may be a potential risk factor for postoperative delirium, the anatomically specific change related to the vulnerability still remains a significant issue. DESIGN Prospective study. SETTING University hospital. PARTICIPANTS 116 consecutive patients who underwent elective cardiac operations. MEASUREMENTS Before the surgery, magnetic resonance imaging (MRI) was evaluated. The MRI data were processed to calculate the absolute volumes of the predefined region of interest using Statistical Parametrical Mapping 8 with an atlas-based method. The evaluated volume was expressed as the fraction (%) of the total intracranial volume. Postoperative delirium was diagnosed according to the DSM-IV criteria for delirium. RESULTS Delirium developed in 19 of 116 patients (16.4%) with an age range from 58 to 84 years. Based on a comparison with the age-controlled non-delirium patients (over 57 years; nâ=â65), a statistically significant reduction in the gray matter volume of the delirium patients was observed in the defined gyri of the temporal and limbic lobes. Moreover, a moderate value (>0.8) of area under the curve to predict postoperative delirium was revealed by receiver operating characteristic curve analysis of the gyri of temporal lobe. CONCLUSIONS The decreased volume of gray matter could be associated with the vulnerability to delirium after surgery. The atlas-based method would be a potential tool to pre-screen the brain structure of individual patients for the prediction of postoperative delirium.
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Affiliation(s)
- Akiko Shioiri
- Section of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
| | - Akeo Kurumaji
- Section of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
| | - Takashi Takeuchi
- Section of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
| | - Kiyotaka Nemoto
- Department of NeuropsychiatryInstitute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan
| | - Hirokuni Arai
- Department of Cardiovascular Surgery, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
| | - Toru Nishikawa
- Section of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University Graduate School, Tokyo, Japan
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Ikeno T, Deats SP, Soler J, Lonstein JS, Yan L. Decreased daytime illumination leads to anxiety-like behaviors and HPA axis dysregulation in the diurnal grass rat (Arvicanthis niloticus). Behav Brain Res 2015; 300:77-84. [PMID: 26684510 DOI: 10.1016/j.bbr.2015.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/18/2015] [Accepted: 12/07/2015] [Indexed: 12/16/2022]
Abstract
The impact of ambient light on mood and anxiety is best exemplified in seasonal affective disorder, in which patients experience depression and anxiety in winter when there is less light in the environment. However, the brain mechanisms underlying light-dependent changes in affective state remain unclear. Our previous work revealed increased depression-like behaviors in the diurnal Nile grass rat (Arvicanthis niloticus) housed in a dim light-dark (dim-LD) cycle as compared to the controls housed in a bright light-dark (bright-LD) condition. As depression is often comorbid with anxiety and is associated with dysregulation of the body's stress response system, the present study examined the anxiety-like behaviors as well as indicators of the hypothalamic-pituitary-adrenal (HPA) axis functioning in the grass rats. Animals housed in dim-LD showed increased anxiety-like behaviors compared to bright-LD controls, as revealed by fewer entries and less time spent at the center in the open field test and more marbles buried during the marble-burying test. Following the marble-burying test, dim-LD animals showed higher plasma corticosterone (CORT) levels and hippocampal Fos expression. Although the daily CORT rhythm was comparable between bright-LD and dim-LD groups, the day/night variation of corticotropin-releasing hormone mRNA expression in the paraventricular nucleus was diminished in dim-LD animals. In addition, glucocorticoid receptor and mineralocorticoid receptor mRNA expression were higher in the hippocampus of dim-LD animals. The results suggest that in diurnal species, reduced daytime illumination can lead to increased anxiety-like behaviors and altered HPA axis functioning, providing insights into the link between decreased environmental illumination and negative emotion.
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Affiliation(s)
- Tomoko Ikeno
- Department of Psychology, Michigan State University, East Lansing, MI 48824, USA.
| | - Sean P Deats
- Department of Psychology, Michigan State University, East Lansing, MI 48824, USA.
| | - Joel Soler
- Department of Psychology, Michigan State University, East Lansing, MI 48824, USA.
| | - Joseph S Lonstein
- Department of Psychology, Michigan State University, East Lansing, MI 48824, USA; Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA.
| | - Lily Yan
- Department of Psychology, Michigan State University, East Lansing, MI 48824, USA; Neuroscience Program, Michigan State University, East Lansing, MI 48824, USA.
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Role of hippocampal β-adrenergic and glucocorticoid receptors in the novelty-induced enhancement of fear extinction. J Neurosci 2015; 35:8308-21. [PMID: 26019344 DOI: 10.1523/jneurosci.0005-15.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Fear extinction forms a new memory but does not erase the original fear memory. Exposure to novelty facilitates transfer of short-term extinction memory to long-lasting memory. However, the underlying cellular and molecular mechanisms are still unclear. Using a classical contextual fear-conditioning model, we investigated the effect of novelty on long-lasting extinction memory in rats. We found that exposure to a novel environment but not familiar environment 1 h before or after extinction enhanced extinction long-term memory (LTM) and reduced fear reinstatement. However, exploring novelty 6 h before or after extinction had no such effect. Infusion of the β-adrenergic receptor (βAR) inhibitor propranolol and glucocorticoid receptor (GR) inhibitor RU486 into the CA1 area of the dorsal hippocampus before novelty exposure blocked the effect of novelty on extinction memory. Propranolol prevented activation of the hippocampal PKA-CREB pathway, and RU486 prevented activation of the hippocampal extracellular signal-regulated kinase 1/2 (Erk1/2)-CREB pathway induced by novelty exposure. These results indicate that the hippocampal βAR-PKA-CREB and GR-Erk1/2-CREB pathways mediate the extinction-enhancing effect of novelty exposure. Infusion of RU486 or the Erk1/2 inhibitor U0126, but not propranolol or the PKA inhibitor Rp-cAMPS, into the CA1 before extinction disrupted the formation of extinction LTM, suggesting that hippocampal GR and Erk1/2 but not βAR or PKA play critical roles in this process. These results indicate that novelty promotes extinction memory via hippocampal βAR- and GR-dependent pathways, and Erk1/2 may serve as a behavioral tag of extinction.
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11
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Dorsal and ventral hippocampus modulate autonomic responses but not behavioral consequences associated to acute restraint stress in rats. PLoS One 2013; 8:e77750. [PMID: 24147071 PMCID: PMC3798415 DOI: 10.1371/journal.pone.0077750] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 09/06/2013] [Indexed: 11/19/2022] Open
Abstract
Recent evidence has suggested that the dorsal (DH) and the ventral (VH) poles of the hippocampus are structurally, molecularly and functionally different regions. While the DH is preferentially involved in the modulation of spatial learning and memory, the VH modulates defensive behaviors related to anxiety. Acute restraint is an unavoidable stress situation that evokes marked and sustained autonomic changes, which are characterized by elevated blood pressure (BP), intense heart rate (HR) increases, skeletal muscle vasodilatation and cutaneous vasoconstriction, which are accompanied by a rapid skin temperature drop followed by body temperature increases. In addition to those autonomic responses, animals submitted to restraint also present behavioral changes, such as reduced exploration of the open arms of an elevated plus-maze (EPM), an anxiogenic-like effect. In the present work, we report a comparison between the effects of pharmacological inhibition of DH and VH neurotransmission on autonomic and behavioral responses evoked by acute restraint stress in rats. Bilateral microinjection of the unspeciï¬c synaptic blocker cobalt chloride (CoCl2, 1mM) into the DH or VH attenuated BP and HR responses, as well as the decrease in the skin temperature, elicited by restraint stress exposure. Moreover, DH or VH inhibition before restraint did not change the delayed increased anxiety behavior observed 24 h later in the EPM. The present results demonstrate for the ï¬rst time that both DH and VH mediate stress-induced autonomic responses to restraint but they are not involved in the modulation of the delayed emotional consequences elicited by such stress.
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Kurumaji A, Nishikawa T. An anxiogenic drug, FG 7142, induced an increase in mRNA of Btg2 and Adamts1 in the hippocampus of adult mice. Behav Brain Funct 2012; 8:43. [PMID: 22913326 PMCID: PMC3541064 DOI: 10.1186/1744-9081-8-43] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 08/09/2012] [Indexed: 01/03/2023] Open
Abstract
Background Anxiety and stress-related disorders are among the most common psychiatric disorders. The hippocampus is a crucial brain area involved in the neural circuits of the pathophysiology of anxiety and stress-related disorders, and GABA is one of most important neurotransmitters related to these disorders. An anxiogenic drug and a pharmacological stressor, FG7142 (N-methyl-Ã-carboline-3-carboxamide), produces anxiety in humans and experimental animals, acting at the benzodiazepine sites of the GABAA receptors as a partial inverse agonist. This drug as well as immobilization stress produced an increased mRNA in a number of genes, e.g., Btg2 and Adamsts1, in the cortex of rodents. The present study was carried out to clarify the effect of the anxiogenic drug on the gene expressions in the hippocampus and to obtain a new insight into the GABAergic system involved in the pathophysiology of the disorders. Method We examined the effects of FG7142 on the gene expression of Btg2 and Adamts1 in the hippocampus of mice using a quantitative RT-PCR method as well as an in situ hybridization method. Results The intraperitoneal administration of FG7142 at a dose of 20âmg/kg, but not 10âmg/kg, induced a statistically significant increase in the hippocampal mRNA of both genes in adult mice (postnatal days 56), being blocked by co-administrations of flumazenil (twice of 10âmg/kg, i.p.), an antagonist at the benzodiazepine binding site, while FG7142 failed to produce any change in the gene expressions in infant mice (postnatal days 8). In addition, the in situ hybridization experiment demonstrated an upregulation of the gene expressions restricted to the dentate gyrus of the hippocampus in adult mice. Conclusions The present study suggests a functional coupling between the GABAergic system and the transcriptional regulation of the two genes (Btg2 and Adamsts1) in the hippocampus of adult mice, which may play a role in the brain function related to anxiety and stress such as memory of fear.
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Affiliation(s)
- Akeo Kurumaji
- Section of Psychiatry and Behavioral Sciences, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
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