1
|
Kantor S, Lanigan M, Giggins L, Lione L, Magomedova L, de Lannoy I, Upton N, Duxon M. Ketamine supresses REM sleep and markedly increases EEG gamma oscillations in the Wistar Kyoto rat model of treatment-resistant depression. Behav Brain Res 2023; 449:114473. [PMID: 37146722 DOI: 10.1016/j.bbr.2023.114473] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/10/2023] [Accepted: 03/20/2023] [Indexed: 05/07/2023]
Abstract
Wistar-Kyoto (WKY) rats exhibit depression-like characteristics and decreased sensitivity to monoamine-based antidepressants, making them a suitable model of treatment-resistant depression (TRD). Ketamine has emerged recently as a rapidly acting antidepressant with high efficacy in TRD. Our aim was to determine whether subanaesthetic doses of ketamine can correct sleep and electroencephalogram (EEG) alterations in WKY rats and whether any ketamine-induced changes differentially affect WKY rats compared to Sprague-Dawley (SD) rats. Thus, we surgically implanted 8SD and 8 WKY adult male rats with telemetry transmitters and recorded their EEG, electromyogram, and locomotor activity after vehicle or ketamine (3, 5 or 10mg/kg, s.c.) treatment. We also monitored the plasma concentration of ketamine and its metabolites, norketamine and hydroxynorketamine in satellite animals. We found that WKY rats, have an increased amount of rapid eye movement (REM) sleep, fragmented sleep-wake pattern, and increased EEG delta power during non-REM sleep compared to SD rats. Ketamine suppressed REM sleep and increased EEG gamma power during wakefulness in both strains, but the gamma increase was almost twice as large in WKY rats than in SD rats. Ketamine also increased beta oscillations, but only in WKY rats. These differences in sleep and EEG are unlikely to be caused by dissimilarities in ketamine metabolism as the plasma concentrations of ketamine and its metabolites were similar in both strains. Our data suggest an enhanced antidepressant-like response to ketamine in WKY rats, and further support the predictive validity of acute REM sleep suppression as a measure of antidepressant responsiveness.
Collapse
Affiliation(s)
- Sandor Kantor
- Transpharmation Ltd, 2 Royal College Street, London, NW1 0NH, United Kingdom; Transpharmation Canada, Fergus, ON, N1M 2W8, Canada.
| | - Michael Lanigan
- Transpharmation Ltd, 2 Royal College Street, London, NW1 0NH, United Kingdom; University of Hertfordshire, College Lane, Hatfield, Herts, AL10 9AD, United Kingdom
| | - Lauren Giggins
- Transpharmation Ltd, 2 Royal College Street, London, NW1 0NH, United Kingdom
| | - Lisa Lione
- University of Hertfordshire, College Lane, Hatfield, Herts, AL10 9AD, United Kingdom
| | | | | | - Neil Upton
- Transpharmation Ltd, 2 Royal College Street, London, NW1 0NH, United Kingdom
| | - Mark Duxon
- Transpharmation Ltd, 2 Royal College Street, London, NW1 0NH, United Kingdom; Transpharmation Canada, Fergus, ON, N1M 2W8, Canada
| |
Collapse
|
2
|
DaSilva JK, Lei Y, Morrison AR, Tejani-Butt S. Social environment during fear extinction alters the binding of [3H] MK-801 to N-methyl-D-aspartic acid receptors in Wistar-Kyoto and Wistar rats. Med Chem Res 2022. [DOI: 10.1007/s00044-022-02865-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
3
|
Lack of Glutamate Receptor Subunit Expression Changes in Hippocampal Dentate Gyrus after Experimental Traumatic Brain Injury in a Rodent Model of Depression. Int J Mol Sci 2021; 22:ijms22158086. [PMID: 34360865 PMCID: PMC8347641 DOI: 10.3390/ijms22158086] [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: 06/21/2021] [Revised: 07/23/2021] [Accepted: 07/24/2021] [Indexed: 11/16/2022] Open
Abstract
Traumatic brain injury (TBI) affects over 69 million people annually worldwide, and those with pre-existing depression have worse recovery. The molecular mechanisms that may contribute to poor recovery after TBI with co-morbid depression have not been established. TBI and depression have many commonalities including volume changes, myelin disruption, changes in proliferation, and changes in glutamatergic signaling. We used a well-established animal model of depression, the Wistar Kyoto (WKY) rat, to elucidate changes after TBI that may influence the recovery trajectory. We compared the histological and molecular outcomes in the hippocampal dentate gyrus after experimental TBI using the lateral fluid percussion injury (LFPI) in the WKY and the parent Wistar (WIS) strain. We showed that WKY had exaggerated myelin loss after LFPI and baseline deficits in proliferation. In addition, we showed that while after LFPI WIS rats exhibited glutamate receptor subunit changes, namely increased GluN2B, the WKY rats failed to show such injury-related changes. These differential responses to LFPI helped to elucidate the molecular characteristics that influence poor recovery after TBI in those with pre-existing depression and may lead to targets for future therapeutic interventions.
Collapse
|
4
|
Munshi S, Rosenkranz JA, Caccamise A, Wolf ME, Corbett CM, Loweth JA. Cocaine and chronic stress exposure produce an additive increase in neuronal activity in the basolateral amygdala. Addict Biol 2021; 26:e12848. [PMID: 31750602 DOI: 10.1111/adb.12848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/30/2019] [Accepted: 10/04/2019] [Indexed: 12/21/2022]
Abstract
Cocaine addiction is a chronic, relapsing disorder. Stress and cues related to cocaine are two common relapse triggers. We have recently shown that exposure to repeated restraint stress during early withdrawal accelerates the time-dependent intensification or "incubation" of cue-induced cocaine craving that occurs during the first month of withdrawal, although craving ultimately plateaus at the same level observed in controls. These data indicate that chronic stress exposure during early withdrawal may result in increased vulnerability to cue-induced relapse during this period. Previous studies have shown that chronic stress exposure in drug-naïve rats increases neuronal activity in the basolateral amygdala (BLA), a region critical for behavioral responses to stress. Given that glutamatergic projections from the BLA to the nucleus accumbens are critical for the incubation of cue-induced cocaine craving, we hypothesized that cocaine withdrawal and chronic stress exposure produce separate increases that additively increase BLA neuronal activity. To assess this, we conducted in vivo extracellular single-unit recordings from the BLA of anesthetized adult male rats following cocaine or saline self-administration (6 h/day for 10 days) and repeated restraint stress or control conditions on withdrawal days (WD) 6-14. Recordings were conducted from WD15 to WD20. Interestingly, cocaine exposure alone increased the spontaneous firing rate in the BLA to levels observed following chronic stress exposure in drug-naïve rats. Chronic stress exposure during cocaine withdrawal further increased firing rate. These studies may identify a potential mechanism by which both cocaine and chronic stress exposure drive cue-induced relapse vulnerability during abstinence.
Collapse
Affiliation(s)
- Soumyabrata Munshi
- Department of Neuroscience Rosalind Franklin University of Medicine and Science North Chicago IL USA
- Department of Cellular and Molecular Pharmacology Rosalind Franklin University of Medicine and Science North Chicago IL USA
| | - J. Amiel Rosenkranz
- Department of Cellular and Molecular Pharmacology Rosalind Franklin University of Medicine and Science North Chicago IL USA
- Center for the Neurobiology of Stress Resilience and Psychiatric Disorders Rosalind Franklin University of Medicine and Science North Chicago IL USA
| | - Aaron Caccamise
- Department of Neuroscience Rosalind Franklin University of Medicine and Science North Chicago IL USA
- Department of Biomedical Sciences Marquette University Milwaukee WI USA
| | - Marina E. Wolf
- Department of Neuroscience Rosalind Franklin University of Medicine and Science North Chicago IL USA
- Department of Behavioral Neuroscience Oregon Health & Science University Portland OR USA
| | - Claire M. Corbett
- Graduate School of Biomedical Sciences, Department of Cell Biology and Neuroscience Rowan University School of Osteopathic Medicine Stratford NJ USA
| | - Jessica A. Loweth
- Department of Neuroscience Rosalind Franklin University of Medicine and Science North Chicago IL USA
- Graduate School of Biomedical Sciences, Department of Cell Biology and Neuroscience Rowan University School of Osteopathic Medicine Stratford NJ USA
| |
Collapse
|
5
|
Thangaleela S, Ragu Varman D, Sivasangari K, Rajan KE. Inhibition of monoamine oxidase attenuates social defeat-induced memory impairment in goldfish, (Carassius auratus): A possible involvement of synaptic proteins and BDNF. Comp Biochem Physiol C Toxicol Pharmacol 2021; 239:108873. [PMID: 32805442 DOI: 10.1016/j.cbpc.2020.108873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 01/12/2023]
Abstract
Social defeat (SD) has been implicated in different modulatory effects of physiology and behaviour including learning and memory. We designed an experiment to test the functional role of monoamine oxidase (MAO) in regulation of synaptic transmission, synaptic plasticity and memory in goldfish Carassius auratus. To test this, individuals were divided into three groups: (i) control; (ii) social defeat (SD) group (individuals were subjected to social defeat for 10 min by Pseudotropheus demasoni) and (iii) SD + MAO inhibitor pre-treated group. All experimental groups were subjected to spatial learning and then memory. Our results suggest that SD affects a spatial learning and memory, whereas SD exerts no influence on MAOI pre-treated group. In addition, we noted that the expression of monoamine oxidase-A (MAO-A) was up-regulated and level of serotonin (5-hydroxytryptamine; 5-HT), expression of serotonin transporter (SERT), synaptophysin (SYP), synaptotagmin -1 (SYT-1), N-methyl-D-asparate (NMDA) receptors subunits (NR2A and NR2B), postsynaptic density-95 (PSD-95) and brain-derived neurotrophic factor (BDNF) were reduced by SD, while MAOIs pretreatment protects the effect of SD. Taken together, our results suggest that MAO is an essential component in the serotonergic system that finely tunes the level of 5-HT, which further regulates the molecules involving in synaptic transmission, synaptic plasticity and memory.
Collapse
Affiliation(s)
- Subramanian Thangaleela
- Behavioural Neuroscience Laboratory, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India
| | - Durairaj Ragu Varman
- Behavioural Neuroscience Laboratory, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India; Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, United States
| | - Karunanithi Sivasangari
- Behavioural Neuroscience Laboratory, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India
| | - Koilmani Emmanuvel Rajan
- Behavioural Neuroscience Laboratory, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli 620 024, India.
| |
Collapse
|
6
|
Jeyaraj SE, Sivasangari K, García-Colunga J, Rajan KE. Environmental enrichment enhances sociability by regulating glutamate signaling pathway through GR by epigenetic mechanisms in amygdala of Indian field mice Mus booduga. Gen Comp Endocrinol 2021; 300:113641. [PMID: 33017584 DOI: 10.1016/j.ygcen.2020.113641] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 02/07/2023]
Abstract
Environmental enrichment (EE) dynamically regulates gene expression and synaptic plasticity with positive consequences on behavior. The present study was performed on field-mice to explore the effects of EE on both captive-condition inducing social stress and epigenetic changes of molecules resilience stress. For this purpose, field-mice were caught and allowed to habituate in standard laboratory conditions for 7 days. The next day animals were randomly assigned to three groups: i) mice at short-term standard condition (STSC); which were subjected to social interaction test (SIT) on day 9, ii) mice continuously maintainedfor additional 30 days, with these long-term standard conditions (LTSC), and iii) mice maintained in an EE cage for additional 30 days. After achieving SIT, we examined epigenetic changes of a repertory of molecules associated with resilience stress, by determining their levels by Western blot. Thus, the main findings were that during SIT, EE exerted more social interaction of field-mice with the strangers compared with STSC and LTSC mice. Related with social behavior results, we found that in mice subjected to EE the levels of histone 3 lysine 9 di-methylation (H3K9me2), glucocorticoid receptor (GR), N-methyl-D asparate (NMDA) receptor subunits NR2A and NR2B, postsynaptic density protein-95 (PSD-95), and mature brain-derived neurotrophic factor (mBDNF) were significantly elevated; whereas the levels of DNA methyltransferase-3A (DNMT3A), methyl-CpG-binding protein-2 (MeCP2), repressor element-1 silencing transcription factor (REST), H3K4me2 and lysine demethylase-1A (KDM1A) decreased. These results suggest that enhanced sociability of EE mice could be mediated, in part, by altered expression of molecules regulating glutamate signaling pathway through GR by epigenetic mechanisms.
Collapse
Affiliation(s)
- Soundarrajan Edwin Jeyaraj
- Behavioural Neuroscience Laboratory, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, India
| | - Karunanithi Sivasangari
- Behavioural Neuroscience Laboratory, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, India
| | - Jesús García-Colunga
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Juriquilla, Querétaro 76230, Mexico
| | - Koilmani Emmanuvel Rajan
- Behavioural Neuroscience Laboratory, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, India.
| |
Collapse
|
7
|
Millard SJ, Weston-Green K, Newell KA. The Wistar-Kyoto rat model of endogenous depression: A tool for exploring treatment resistance with an urgent need to focus on sex differences. Prog Neuropsychopharmacol Biol Psychiatry 2020; 101:109908. [PMID: 32145362 DOI: 10.1016/j.pnpbp.2020.109908] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 01/31/2020] [Accepted: 03/03/2020] [Indexed: 02/07/2023]
Abstract
Major depressive disorder (MDD) is one of the leading causes of years lived with disability and contributor to the burden of disease worldwide. The incidence of MDD has increased by ~20% in the last decade. Currently antidepressant drugs such as the popular selective serotonin reuptake inhibitors (SSRIs) are the leading form of pharmaceutical intervention for the treatment of MDD. SSRIs however, are inefficient in ameliorating depressive symptoms in ~50% of patients and exhibit a prolonged latency of efficacy. Due to the burden of disease, there is an increasing need to understand the neurobiology underpinning MDD and to discover effective treatment strategies. Endogenous models of MDD, such as the Wistar-Kyoto (WKY) rat provide a valuable tool for investigating the pathophysiology of MDD. The WKY rat displays behavioural and neurobiological phenotypes similar to that observed in clinical cases of MDD, as well as resistance to common antidepressants. Specifically, the WKY strain exhibits increased anxiety- and depressive-like behaviours, as well as alterations in Hypothalamic Pituitary Adrenal (HPA) axis, serotonergic, dopaminergic and neurotrophic systems with emerging studies suggesting an involvement of neuroinflammation. More recent investigations have shown evidence for reduced cortical and hippocampal volumes and altered glutamatergic signalling in the WKY strain. Given the growing interest in therapeutics targeting the glutamatergic system, the WKY strain presents itself as a potentially useful tool for screening novel antidepressant drugs and their efficacy against treatment resistant depression. However, despite the sexual dimorphism present in the pathophysiology and aetiology of MDD, sex differences in the WKY model are rarely investigated, with most studies focusing on males. Accordingly, this review highlights what is known regarding sex differences and where further research is needed. Whilst acknowledging that investigation into a range of depression models is required to fully elucidate the underlying mechanisms of MDD, here we review the WKY strain, and its relevance to the clinic.
Collapse
Affiliation(s)
- Samuel J Millard
- School of Medicine and Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia.
| | - Katrina Weston-Green
- School of Medicine and Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia.
| | - Kelly A Newell
- School of Medicine and Molecular Horizons, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, New South Wales 2522, Australia; Illawarra Health and Medical Research Institute, Wollongong, New South Wales 2522, Australia.
| |
Collapse
|
8
|
Aleksandrova LR, Wang YT, Phillips AG. Evaluation of the Wistar-Kyoto rat model of depression and the role of synaptic plasticity in depression and antidepressant response. Neurosci Biobehav Rev 2019; 105:1-23. [DOI: 10.1016/j.neubiorev.2019.07.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/10/2019] [Accepted: 07/08/2019] [Indexed: 12/28/2022]
|
9
|
Aten S, Page CE, Kalidindi A, Wheaton K, Niraula A, Godbout JP, Hoyt KR, Obrietan K. miR-132/212 is induced by stress and its dysregulation triggers anxiety-related behavior. Neuropharmacology 2019; 144:256-270. [PMID: 30342060 PMCID: PMC6823933 DOI: 10.1016/j.neuropharm.2018.10.020] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/25/2018] [Accepted: 10/14/2018] [Indexed: 02/08/2023]
Abstract
miR-132 and miR-212 are structurally-related microRNAs that are expressed from the same non-coding transcript. Accumulating evidence has shown that the dysregulation of these microRNAs contributes to aberrant neuronal plasticity and gene expression in the mammalian brain. Consistent with this, altered expression of miR-132 is associated with a number of affect-related psychiatric disorders. Here, we tested the functional contribution of the miR-132/212 locus to the development of stress-related and anxiety-like behaviors. Initially, we tested whether expression from the miR-132/212 locus is altered by stress-inducing paradigms. Using a 5-h acute-stress model, we show that both miR-132 and miR-212 are increased more than two-fold in the WT murine hippocampus and amygdala, whereas after a 15 day chronic-stress paradigm, expression of both miR-132 and miR-212 are upregulated more than two-fold within the amygdala but not in the hippocampus. Next, we used a tetracycline-inducible miR-132 overexpression mouse model and a miR-132/212 conditional knockout (cKO) mouse model to examine whether dysregulation of miR-132/212 expression alters basal anxiety-like behaviors. Interestingly, in both the miR-132 overexpression and cKO lines, significant increases in anxiety-like behaviors were detected. Importantly, suppression of transgenic miR-132 expression (via doxycycline administration) mitigated the anxiety-related behaviors. Further, expression of Sirt1 and Pten-two miR-132 target genes that have been implicated in the regulation of anxiety-were differentially regulated in the hippocampus and amygdala of miR-132/212 conditional knockout and miR-132 transgenic mice. Collectively, these data raise the prospect that miR-132 and miR-212 may play a key role in the modulation of stress responsivity and anxiety.
Collapse
Affiliation(s)
- Sydney Aten
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Chloe E Page
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Anisha Kalidindi
- Department of Neuroscience, Ohio State University, Columbus, OH, USA
| | - Kelin Wheaton
- Division of Pharmaceutics and Pharmaceutical Chemistry, Ohio State University, Columbus, OH, USA
| | - Anzela Niraula
- Department of Neuroscience, Ohio State University, Columbus, OH, USA; Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | - Jon P Godbout
- Department of Neuroscience, Ohio State University, Columbus, OH, USA; Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA; Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, OH, USA
| | - Kari R Hoyt
- Division of Pharmaceutics and Pharmaceutical Chemistry, Ohio State University, Columbus, OH, USA
| | - Karl Obrietan
- Department of Neuroscience, Ohio State University, Columbus, OH, USA.
| |
Collapse
|
10
|
Quantitative Proteomic Analysis Reveals Synaptic Dysfunction in the Amygdala of Rats Susceptible to Chronic Mild Stress. Neuroscience 2018; 376:24-39. [DOI: 10.1016/j.neuroscience.2018.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/17/2018] [Accepted: 02/06/2018] [Indexed: 02/07/2023]
|
11
|
Effects of Repeated Stress on Age-Dependent GABAergic Regulation of the Lateral Nucleus of the Amygdala. Neuropsychopharmacology 2016; 41:2309-23. [PMID: 26924679 PMCID: PMC4946062 DOI: 10.1038/npp.2016.33] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 01/25/2016] [Accepted: 02/03/2016] [Indexed: 12/17/2022]
Abstract
The adolescent age is associated with lability of mood and emotion. The onset of depression and anxiety disorders peaks during adolescence and there are differences in symptomology during adolescence. This points to differences in the adolescent neural circuitry that underlies mood and emotion, such as the amygdala. The human adolescent amygdala is more responsive to evocative stimuli, hinting to less local inhibitory regulation of the amygdala, but this has not been explored in adolescents. The amygdala, including the lateral nucleus (LAT) of the basolateral amygdala complex, is sensitive to stress. The amygdala undergoes maturational processes during adolescence, and therefore may be more vulnerable to harmful effects of stress during this time period. However, little is known about the effects of stress on the LAT during adolescence. GABAergic inhibition is a key regulator of LAT activity. Therefore, the purpose of this study was to test whether there are differences in the local GABAergic regulation of the rat adolescent LAT, and differences in its sensitivity to repeated stress. We found that LAT projection neurons are subjected to weaker GABAergic inhibition during adolescence. Repeated stress reduced in vivo endogenous and exogenous GABAergic inhibition of LAT projection neurons in adolescent rats. Furthermore, repeated stress decreased measures of presynaptic GABA function and interneuron activity in adolescent rats. In contrast, repeated stress enhanced glutamatergic drive of LAT projection neurons in adult rats. These results demonstrate age differences in GABAergic regulation of the LAT, and age differences in the mechanism for the effects of repeated stress on LAT neuron activity. These findings provide a substrate for increased mood lability in adolescents, and provide a substrate by which adolescent repeated stress can induce distinct behavioral outcomes and psychiatric symptoms.
Collapse
|
12
|
Novick AM, Mears M, Forster GL, Lei Y, Tejani-Butt SM, Watt MJ. Adolescent social defeat alters N-methyl-D-aspartic acid receptor expression and impairs fear learning in adulthood. Behav Brain Res 2016; 304:51-9. [PMID: 26876136 PMCID: PMC4795455 DOI: 10.1016/j.bbr.2016.02.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 01/27/2016] [Accepted: 02/08/2016] [Indexed: 11/19/2022]
Abstract
Repeated social defeat of adolescent male rats results in adult mesocortical dopamine hypofunction, impaired working memory, and increased contextual anxiety-like behavior. Given the role of glutamate in dopamine regulation, cognition, and fear and anxiety, we investigated potential changes to N-methyl-D-aspartic acid (NMDA) receptors following adolescent social defeat. As both NMDA receptors and mesocortical dopamine are implicated in the expression and extinction of conditioned fear, a separate cohort of rats was challenged with a classical fear conditioning paradigm to investigate whether fear learning is altered by adolescent defeat. Quantitative autoradiography was used to measure 3H-MK-801 binding to NMDA receptors in regions of the medial prefrontal cortex, caudate putamen, nucleus accumbens, amygdala and hippocampus. Assessment of fear learning was achieved using an auditory fear conditioning paradigm, with freezing toward the auditory tone used as a measure of conditioned fear. Compared to controls, adolescent social defeat decreased adult NMDA receptor expression in the infralimbic region of the prefrontal cortex and central amygdala, while increasing expression in the CA3 region of the hippocampus. Previously defeated rats also displayed decreased conditioned freezing during the recall and first extinction periods, which may be related to the observed decreases and increases in NMDA receptors within the central amygdala and CA3, respectively. The alteration in NMDA receptors seen following adolescent social defeat suggests that dysfunction of glutamatergic systems, combined with mesocortical dopamine deficits, likely plays a role in the some of the long-term behavioral consequences of social stressors in adolescence seen in both preclinical and clinical studies.
Collapse
Affiliation(s)
- Andrew M Novick
- Center for Brain and Behavior Research, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, 414 E. Clark St., Vermillion, SD 57069, USA.
| | - Mackenzie Mears
- Center for Brain and Behavior Research, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, 414 E. Clark St., Vermillion, SD 57069, USA
| | - Gina L Forster
- Center for Brain and Behavior Research, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, 414 E. Clark St., Vermillion, SD 57069, USA
| | - Yanlin Lei
- Department of Pharmaceutical Sciences, University of the Sciences in Philadelphia, 600 S 43rd St., Philadelphia, PA 19104, USA
| | - Shanaz M Tejani-Butt
- Department of Pharmaceutical Sciences, University of the Sciences in Philadelphia, 600 S 43rd St., Philadelphia, PA 19104, USA
| | - Michael J Watt
- Center for Brain and Behavior Research, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, 414 E. Clark St., Vermillion, SD 57069, USA
| |
Collapse
|
13
|
Bahi A, Sadek B, Nurulain SM, Łażewska D, Kieć-Kononowicz K. The novel non-imidazole histamine H3 receptor antagonist DL77 reduces voluntary alcohol intake and ethanol-induced conditioned place preference in mice. Physiol Behav 2015; 151:189-97. [PMID: 26169446 DOI: 10.1016/j.physbeh.2015.07.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 06/28/2015] [Accepted: 07/08/2015] [Indexed: 12/16/2022]
Abstract
It has become clear that histamine H3 receptors (H3R) have been implicated in modulating ethanol intake and preference in laboratory animals. The novel non-imidazole H3R antagonist DL77 with excellent selectivity profile shows high in-vivo potency as well as in-vitro antagonist affinity with ED50 of 2.1 ± 0.2 mg/kg and pKi=8.08, respectively. In the present study, and applying an unlimited access two-bottle choice procedure, the anti-alcohol effects of the H3R antagonist, DL77 (0, 3, 10 and 30 mg/kg; i.p.), were investigated in adult mice. In this C57BL/6 line, effects of DL77 on voluntary alcohol intake and preference, as well as on total fluid intake were evaluated. Results have shown that DL77, dose-dependently, reduced both ethanol intake and preference. These effects were very selective as both saccharin and quinine, used to control for taste sensitivity, and intakes were not affected following DL77 pre-application. More importantly, systemic administration of DL77 (10 mg/kg) during acquisition inhibited ethanol-induced conditioned-place preference (EtOH-CPP) as measured using an unbiased protocol. The anti-alcohol activity observed for DL77 was abrogated when mice were pretreated with the selective H3R agonist R-(α)-methyl-histamine (RAMH) (10 mg/kg), or with the CNS penetrant H1R antagonist pyrilamine (PYR) (10mg/kg). These results suggest that DL77 has a predominant role in two in vivo effects of ethanol. Therefore, signaling via H3R is essential for ethanol-related consumption and conditioned reward and may represent a novel therapeutic pharmacological target to tackle ethanol abuse and alcoholism.
Collapse
Affiliation(s)
- Amine Bahi
- Department of Anatomy, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
| | - Bassem Sadek
- Department of Pharmacology & Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Syed M Nurulain
- Department of Pharmacology & Therapeutics, College of Medicine & Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Dorota Łażewska
- Jagiellonian University-Medical College, Faculty of Pharmacy, Department of Technology and Biotechnology of Drugs, Medyczna 9 St., 30-688 Kraków, Poland
| | - Katarzyna Kieć-Kononowicz
- Jagiellonian University-Medical College, Faculty of Pharmacy, Department of Technology and Biotechnology of Drugs, Medyczna 9 St., 30-688 Kraków, Poland
| |
Collapse
|
14
|
Garbusow M, Sebold M, Beck A, Heinz A. Too difficult to stop: mechanisms facilitating relapse in alcohol dependence. Neuropsychobiology 2015; 70:103-10. [PMID: 25359490 DOI: 10.1159/000362838] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 04/13/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND In alcohol and other substance dependencies, patients often suffer relapse despite better knowledge and their intention to remain abstinent. A variety of neurotransmitter systems and their respective alterations due to the chronic drug intake are involved in mechanisms that facilitate relapse. It has been postulated that these neurotransmitter systems are related to changes in motivational and learning mechanisms, and engender a shift from goal-directed to habitual behavior in dependent patients that facilitates drug-seeking behavior. METHODS We review learning mechanisms facilitating relapse, as identified and tested to date. We focus on studies examining the interaction between alcohol-related changes in monoaminergic neurotransmission and their respective effects on pavlovian and operant learning mechanisms in alcohol dependence. RESULTS Animal experiments and first human studies suggest that chronic alcohol intake impairs goal-directed behavior and facilitates habitual drug intake. Key symptoms of alcohol dependence such as tolerance development, withdrawal, craving and reduced control of alcohol intake can be explained by alcohol-induced alteration of dopaminergic neurotransmission and its GABAergic and glutamatergic modulation and their respective effects on pavlovian and operant conditioning as well as pavlovian-to-instrumental transfer. CONCLUSION Chronic alcohol intake impairs neurotransmitter systems that regulate prefrontal-striatal circuits and interfere with goal-directed decision-making and the acquisition of new, non-drug-related behavior patterns. Alcohol craving induced by pavlovian conditioned cues can facilitate habitual drug intake. Such learning mechanisms and their alterations by chronic alcohol intake might be targeted by specific interventions.
Collapse
Affiliation(s)
- Maria Garbusow
- Department of Psychiatry and Psychotherapy, Campus Charité Mitte, Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | | | | |
Collapse
|
15
|
Chohan TW, Nguyen A, Todd SM, Bennett MR, Callaghan P, Arnold JC. Partial genetic deletion of neuregulin 1 and adolescent stress interact to alter NMDA receptor binding in the medial prefrontal cortex. Front Behav Neurosci 2014; 8:298. [PMID: 25324742 PMCID: PMC4179617 DOI: 10.3389/fnbeh.2014.00298] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Accepted: 08/13/2014] [Indexed: 02/02/2023] Open
Abstract
Schizophrenia is thought to arise due to a complex interaction between genetic and environmental factors during early neurodevelopment. We have recently shown that partial genetic deletion of the schizophrenia susceptibility gene neuregulin 1 (Nrg1) and adolescent stress interact to disturb sensorimotor gating, neuroendocrine activity and dendritic morphology in mice. Both stress and Nrg1 may have converging effects upon N-methyl-D-aspartate receptors (NMDARs) which are implicated in the pathogenesis of schizophrenia, sensorimotor gating and dendritic spine plasticity. Using an identical repeated restraint stress paradigm to our previous study, here we determined NMDAR binding across various brain regions in adolescent Nrg1 heterozygous (HET) and wild-type (WT) mice using [3H] MK-801 autoradiography. Repeated restraint stress increased NMDAR binding in the ventral part of the lateral septum (LSV) and the dentate gyrus (DG) of the hippocampus irrespective of genotype. Partial genetic deletion of Nrg1 interacted with adolescent stress to promote an altered pattern of NMDAR binding in the infralimbic (IL) subregion of the medial prefrontal cortex. In the IL, whilst stress tended to increase NMDAR binding in WT mice, it decreased binding in Nrg1 HET mice. However, in the DG, stress selectively increased the expression of NMDAR binding in Nrg1 HET mice but not WT mice. These results demonstrate a Nrg1-stress interaction during adolescence on NMDAR binding in the medial prefrontal cortex.
Collapse
Affiliation(s)
- Tariq W Chohan
- The Brain and Mind Research Institute, University of Sydney Sydney, NSW, Australia ; Discipline of Pharmacology, School of Medical Science, University of Sydney Sydney, NSW, Australia
| | - An Nguyen
- The Brain and Mind Research Institute, University of Sydney Sydney, NSW, Australia ; ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation Sydney, NSW, Australia
| | - Stephanie M Todd
- The Brain and Mind Research Institute, University of Sydney Sydney, NSW, Australia ; Discipline of Pharmacology, School of Medical Science, University of Sydney Sydney, NSW, Australia
| | - Maxwell R Bennett
- The Brain and Mind Research Institute, University of Sydney Sydney, NSW, Australia
| | - Paul Callaghan
- The Brain and Mind Research Institute, University of Sydney Sydney, NSW, Australia ; ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation Sydney, NSW, Australia
| | - Jonathon C Arnold
- The Brain and Mind Research Institute, University of Sydney Sydney, NSW, Australia ; Discipline of Pharmacology, School of Medical Science, University of Sydney Sydney, NSW, Australia
| |
Collapse
|
16
|
Liu D, Hu L, Zhang J, Zhang P, Li S. Attenuated inhibition of medium spiny neurons participates in the pathogenesis of childhood depression. Neural Regen Res 2014; 9:1079-88. [PMID: 25206763 PMCID: PMC4146299 DOI: 10.4103/1673-5374.133171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2014] [Indexed: 11/04/2022] Open
Abstract
Accumulating evidence suggests that the nucleus accumbens, which is involved in mechanisms of reward and addiction, plays a role in the pathogenesis of depression and in the action of antidepressants. In the current study, intraperitoneal injection of nomifensine, a dopamine reuptake inhibitor, decreased depression-like behaviors in the Wistar Kyoto rat model of depression in the sucrose-preference and forced swim tests. Nomifensine also reduced membrane excitability in medium spiny neurons in the core of the nucleus accumbens in the childhood Wistar Kyoto rats as evaluated by electrophysiological recording. In addition, the expression of dopamine D2-like receptor mRNA was downregulated in the nucleus accumbens, striatum and hippocampus of nomifensine-treated childhood Wistar Kyoto rats. These experimental findings indicate that impaired inhibition of medium spiny neurons, mediated by dopamine D2-like receptors, may be involved in the formation of depression-like behavior in childhood Wistar Kyoto rats, and that nomifensine can alleviate depressive behaviors by reducing medium spiny neuron membrane excitability.
Collapse
Affiliation(s)
- Dandan Liu
- Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
| | - Linghan Hu
- Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
| | - Junqi Zhang
- Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
| | - Ping Zhang
- Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
| | - Shengtian Li
- Bio-X Institutes, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
17
|
Hu L, Yang J, Song T, Hou N, Liu Y, Zhao X, Zhang D, Wang L, Wang T, Huang C. A new stress model, a scream sound, alters learning and monoamine levels in rat brain. Physiol Behav 2013; 123:105-13. [PMID: 24096192 DOI: 10.1016/j.physbeh.2013.09.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 08/25/2013] [Accepted: 09/23/2013] [Indexed: 01/20/2023]
Abstract
Most existing animal models for stress involve the simultaneous application of physical and psychological stress factors. In the current study, we described and used a novel psychological stress model (scream sound stress). To study the validity of it, we carried out acute and chronic scream sound stress. First, adult Sprague-Dawley (SD) rats were randomly divided into white noise, stress and background groups. The white noise group and stress group were treated with white noise and scream sound for 4h in the morning respectively. Compared with white noise and background groups, exposure to acute scream sound increased corticosterone (CORT) level and decreased latency in Morris water maze (MWM) test. The levels of noradrenaline (NE), dopamine (DA), 5-hydroxytryptamine (5-HT), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were altered in the striatum, hypothalamus and hippocampus of stress rats. Second, adult SD rats were randomly divided into background and stress groups, which were treated with scream sound for three weeks. Exposure to chronic scream sound suppressed body weight gain, increased corticosterone (CORT) level, influenced the morphology of adrenal gland, improved spleen and thymus indices, and decreased latency in MWM test. NE, DA, DOPAC, HVA and 5-HIAA levels were also altered in the brain of stress rats. Our results suggested that scream sound, as a novel stressor, facilitated learning ability, as well as altered monoamine levels in the rat brain. Moreover, scream sound is easy to apply and can be applied in more animals at the same time.
Collapse
Affiliation(s)
- Lili Hu
- Department of Genetics and Molecular Biology, Xi'an Jiaotong University College of Medicine, Xi'an, Shaanxi, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Padival M, Quinette D, Rosenkranz JA. Effects of repeated stress on excitatory drive of basal amygdala neurons in vivo. Neuropsychopharmacology 2013; 38:1748-62. [PMID: 23535779 PMCID: PMC3717551 DOI: 10.1038/npp.2013.74] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Revised: 03/12/2013] [Accepted: 03/21/2013] [Indexed: 02/07/2023]
Abstract
Chronic stress leads to heightened affective behaviors, and can precipitate the emergence of depression and anxiety. These disorders are associated with increased amygdala activity. In animal models, chronic stress leads to increased amygdala-dependent behaviors, as well as hyperactivity of amygdala neurons. However, it is not known whether increased excitatory synaptic drive after chronic stress contributes to hyperactivity of basolateral amygdala (BLA; comprised of basal, lateral, and accessory basal nuclei) neurons. This study tested whether repeated stress causes an increase in excitatory drive of basal amygdala (BA) neurons in vivo, and whether this is correlated with an increase in the number of dendritic spines and a shift in dendritic distribution. Using in vivo intracellular recordings, this study found that repeated restraint stress caused an increase in the frequency of spontaneous excitatory synaptic events in vivo, which correlated with the number of dendritic spines in reconstructed neurons. Furthermore, parallel changes in the kinetics of the synaptic events and the distribution of spines indicated a more prominent functional contribution of synaptic inputs from across the dendritic tree. The shift in spine distribution across the dendritic tree was further confirmed with the examination of Golgi-stained tissue. This abnormal physiological drive of BA neurons after repeated stress may contribute to heightened affective responses after chronic stress. A reduction in the impact of excitatory drive in the BA may therefore be a potential treatment for the harmful effects of chronic stress in psychiatric disorders.
Collapse
Affiliation(s)
- Mallika Padival
- Department of Cellular and Molecular Pharmacology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - Danielle Quinette
- Department of Cellular and Molecular Pharmacology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
| | - J Amiel Rosenkranz
- Department of Cellular and Molecular Pharmacology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA,Department of Cellular and Molecular Pharmacology, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA, Tel: +1 847 578 8680, E-mail:
| |
Collapse
|
19
|
Influence of the novel histamine H₃ receptor antagonist ST1283 on voluntary alcohol consumption and ethanol-induced place preference in mice. Psychopharmacology (Berl) 2013; 228:85-95. [PMID: 23474889 DOI: 10.1007/s00213-013-3019-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 01/31/2013] [Indexed: 12/23/2022]
Abstract
RATIONALE Growing evidence supports a role for the central histaminergic system to have a modulatory influence on drug addiction in general and alcohol-use disorders in particular through histamine H3 receptors (H3R). OBJECTIVE In the present study, the effects of systemic injection of the newly synthesized H3R antagonist ST1283 on ethanol (EtOH) voluntary intake and EtOH-conditioned reward in mice have been investigated. METHODS Oral EtOH, saccharin, and quinine intake was assessed in a two-bottle choice paradigm using escalating concentrations of alcohol or tastant solutions. EtOH-induced place preference (CPP), EtOH-induced locomotor activity, and blood ethanol concentration (BEC) were also measured. RESULTS Following administration of the H3R antagonist (2.5, 5, and 10 mg/kg, i.p.), there was a significant dose-dependent decrease in alcohol consumption and preference. Importantly, vehicle- and ST1283 (5 mg/kg)-treated mice showed similar consumption and preference to increasing concentration of both sweet and bitter tastes. More interestingly, systemic administration of ST1283 inhibited EtOH-CPP and EtOH-enhanced locomotion. This inhibition was blocked when mice were pretreated with the selective H3R agonist R-(alpha)-methyl-histamine (10 mg/kg). Finally, vehicle- and ST1283-treated mice had similar BECs. CONCLUSION Our results show that ST1283 may decrease voluntary EtOH consumption and EtOH-CPP by altering its reinforcing effects, suggesting a novel role for histamine signaling in regulation of alcoholism. Lastly, the results add to the growing literature on H3R modulation in the pharmacotherapy of EtOH addiction.
Collapse
|
20
|
Prendergast MA, Mulholland PJ. Glucocorticoid and polyamine interactions in the plasticity of glutamatergic synapses that contribute to ethanol-associated dependence and neuronal injury. Addict Biol 2012; 17:209-23. [PMID: 21967628 PMCID: PMC3254017 DOI: 10.1111/j.1369-1600.2011.00375.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Stress contributes to the development of ethanol dependence and is also a consequence of dependence. However, the complexity of physiological interactions between activation of the hypothalamic-pituitary-adrenal (HPA) axis and ethanol itself is not well delineated. Emerging evidence derived from examination of corticotropin-releasing factor systems and glucocorticoid receptor systems in ethanol dependence suggests a role for pharmacological manipulation of the HPA axis in attenuating ethanol intake, though it is not clear how activation of the HPA axis may promote ethanol dependence or contribute to the neuroadaptative changes that accompany the development of dependence and the severity of ethanol withdrawal. This review examines the role that glucocorticoids, in particular, have in promoting ethanol-associated plasticity of glutamatergic synapses by influencing expression of endogenous linear polyamines and polyamine-sensitive polypeptide subunits of N-methyl-D-aspartate (NMDA)-type glutamate receptors. We provide evidence that interactions among glucocorticoid systems, polyamines and NMDA receptors are highly relevant to both the development of ethanol dependence and to behavioral and neuropathological sequelae associated with ethanol withdrawal. Examination of these issues is likely to be of critical importance not only in further elucidating the neurobiology of HPA axis dysregulation in ethanol dependence, but also with regard to identification of novel therapeutic targets that may be exploited in the treatment of ethanol dependence.
Collapse
Affiliation(s)
- Mark A. Prendergast
- University of Kentucky, Department of Psychology, 741 South Limestone Street, Lexington, KY 40536, U.S.A
- Spinal Cord and Brain Injury Research Center, B449 Biomedical and Biological Sciences Research Building, 741 South Limestone Street, Lexington, KY 40536, U.S.A
| | - Patrick J. Mulholland
- Departments of Neurosciences and Psychiatry & Behavioral Sciences, Medical University of South Carolina, 67 President Street, IOP 462 North Charleston, South Carolina 29425, U.S.A
| |
Collapse
|
21
|
Du X, Elberger AJ, Matthews DB, Hamre KM. Heterozygous deletion of NR1 subunit of the NMDA receptor alters ethanol-related behaviors and regional expression of NR2 subunits in the brain. Neurotoxicol Teratol 2011; 34:177-86. [PMID: 21945132 DOI: 10.1016/j.ntt.2011.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 09/02/2011] [Accepted: 09/06/2011] [Indexed: 02/07/2023]
Abstract
NMDA receptors have been hypothesized to play a role in various aspects of ethanol-related phenotypes, notably in ethanol withdrawal. However, the role of each of the specific subunits remains unclear. To address this issue, mice that are heterozygous for the NR1 deletion, and thus have a reduction in functional NMDA receptors, were examined for ethanol consumption and acute ethanol withdrawal. Additionally, mice were examined for the level of vocalization following footshock, and behavior in an elevated plus maze, to determine their responses to stress. In these behavioral tests, NR1 heterozygous mice were shown to consume significantly higher levels of ethanol in the two bottle-choice test showing a possible role for this receptor in ethanol consumption. Analysis of acute withdrawal found that the heterozygous mice exhibit lower levels of handling-induced convulsions consistent with a role in ethanol sensitivity or withdrawal. In contrast, no effects on stress-related phenotypes were detected. Levels of NR2A-NR2D subunits of the NMDA receptor in specific brain regions were compared between NR1+/- mice and wild-type controls to assess whether the behavioral responses were specific to the diminution in NR1 expression or whether these changes could be due to secondary changes in expression of other NMDA subunits. Real-time quantitative PCR, Western blot and immunohistochemistry were used to examine expression levels in the hippocampus, neocortex, striatum and cerebellum. For the majority of the subunits, no differences were found between the wild-type and heterozygous mice in any of the brain regions. However, the NR2B subunit exhibited differences in expression of RNA in the hippocampus and protein levels in multiple brain regions, between wild-type and NR1+/- mice. These results show that NR1 plays a role, through mechanisms as yet unknown, in the expression of NR2 subunits in a region and subtype specific manner. This provides evidence of the effects of altered levels of NR1 expression on ethanol withdrawal and consumption, and suggests that concomitant changes in the levels of NR2B may contribute to that effect.
Collapse
Affiliation(s)
- Xiaoping Du
- Department of Anatomy and Neurobiology, University of Tennessee, Health Science Center, 855 Monroe Avenue, Memphis, TN 38163, USA
| | | | | | | |
Collapse
|
22
|
Dagyte G, Luiten PG, De Jager T, Gabriel C, Mocaër E, Den Boer JA, Van der Zee EA. Chronic stress and antidepressant agomelatine induce region-specific changes in synapsin I expression in the rat brain. J Neurosci Res 2011; 89:1646-57. [PMID: 21688292 DOI: 10.1002/jnr.22697] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 04/18/2011] [Accepted: 04/18/2011] [Indexed: 12/17/2022]
Abstract
The antidepressant agomelatine acts as a melatonergic receptor (MT(1)/MT(2)) agonist and 5-HT(2C) receptor antagonist. Agomelatine has demonstrated efficacy in treating depression, but its neurobiological effects merit further investigation. Preclinical studies reported that agomelatine enhances adult hippocampal neurogenesis and increases expression of several neuroplasticity-associated molecules. Recently, we showed that agomelatine normalizes hippocampal neuronal activity and promotes neurogenesis in the stress-compromised brain. To characterize further the effects of this antidepressant in the stressed brain, here we investigated whether it induces changes in the expression of synapsin I (SynI), a regulator of synaptic transmission and plasticity. Adult male rats were subjected to daily footshock stress and agomelatine treatment for 3 weeks. Their brains were subsequently stained for total and phosphorylated SynI. Chronic footshock and agomelatine induced region-specific changes in SynI expression. Whereas chronic stress increased total SynI expression in all layers of the medial prefrontal cortex, agomelatine treatment abolished some of these effects. Furthermore, chronic agomelatine administration decreased total SynI expression in the hippocampal subregions of both stressed and nonstressed rats. Importantly, chronic stress decreased the fraction of phosphorylated SynI in all layers of the medial prefrontal cortex as well as selectively in the outer and middle molecular layers of the hippocampal dentate gyrus. These stress effects were at least partially abolished by agomelatine. Altogether, our data show that chronic stress and agomelatine treatment induce region-specific changes in SynI expression and its phosphorylation. Moreover, agomelatine partially counteracts the stress effects on SynI, suggesting a modulation of synaptic function by this antidepressant.
Collapse
Affiliation(s)
- Girstaute Dagyte
- Department of Molecular Neurobiology, University of Groningen, Groningen, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|