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Trace Amine-Associated Receptor 1 Contributes to Diverse Functional Actions of O-Phenyl-Iodotyramine in Mice but Not to the Effects of Monoamine-Based Antidepressants. Int J Mol Sci 2021; 22:ijms22168907. [PMID: 34445611 PMCID: PMC8396211 DOI: 10.3390/ijms22168907] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 12/29/2022] Open
Abstract
Trace Amine-Associated Receptor 1 (TAAR1) is a potential target for the treatment of depression and other CNS disorders. However, the precise functional roles of TAAR1 to the actions of clinically used antidepressants remains unclear. Herein, we addressed these issues employing the TAAR1 agonist, o-phenyl-iodotyramine (o-PIT), together with TAAR1-knockout (KO) mice. Irrespective of genotype, systemic administration of o-PIT led to a similar increase in mouse brain concentrations. Consistent with the observation of a high density of TAAR1 in the medial preoptic area, o-PIT-induced hypothermia was significantly reduced in TAAR1-KO mice. Furthermore, the inhibition of a prepulse inhibition response by o-PIT, as well as its induction of striatal tyrosine hydroxylase phosphorylation and elevation of extracellular DA in prefrontal cortex, were all reduced in TAAR1-KO compared to wildtype mice. O-PIT was active in both forced-swim and marble-burying tests, and its effects were significantly blunted in TAAR1-KO mice. Conversely, the actions on behaviour and prefrontal cortex dialysis of a broad suite of clinically used antidepressants were unaffected in TAAR1-KO mice. In conclusion, o-PIT is a useful tool for exploring the hypothermic and other functional antidepressant roles of TAAR1. By contrast, clinically used antidepressants do not require TAAR1 for expression of their antidepressant properties.
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Theise ND, Arment AR, Chakravarty D, Gregg JMH, Jacobson IM, Jung KH, Nair SS, Tewari AK, Thurston AW, Van Drie J, Westover JB. Clinical stage molecule PT150 is a modulator of glucocorticoid and androgen receptors with antiviral activity against SARS-CoV-2. Cell Cycle 2020; 19:3632-3638. [PMID: 33305659 PMCID: PMC7738205 DOI: 10.1080/15384101.2020.1859752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 01/20/2023] Open
Abstract
PT150 is a clinical-stage molecule, taken orally, with a strong safety profile having completed Phase 1 and Phase 2 clinical trials for its original use as an antidepressant. It has an active IND for COVID-19. Antiviral activities have been found for PT150 and other members of its class in a variety of virus families; thus, it was now tested against SARS-CoV-2 in human bronchial epithelial lining cells and showed effective 90% inhibitory antiviral concentration (EC90) of 5.55 µM. PT150 is a member of an extended platform of novel glucocorticoid receptor (GR) and androgen receptor (AR) modulating molecules. In vivo, their predominant net effect is one of systemic glucocorticoid antagonism, but they also show direct downregulation of AR and minor GR agonism at the cellular level. We hypothesize that anti-SARS-CoV-2 activity depends in part on this AR downregulation through diminished TMPRSS2 expression and modulation of ACE2 activity. Given that hypercortisolemia is now suggested to be a significant co-factor for COVID-19 progression, we also postulate an additive role for its potent immunomodulatory effects through systemic antagonism of cortisol.
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Affiliation(s)
- Neil D. Theise
- Department of Pathology, New York University-Grossman School of Medicine, New York, NY, USA
- Palisades Therapeutics/Pop Test Oncology LLC, Cliffside Park, NJ, USA
| | - Anthony R. Arment
- Department of Biology, Central State University, Wilberforce, OH, USA
| | - Dimple Chakravarty
- Department of Urology and the Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - John M. H. Gregg
- Palisades Therapeutics/Pop Test Oncology LLC, Cliffside Park, NJ, USA
| | - Ira M. Jacobson
- Department of Medicine, New York University-Grossman School of Medicine, New York, NY, USA
| | - Kie Hoon Jung
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT, USA
| | - Sujit S. Nair
- Department of Urology and the Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ashutosh K. Tewari
- Department of Urology and the Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | | | - Jonna B. Westover
- Department of Animal, Dairy, and Veterinary Sciences, Utah State University, Logan, UT, USA
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Dedic N, Kühne C, Gomes KS, Hartmann J, Ressler KJ, Schmidt MV, Deussing JM. Deletion of CRH From GABAergic Forebrain Neurons Promotes Stress Resilience and Dampens Stress-Induced Changes in Neuronal Activity. Front Neurosci 2019; 13:986. [PMID: 31619956 PMCID: PMC6763571 DOI: 10.3389/fnins.2019.00986] [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] [Received: 05/20/2019] [Accepted: 09/02/2019] [Indexed: 12/15/2022] Open
Abstract
Dysregulation of the corticotropin-releasing hormone (CRH) system has been implicated in stress-related psychopathologies such as depression and anxiety. Although most studies have linked CRH/CRH receptor 1 signaling to aversive, stress-like behavior, recent work has revealed a crucial role for distinct CRH circuits in maintaining positive emotional valence and appetitive responses under baseline conditions. Here we addressed whether deletion of CRH, specifically from GABAergic forebrain neurons (Crh CKO-GABA mice) differentially affects general behavior under baseline and chronic stress conditions. Expression mapping in Crh CK O-GABA mice revealed absence of Crh in GABAergic neurons of the cortex and limbic regions including the hippocampus, central nucleus of the amygdala and the bed nucleus of the stria terminals, but not in the paraventricular nucleus of hypothalamus. Consequently, conditional CRH knockout animals exhibited no alterations in circadian and stress-induced corticosterone release compared to controls. Under baseline conditions, absence of Crh from forebrain GABAergic neurons resulted in social interaction deficits but had no effect on other behavioral measures including locomotion, anxiety, immobility in the forced swim test, acoustic startle response and fear conditioning. Interestingly, following exposure to chronic social defeat stress, Crh CKO-GABA mice displayed a resilient phenotype, which was accompanied by a dampened, stress-induced expression of immediate early genes c-fos and zif268 in several brain regions. Collectively our data reveals the requirement of GABAergic CRH circuits in maintaining appropriate social behavior in naïve animals and further supports the ability of CRH to promote divergent behavioral states under baseline and severe stress conditions.
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Affiliation(s)
- Nina Dedic
- Molecular Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany.,Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA, United States
| | - Claudia Kühne
- Molecular Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - Karina S Gomes
- Molecular Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany.,Laboratory of Neuropsychopharmacology, Paulista State University, Araraquara, Brazil
| | - Jakob Hartmann
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA, United States.,Stress Resilience, Max Planck Institute of Psychiatry, Munich, Germany
| | - Kerry J Ressler
- Department of Psychiatry, Harvard Medical School and McLean Hospital, Belmont, MA, United States
| | - Mathias V Schmidt
- Stress Resilience, Max Planck Institute of Psychiatry, Munich, Germany
| | - Jan M Deussing
- Molecular Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
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Verdouw PM, van Esterik JC, Peeters BW, Millan MJ, Groenink L. CRF1 but not glucocorticoid receptor antagonists reduce separation-induced distress vocalizations in guinea pig pups and CRF overexpressing mouse pups. A combination study with paroxetine. Pharmacol Biochem Behav 2017; 154:11-19. [DOI: 10.1016/j.pbb.2017.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 01/04/2023]
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Overexpression of Forebrain CRH During Early Life Increases Trauma Susceptibility in Adulthood. Neuropsychopharmacology 2016; 41:1681-90. [PMID: 26538448 PMCID: PMC4832031 DOI: 10.1038/npp.2015.338] [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: 03/25/2015] [Revised: 09/30/2015] [Accepted: 10/29/2015] [Indexed: 01/02/2023]
Abstract
Although early-life stress is a significant risk factor for developing anxiety disorders, including posttraumatic stress disorder (PTSD), the underlying mechanisms are unclear. Corticotropin releasing hormone (CRH) is disrupted in individuals with PTSD and early-life stress and hence may mediate the effects of early-life stress on PTSD risk. We hypothesized that CRH hyper-signaling in the forebrain during early development is sufficient to increase response to trauma in adulthood. To test this hypothesis, we induced transient, forebrain-specific, CRH overexpression during early-life (pre-puberty, CRHOEdev) in double-mutant mice (Camk2a-rtta2 × tetO-Crh) and tested their behavioral and gene expression responses to the predator stress model of PTSD in adulthood. In one cohort of CRHOEdev exposed and unexposed mice, avoidance and arousal behaviors were examined 7-15 days after exposure to predator stress. In another cohort, gene expression changes in Crhr1, Crhr2, and Fkbp51 in forebrain of CRHOEdev exposed and unexposed mice were examined 7 days after predator stress. CRHOEdev induced robust increases in startle reactivity and reductions in startle inhibition independently of predator stress in both male and female mice. Avoidance behaviors after predator stress were highly dependent on sex and CRHOEdev exposure. Whereas stressed females exhibited robust avoidance responses that were not altered by CRHOEdev, males developed significant avoidance only when exposed to both CRHOEdev and stress. Quantitative real-time-PCR analysis indicated that CRHOEdev unexposed males exhibit significant changes in Crhr2 expression in the amygdala and bed nucleus stria terminalis in response to stress, whereas males exposed to CRHOEdev did not. Similar to CRHOEdev males, females exhibited no significant Crhr2 gene expression changes in response to stress. Cortical Fkbp51 expression was also significantly reduced by stress and CRHOEdev exposure in males, but not in females. These findings indicate that forebrain CRH hyper-signaling in early-life is sufficient to increase enduring effects of adult trauma and attenuate Crhr2 expression changes in response to stress in males. These data support growing evidence for significant sex differences in response to trauma, and support further study of CRHR2 as a candidate mechanism for PTSD risk.
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Rajbhandari AK, Baldo BA, Bakshi VP. Predator Stress-Induced CRF Release Causes Enduring Sensitization of Basolateral Amygdala Norepinephrine Systems that Promote PTSD-Like Startle Abnormalities. J Neurosci 2015; 35:14270-85. [PMID: 26490866 PMCID: PMC4683687 DOI: 10.1523/jneurosci.5080-14.2015] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 06/06/2015] [Accepted: 07/10/2015] [Indexed: 12/24/2022] Open
Abstract
The neurobiology of post-traumatic stress disorder (PTSD) remains unclear. Intense stress promotes PTSD, which has been associated with exaggerated startle and deficient sensorimotor gating. Here, we examined the long-term sequelae of a rodent model of traumatic stress (repeated predator exposure) on amygdala systems that modulate startle and prepulse inhibition (PPI), an operational measure of sensorimotor gating. We show in rodents that repeated psychogenic stress (predator) induces long-lasting sensitization of basolateral amygdala (BLA) noradrenergic (NE) receptors (α1) via a corticotropin-releasing factor receptor 1 (CRF-R1)-dependent mechanism, and that these CRF1 and NE α1 receptors are highly colocalized on presumptive excitatory output projection neurons of the BLA. A profile identical to that seen with predator exposure was produced in nonstressed rats by intra-BLA infusions of CRF (200 ng/0.5 μl), but not by repeated NE infusions (20 μg/0.5 μl). Infusions into the adjacent central nucleus of amygdala had no effect. Importantly, the predator stress- or CRF-induced sensitization of BLA manifested as heightened startle and PPI deficits in response to subsequent subthreshold NE system challenges (with intra-BLA infusions of 0.3 μg/0.5 μl NE), up to 1 month after stress. This profile of effects closely resembles aspects of PTSD. Hence, we reveal a discrete neural pathway mediating the enhancement of NE system function seen in PTSD, and we offer a model for characterizing potential new treatments that may work by modulating this BLA circuitry. SIGNIFICANCE STATEMENT The present findings reveal a novel and discrete neural substrate that could underlie certain core deficits (startle and prepulse inhibition) that are observed in post-traumatic stress disorder (PTSD). It is shown here that repeated exposure to a rodent model of traumatic stress (predator exposure) produces a long-lasting sensitization of basolateral amygdala noradrenergic substrates [via a corticotropin-releasing factor (CRF)-dependent mechanism] that regulate startle, which is exaggerated in PTSD. Moreover, it is demonstrated that the sensitized noradrenergic receptors colocalize with CRF1 receptors on output projection neurons of the basolateral amygdala. Hence, this stress-induced sensitization of noradrenergic receptors on basolateral nucleus efferents has wide-ranging implications for the numerous deleterious sequelae of trauma exposure that are seen in multiple psychiatric illnesses, including PTSD.
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Affiliation(s)
- Abha K Rajbhandari
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53719
| | - Brian A Baldo
- Department of Psychiatry and Neuroscience Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53719
| | - Vaishali P Bakshi
- Department of Psychiatry and Neuroscience Training Program, University of Wisconsin-Madison, Madison, Wisconsin 53719
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Flandreau E, Risbrough V, Lu A, Ableitner M, Geyer MA, Holsboer F, Deussing JM. Cell type-specific modifications of corticotropin-releasing factor (CRF) and its type 1 receptor (CRF1) on startle behavior and sensorimotor gating. Psychoneuroendocrinology 2015; 53:16-28. [PMID: 25575243 PMCID: PMC4364548 DOI: 10.1016/j.psyneuen.2014.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/25/2014] [Accepted: 12/03/2014] [Indexed: 10/24/2022]
Abstract
The corticotropin-releasing factor (CRF) family of peptides and receptors coordinates the mammalian endocrine, autonomic, and behavioral responses to stress. Excessive CRF production has been implicated in the etiology of stress-sensitive psychiatric disorders such as posttraumatic stress disorder (PTSD), which is associated with alterations in startle plasticity. The CRF family of peptides and receptors mediate acute startle response changes during stress, and chronic CRF activation can induce startle abnormalities. To determine what neural circuits modulate startle in response to chronic CRF activation, transgenic mice overexpressing CRF throughout the central nervous system (CNS; CRF-COE(CNS)) or restricted to inhibitory GABAergic neurons (CRF-COE(GABA)) were compared across multiple domains of startle plasticity. CRF overexpression throughout the CNS increased startle magnitude and reduced ability to inhibit startle (decreased habituation and decreased prepulse inhibition (PPI)), similar to previous reports of exogenous effects of CRF. Conversely, CRF overexpression confined to inhibitory neurons decreased startle magnitude but had no effect on inhibitory measures. Acute CRF receptor 1 (CRF1) antagonist treatment attenuated only the effects on startle induced by CNS-specific CRF overexpression. Specific deletion of CRF1 receptors from forebrain principal neurons failed to alter the effects of exogenous CRF or stress on startle, suggesting that these CRF1 expressing neurons are not required for CRF-induced changes in startle behaviors. These data indicate that the effects of CRF activation on startle behavior utilize an extensive neural circuit that includes both forebrain and non-forebrain regions. Furthermore, these findings suggest that the neural source of increased CRF release determines the startle phenotype elicited. It is conceivable that this may explain why disorders characterized by increased CRF in cerebrospinal fluid (e.g. PTSD and major depressive disorder) have distinct symptom profiles in terms of startle reactivity.
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Affiliation(s)
| | - Victoria Risbrough
- Veterans Administration Center of Excellence for Stress and Mental Health, 3350 La Jolla Village Drive San Diego, CA 92161, USA.
| | - Ailing Lu
- Unit of Innate Immunity, Key Laboratory of Molecular Virology and Immunology Institut Pasteur of Shanghai, Chinese Academy of Sciences. 320 Yue Yang Road, Shanghai, 200031; China. Phone/Fax: 86-21-54923102/54923101
| | - Martin Ableitner
- Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10 D-80804, Munich Phone: +49 (0)89 / 30622-645 Fax: +49 (0)89 / 30622-610
| | - Mark A Geyer
- Department of Psychiatry University of California San Diego 9500 Gilman Drive MC 0804 La Jolla, CA 92093-0804 ph (619)543-3582 fx (619)543-2493
| | - Florian Holsboer
- Max Planck Institute of Psychiatry Kraepelinstr. 2-10 80804 Munich, Germany Phone: +49-89-30622-220 Fax: +49-89-30622-483
| | - Jan M Deussing
- Department Stress Neurobiology and Neurogenetics Max Planck Institute of Psychiatry Kraepelinstrasse 2-10 D-80804, Munich Phone: +49 (0)89 / 30622-639 Fax: +49 (0)89 / 30622-610
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Toth M, Gresack JE, Bangasser DA, Plona Z, Valentino RJ, Flandreau EI, Mansuy IM, Merlo-Pich E, Geyer MA, Risbrough VB. Forebrain-specific CRF overproduction during development is sufficient to induce enduring anxiety and startle abnormalities in adult mice. Neuropsychopharmacology 2014; 39:1409-19. [PMID: 24326400 PMCID: PMC3988544 DOI: 10.1038/npp.2013.336] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/23/2013] [Accepted: 11/16/2013] [Indexed: 11/09/2022]
Abstract
Corticotropin releasing factor (CRF) regulates physiological and behavioral responses to stress. Trauma in early life or adulthood is associated with increased CRF in the cerebrospinal fluid and heightened anxiety. Genetic variance in CRF receptors is linked to altered risk for stress disorders. Thus, both heritable differences and environmentally induced changes in CRF neurotransmission across the lifespan may modulate anxiety traits. To test the hypothesis that CRF hypersignaling is sufficient to modify anxiety-related phenotypes (avoidance, startle, and conditioned fear), we induced transient forebrain-specific overexpression of CRF (CRFOE) in mice (1) during development to model early-life stress, (2) in adulthood to model adult-onset stress, or (3) across the entire postnatal lifespan to model heritable increases in CRF signaling. The consequences of these manipulations on CRF peptide levels and behavioral responses were examined in adulthood. We found that transient CRFOE during development decreased startle habituation and prepulse inhibition, and increased avoidance (particularly in females) recapitulating the behavioral effects of lifetime CRFOE despite lower CRF peptide levels at testing. In contrast, CRFOE limited to adulthood reduced contextual fear learning in females and increased startle reactivity in males but did not change avoidance or startle plasticity. These findings suggest that forebrain CRFOE limited to development is sufficient to induce enduring alterations in startle plasticity and anxiety, while forebrain CRFOE during adulthood results in a different phenotype profile. These findings suggest that startle circuits are particularly sensitive to forebrain CRFOE, and that the impact of CRFOE may be dependent on the time of exposure.
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Affiliation(s)
- Mate Toth
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA,Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla, CA, USA
| | - Jodi E Gresack
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA,Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY, USA
| | - Debra A Bangasser
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA,Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA, USA
| | - Zach Plona
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Rita J Valentino
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Isabelle M Mansuy
- Brain Research Institute, University and ETH Zürich, Zürich, Switzerland
| | - Emilio Merlo-Pich
- Neuroscience Disease Therapeutic Area, Pharmaceutical Division, F. Hoffman—La Roche, Basel, Switzerland
| | - Mark A Geyer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA,Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla, CA, USA
| | - Victoria B Risbrough
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA,Center of Excellence for Stress and Mental Health, Veterans Affairs Hospital, La Jolla, CA, USA,Department of Psychiatry, University of California San Diego, 9500 Gilman Drive MC0804, La Jolla CA 92093-0804, USA, Tel: +1 16195433582, Fax: +1 16195432475, E-mail:
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CRF1 receptor antagonists do not reverse pharmacological disruption of prepulse inhibition in rodents. Psychopharmacology (Berl) 2014; 231:1289-303. [PMID: 24186076 DOI: 10.1007/s00213-013-3315-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 10/04/2013] [Indexed: 10/26/2022]
Abstract
RATIONALE As enhanced corticotropin-releasing factor (CRF) transmission is associated with induction of sensorimotor gating deficits, CRF₁ receptor antagonists may reverse disrupted prepulse inhibition (PPI), an operational measure of sensorimotor gating. OBJECTIVES To determine the effects of CRF₁ receptor antagonists in pharmacological models of disrupted PPI and to determine if long-term elevated central CRF levels alter sensitivity towards PPI disrupting drugs. METHODS CP154,526 (10-40 mg/kg), SSR125543 (3-30 mg/kg) and DMP695 (40 mg/kg) were tested on PPI disruption provoked by D-amphetamine (2.5, 3 mg/kg), ketamine (5, 30 mg/kg) and MK801 (0.2, 0.5 mg/kg) in Wistar rats, C57Bl/6J and CD1 mice, and on spontaneously low PPI in Iffa Credo rats and DBA/2J mice. PPI-disrupting effects of D-amphetamine (2.5-5 mg/kg) and MK801 (0.3-1 mg/kg) were examined in CRF-overexpressing (CRFtg) mice, which display PPI deficits. Finally, we determined the influence of CP154,526 on D-amphetamine-induced dopamine outflow in nucleus accumbens and prefrontal cortex of CRFtg mice using in vivo microdialysis. RESULTS No CRF₁-antagonists improved PPI deficits in any test. CRFtg mice showed blunted PPI disruption in response to MK801, but not D-amphetamine. Further, D-amphetamine-induced dopamine release was less pronounced in CRFtg versus wild-type mice, a response normalized by pretreatment with CP154,526. CONCLUSION The inability of CRF₁ receptor antagonists to block pharmacological disruption of sensorimotor gating suggests that the involvement of CRF₁ receptors in the modulation of dopaminergic and glutamatergic neurotransmission relevant for sensory gating is limited. Furthermore, the alterations observed in CRFtg mice support the notion that long-term elevated central CRF levels induce changes in these neurotransmitter systems.
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TN D, MJ M, PM V, RS O, B O, L G. Valproate improves prepulse inhibition deficits induced by corticotropin-releasing factor independent of GABAA and GABAB receptor activation. Neuropharmacology 2014; 79:66-74. [DOI: 10.1016/j.neuropharm.2013.10.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 10/06/2013] [Accepted: 10/23/2013] [Indexed: 12/11/2022]
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Millan MJ. An epigenetic framework for neurodevelopmental disorders: from pathogenesis to potential therapy. Neuropharmacology 2012; 68:2-82. [PMID: 23246909 DOI: 10.1016/j.neuropharm.2012.11.015] [Citation(s) in RCA: 148] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 11/11/2012] [Accepted: 11/22/2012] [Indexed: 12/12/2022]
Abstract
Neurodevelopmental disorders (NDDs) are characterized by aberrant and delayed early-life development of the brain, leading to deficits in language, cognition, motor behaviour and other functional domains, often accompanied by somatic symptoms. Environmental factors like perinatal infection, malnutrition and trauma can increase the risk of the heterogeneous, multifactorial and polygenic disorders, autism and schizophrenia. Conversely, discrete genetic anomalies are involved in Down, Rett and Fragile X syndromes, tuberous sclerosis and neurofibromatosis, the less familiar Phelan-McDermid, Sotos, Kleefstra, Coffin-Lowry and "ATRX" syndromes, and the disorders of imprinting, Angelman and Prader-Willi syndromes. NDDs have been termed "synaptopathies" in reference to structural and functional disturbance of synaptic plasticity, several involve abnormal Ras-Kinase signalling ("rasopathies"), and many are characterized by disrupted cerebral connectivity and an imbalance between excitatory and inhibitory transmission. However, at a different level of integration, NDDs are accompanied by aberrant "epigenetic" regulation of processes critical for normal and orderly development of the brain. Epigenetics refers to potentially-heritable (by mitosis and/or meiosis) mechanisms controlling gene expression without changes in DNA sequence. In certain NDDs, prototypical epigenetic processes of DNA methylation and covalent histone marking are impacted. Conversely, others involve anomalies in chromatin-modelling, mRNA splicing/editing, mRNA translation, ribosome biogenesis and/or the regulatory actions of small nucleolar RNAs and micro-RNAs. Since epigenetic mechanisms are modifiable, this raises the hope of novel therapy, though questions remain concerning efficacy and safety. The above issues are critically surveyed in this review, which advocates a broad-based epigenetic framework for understanding and ultimately treating a diverse assemblage of NDDs ("epigenopathies") lying at the interface of genetic, developmental and environmental processes. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'.
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Affiliation(s)
- Mark J Millan
- Unit for Research and Discovery in Neuroscience, IDR Servier, 125 chemin de ronde, 78290 Croissy sur Seine, Paris, France.
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12
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Daskalakis NP, Oitzl MS, Schächinger H, Champagne DL, de Kloet ER. Testing the cumulative stress and mismatch hypotheses of psychopathology in a rat model of early-life adversity. Physiol Behav 2012; 106:707-21. [PMID: 22306534 DOI: 10.1016/j.physbeh.2012.01.015] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 12/27/2011] [Accepted: 01/20/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND In the present study, we tested both the cumulative stress and the mismatch hypothesis of psychopathology. For this purpose the combined effects of early-life adversity and later-life stress exposure on behavioral markers of psychosis susceptibility were studied in male Wistar rats. METHOD Experiment I: rat pups divided on the basis of the levels of their maternal care experience in low, medium or high maternal care groups, were reared post-weaning in groups (Exp. IA) or in social isolation (Exp. IB) and tested at adulthood under basal conditions or after an acute corticosterone (CORT) administration. Maternal care levels were assessed by measuring the dam's licking and grooming (LG) the first postnatal week of life. Experiment II: rat pups exposed as neonates to daily sessions of 8h of maternal separation (MS) on postnatal days 3, 4 and 5 either altogether in their home cage (HOME SEP) or alone in a novel environment (NOVEL SEP), were reared post-weaning in groups and tested at adulthood under basal conditions. Adult testing included behaviors marking psychosis susceptibility: apomorphine-induced gnawing (APO-gnawing), acoustic startle response and its modulation by a prepulse stimulus (PPI). The behavior of the Medium LG offspring was used as baseline reference for all the three experiments. RESULTS Experiment I: Low maternal LG history alone had limited effects on the behavior of Wistar offspring, although increased acoustic startle and increased PPI, at high prepulse intensity levels, were observed. When low maternal LG history was combined with post-weaning social isolation, basal APO-gnawing was decreased and PPI increased, compared to High LG and Med LG offspring. This reflects attenuated psychosis susceptibility. High LG offspring reared in isolation displayed, however, the highest APO-gnawing and the lowest PPI levels among rats reared in social isolation, which is indicative for increased psychosis susceptibility. These findings support the mismatch hypothesis. For demonstration of the cumulative stress hypothesis an injection of CORT in the adult Low LG offspring was required that increased APO-gnawing and reduced PPI. This CORT-induced PPI disruption was greatly enhanced after additional isolation rearing. The High LG group, either socially housed or reared in isolation, was resistant to the acute effects of CORT at adulthood. Experiment II: MS increased psychosis susceptibility only in NOVEL SEP rats that had experienced MS in the context of early social isolation. These individuals displayed increased adult APO-gnawing and reduced PPI, if reared post-weaning in a condition that does not match with their early life social environment (i.e. group housing). This finding supports the mismatch hypothesis. CONCLUSION The outcome of environmental manipulations on developmental programming of psychosis susceptibility depends on the interplay of early-life adversity and later-life stressors in a manner that supports the mismatch hypothesis. However, evidence for the cumulative stress hypothesis arises if vulnerable individuals are exposed in later life additionally to excess of the stress hormone CORT.
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Affiliation(s)
- Nikolaos P Daskalakis
- Division of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.
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13
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Vinkers CH, Hendriksen H, van Oorschot R, Cook JM, Rallipalli S, Huang S, Millan MJ, Olivier B, Groenink L. Lifelong CRF overproduction is associated with altered gene expression and sensitivity of discrete GABA(A) and mGlu receptor subtypes. Psychopharmacology (Berl) 2012; 219:897-908. [PMID: 21833506 PMCID: PMC3259347 DOI: 10.1007/s00213-011-2423-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2011] [Accepted: 07/15/2011] [Indexed: 12/22/2022]
Abstract
RATIONALE Repeated activation of corticotropin-releasing factor (CRF) receptors is associated with increased anxiety and enhanced stress responsivity, which may be mediated via limbic GABAergic and glutamatergic transmission. OBJECTIVE The present study investigated molecular and functional alterations in GABA(A) receptor (GABA(A)R) and metabotropic glutamate receptor (mGluR) responsivity in transgenic mice that chronically overexpress CRF. METHODS CRF(1) receptor, GABA(A)R, and mGluR sensitivity were determined in CRF-overexpressing mice using the stress-induced hyperthermia (SIH) test. In addition, we measured mRNA expression levels of GABA(A)R α subunits and mGluRs in the amygdala and hypothalamus. RESULTS CRF-overexpressing mice were less sensitive to the anxiolytic effects of the CRF(1) receptor antagonists CP154,526 and DMP695, the GABA(A)R α(3)-selective agonist TP003 (0-3 mg/kg) and the mGluR(2/3) agonist LY379268 (0-10 mg/kg) in the SIH test. The hypothermic effect of the non-selective GABA(A)R agonist diazepam (0-4 mg/kg) and the α(1)-subunit-selective GABA(A)R agonist zolpidem (0-10 mg/kg) was reduced in CRF-overexpressing mice. No genotype differences were found using the GABA(A)R α(5)-subunit preferential compound SH-053-2'F-R-CH(3) and mGluR(5) antagonists MPEP and MTEP. CRF-overexpressing mice showed decreased expression levels of GABA(A)R α(2) subunit and mGluR(3) mRNA levels in the amygdala, whereas these expression levels were increased in the hypothalamus. CRF-overexpressing mice also showed increased hypothalamic mRNA levels of α(1) and α(5) GABA(A)R subunits. CONCLUSIONS We found that lifelong CRF overproduction is associated with altered gene expression and reduced functional sensitivity of discrete GABA(A) and mGluR receptor subtypes. These findings suggest that sustained over-activation of cerebral CRF receptors may contribute to the development of altered stress-related behavior via modulation of GABAergic and glutamatergic transmission.
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Affiliation(s)
- Christiaan H Vinkers
- Division of Pharmacology, Utrecht Institute for Pharmaceutical Sciences and Rudolf Magnus Institute of Neuroscience, Utrecht University, Universiteitsweg 99, 3584CG Utrecht, The Netherlands.
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14
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Powell SB, Weber M, Geyer MA. Genetic models of sensorimotor gating: relevance to neuropsychiatric disorders. Curr Top Behav Neurosci 2012; 12:251-318. [PMID: 22367921 PMCID: PMC3357439 DOI: 10.1007/7854_2011_195] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Sensorimotor gating, or the ability of a sensory event to suppress a motor response, can be measured operationally via prepulse inhibition (PPI) of the startle response. PPI is deficient in schizophrenia patients as well as other neuropsychiatric disorders, can be measured across species, and has been used widely as a translational tool in preclinical neuropharmacological and genetic research. First developed to assess drug effects in pharmacological and developmental models, PPI has become one of the standard behavioral measures in genetic models of schizophrenia and other neuropsychiatric disorders that exhibit PPI deficits. In this chapter we review the literature on genetic models of sensorimotor gating and discuss the utility of PPI as a tool in phenotyping mutant mouse models. We highlight the approaches to genetic mouse models of neuropsychiatric disease, discuss some of the important caveats to these approaches, and provide a comprehensive table covering the more recent genetic models that have evaluated PPI.
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Affiliation(s)
- Susan B. Powell
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Martin Weber
- Department of Neuroscience, Genentech Inc, 1 DNA Way, South San Francisco, CA 94080-4990, USA
| | - Mark A. Geyer
- Department of Psychiatry, University of California San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0804, USA
- Research Service, VA San Diego Healthcare System, San Diego, CA, USA
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15
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Conti LH. Interactions between corticotropin-releasing factor and the serotonin 1A receptor system on acoustic startle amplitude and prepulse inhibition of the startle response in two rat strains. Neuropharmacology 2011; 62:256-63. [PMID: 21835187 DOI: 10.1016/j.neuropharm.2011.07.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 06/24/2011] [Accepted: 07/12/2011] [Indexed: 12/27/2022]
Abstract
Both the neuropeptide, corticotropin-releasing factor (CRF) and the serotonin 1A (5-HT(1A)) receptor systems have been implicated in anxiety disorders and there is evidence that the two systems interact with each other to affect behavior. Both systems have individually been shown to affect prepulse inhibition (PPI) of the acoustic startle response. PPI is a form of sensorimotor gating that is reduced in patients with anxiety disorders including post-traumatic stress and panic disorder. Here, we examined whether the two systems interact or counteract each other to affect acoustic startle amplitude, PPI and habituation of the startle response. In experiment 1, Brown Norway (BN) and Wistar-Kyoto (WKY) rats were administered ether an intraperitoneal (IP) injection of saline or the 5-HT(1A) receptor agonist, 8-OH-DPAT 10 min prior to receiving an intracerebroventricular (ICV) infusion of either saline or CRF (0.3 μg). In a second experiment, rats were administered either an IP injection of saline or the 5-HT(1A) receptor antagonist, WAY 100,635 10 min prior to receiving an ICV infusion of saline or CRF. Thirty min after the ICV infusion, the startle response and PPI were assessed. As we have previously shown, the dose of CRF used in these experiments reduced PPI in BN rats and had no effect on PPI in WKY rats. Administration of 8-OH-DPAT alone had no effect on PPI in either rat strain when the data from the two strains were examined separately. Administration of 8-OH-DPAT added to the effect of CRF in BN rats, and the combination of 8-OH-DPAT and CRF significantly reduced PPI in WKY rats. CRF alone had no effect on baseline startle amplitude in either rat strain, but CRF enhanced the 8-OH-DPAT-induced increase in startle in both strains. Administration of WAY 100,635 did not affect the CRF-induced change in PPI and there were no interactions between CRF and WAY 100,635 on baseline startle. The results suggest that activation of the 5-HT(1A) receptor can potentiate the effect of CRF on endophenotypes of anxiety disorders in animal models. This article is part of a Special Issue entitled 'Anxiety and Depression'.
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Affiliation(s)
- Lisa H Conti
- Department of Psychiatry, MC 1410, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06119, USA.
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16
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Douma TN, Kolarz A, Postma Y, Olivier B, Groenink L. The amphetamine-chlordiazepoxide mixture, a pharmacological screen for mood stabilizers, does not enhance amphetamine-induced disruption of prepulse inhibition. Behav Brain Res 2011; 225:377-81. [PMID: 21820012 DOI: 10.1016/j.bbr.2011.07.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 07/14/2011] [Accepted: 07/18/2011] [Indexed: 11/30/2022]
Abstract
In rodents, administration of a mixture of the psychostimulant d-amphetamine and the benzodiazepine chlordiazepoxide results in supra-additive hyperlocomotion, a phenomenon used to identify mood stabilizers. In an attempt to determine whether the d-amphetamine/chlordiazepoxide assay could extend to other behaviors that are affected in mania, we evaluated the effects of the mixture on prepulse inhibition. In addition, we combined chlordiazepoxide with the selective dopamine reuptake inhibitor GBR 12909 or the noradrenergic stimulant (-) ephedrine, and tested these alternative mixtures in locomotor activity and prepulse inhibition tests. Chlordiazepoxide (3mg/kg) robustly potentiated amphetamine-induced hyperactivity, but did not change the amphetamine-induced disruption of prepulse inhibition. This indicates that the d-amphetamine-chlordiazepoxide-induced hyperlocomotion does not extend to other dopamine-driven behaviors. GBR 12909 (16mg/kg) and (-) ephedrine (50mg/kg) both enhanced locomotor activity and disrupted PPI, but combined treatment of either of these compounds with chlordiazepoxide had no significant additive effect on locomotor activity or prepulse inhibition. These findings suggest that the effect of the d-amphetamine/chlordiazepoxide mixture cannot be accounted for by the dopamine enhancing properties of amphetamine alone. Last, valproic acid (120-240mg/kg) did not reduce the GBR-induced hyperactivity. Therefore, further pharmacological evaluation of GBR 12909-induced hyperactivity is warranted to determine its pharmacological potential to model mania-like behavior. Based on the current results, it is concluded that the utility of the pharmacological d-amphetamine/chlordiazepoxide assay as a tool to study brain mechanisms relevant to mania is limited.
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Affiliation(s)
- Tessa N Douma
- Department of Pharmacology, Utrecht Institute for Pharmaceutical Sciences and Rudolf Magnus Institute of Neuroscience, Utrecht University, Universiteitsweg 99, Utrecht, Netherlands.
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Prolonged and site-specific over-expression of corticotropin-releasing factor reveals differential roles for extended amygdala nuclei in emotional regulation. Mol Psychiatry 2011; 16:714-28. [PMID: 20548294 DOI: 10.1038/mp.2010.64] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Corticotropin-releasing factor (CRF) has a key role in the central stress response, and altered levels of this neuropeptide are linked to stress-related psychopathologies such as anxiety and depression. These disorders are associated with the inability to properly regulate stress response, specifically following exposure to prolonged stressful stimuli. Therefore, the current study assessed the effects of prolonged and site-specific over-expression of CRF, which mimics the state of chronic production, in extended amygdala nuclei that are known to be involved in mediating anxiety-like states. We first constructed and generated lentiviruses that overexpress (OE) CRF in a robust and stable manner, and then generated two male mouse models continuously over-expressing CRF, either at the central nucleus of the amygdala (CeA), or at the dorsolateral subdivision of the bed nucleus of the stria terminalis (BNSTdl). After 4 months, behavioral assessments were conducted for anxiety and depressive indices on these mice. Surprisingly, prolonged CRF OE at the CeA attenuated stress-induced anxiety-like behaviors, whereas prolonged CRF OE in the BNSTdl increased depressive-like behaviors, without affecting anxiety levels. These results show possible differential roles for CRF expressed by distinct loci of the extended amygdala, in mediating stress-induced emotional behaviors.
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Kasahara M, Groenink L, Kas MJ, Bijlsma EY, Olivier B, Sarnyai Z. Influence of transgenic corticotropin-releasing factor (CRF) over-expression on social recognition memory in mice. Behav Brain Res 2011; 218:357-62. [DOI: 10.1016/j.bbr.2010.12.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2010] [Revised: 12/14/2010] [Accepted: 12/20/2010] [Indexed: 10/18/2022]
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Bakshi VP, Alsene KM, Roseboom PH, Connors EE. Enduring sensorimotor gating abnormalities following predator exposure or corticotropin-releasing factor in rats: a model for PTSD-like information-processing deficits? Neuropharmacology 2011; 62:737-48. [PMID: 21288473 DOI: 10.1016/j.neuropharm.2011.01.040] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Revised: 01/23/2011] [Accepted: 01/24/2011] [Indexed: 01/21/2023]
Abstract
A deficit in prepulse inhibition (PPI) can be one of the clinically observed features of post-traumatic stress disorder (PTSD) that is seen long after the acute traumatic episode has terminated. Thus, reduced PPI may represent an enduring psychophysiological marker of this illness in some patients. PPI is an operational measure of sensorimotor gating and refers to the phenomenon in which a weak stimulus presented immediately before an intense startling stimulus inhibits the magnitude of the subsequent startle response. The effects of stress on PPI have been relatively understudied, and in particular, there is very little information on PPI effects of ethologically relevant psychological stressors. We aimed to develop a paradigm for evaluating stress-induced sensorimotor gating abnormalities by comparing the effects of a purely psychological stressor (predator exposure) to those of a nociceptive physical stressor (footshock) on PPI and baseline startle responses in rats over an extended period of time following stressor presentation. Male Sprague-Dawley rats were exposed (within a protective cage) to ferrets for 5 min or left in their homecage and then tested for PPI immediately, 24 h, 48 h, and 9 days after the exposure. The effects of footshock were evaluated in a separate set of rats. The effects seen with stressor presentation were compared to those elicited by corticotropin-releasing factor (CRF; 0.5 and 3 μg/6 μl, intracerebroventricularly). Finally, the effects of these stressors and CRF administration on plasma corticosterone were measured. PPI was disrupted 24 h after ferret exposure; in contrast, footshock failed to affect PPI at any time. CRF mimicked the predator stress profile, with the lowdose producing a PPI deficit 24 h after infusion. Interestingly, the high dose also produced a PPI deficit 24 h after infusion, but with this dose, the PPI deficit was evident even 9d later. Plasma corticosterone levels were elevated acutely (before PPI deficits emerged) by both stressors and CRF, but returned to normal control levels 24 h later, when PPI deficits were present. Thus, predator exposure produces a delayed disruption of PPI, and stimulation of CRF receptors recapitulates these effects. Contemporaneous HPA axis activation is neither necessary nor sufficient for these PPI deficits. These results indicate that predator exposure, perhaps acting through CRF, may model the delayed-onset and persistent sensorimotor gating abnormalities that have been observed clinically in PTSD, and that further studies using this model may shed insight on the mechanisms of information-processing deficits in this disorder. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
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Affiliation(s)
- Vaishali P Bakshi
- Department of Psychiatry and Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53719, USA.
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20
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Bijlsma E, van Leeuwen M, Westphal K, Olivier B, Groenink L. Local repeated corticotropin-releasing factor infusion exacerbates anxiety- and fear-related behavior: differential involvement of the basolateral amygdala and medial prefrontal cortex. Neuroscience 2011; 173:82-92. [DOI: 10.1016/j.neuroscience.2010.11.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Revised: 10/05/2010] [Accepted: 11/11/2010] [Indexed: 12/20/2022]
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Restraint stress-induced reduction in prepulse inhibition in Brown Norway rats: role of the CRF2 receptor. Neuropharmacology 2010; 60:561-71. [PMID: 21185316 DOI: 10.1016/j.neuropharm.2010.12.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 12/15/2010] [Accepted: 12/15/2010] [Indexed: 11/22/2022]
Abstract
Stress plays a role in many psychiatric disorders that are characterized by deficits in prepulse inhibition (PPI), a form of sensorimotor gating. Corticotropin-releasing factor (CRF) is one of the most important neurotransmitters involved in behavioral components of the stress response. Central infusion of CRF reduces PPI in both rats and mice. In mice, it has been shown that CRF(1) receptor activation mediates the effect of exogenous CRF on PPI. However, the roles of the two CRF receptors in a stress-induced reduction in PPI are not known. We sought to determine whether CRF(1) and/or CRF(2) receptor blockade attenuates a stress-induced reduction of PPI in rats. In separate experiments, we assessed PPI in Brown Norway rats after exposure to 5 days of 2-h restraint, and after pretreatment with the CRF(1) receptor antagonist, CP-154,526 (20.0 mg/kg), or the CRF(2) receptor antagonist, antisauvagine-30 (10.0 μg). Repeated, but not acute, restraint decreased PPI and attenuated the increase in PPI caused by repeated PPI testing. Blockade of the CRF(1) receptor did not attenuate the effect of repeated restraint on PPI or grooming behavior. While CRF(2) receptor blockade did attenuate the effect of repeated restraint on PPI, repeated ICV infusion of the selective CRF(2) receptor agonist urocortin III, did not affect PPI. These findings demonstrate the effect of stress on sensorimotor gating and suggest that the CRF(2) receptor mediates this effect in rats.
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Sutherland JE, Burian LC, Covault J, Conti LH. The effect of restraint stress on prepulse inhibition and on corticotropin-releasing factor (CRF) and CRF receptor gene expression in Wistar-Kyoto and Brown Norway rats. Pharmacol Biochem Behav 2010; 97:227-38. [PMID: 20709096 DOI: 10.1016/j.pbb.2010.08.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 07/24/2010] [Accepted: 08/07/2010] [Indexed: 10/19/2022]
Abstract
Stress plays a role in many psychiatric disorders that are characterized by deficits in prepulse inhibition (PPI), a form of sensorimotor gating. Corticotropin-releasing factor (CRF) is one of the most important neurotransmitters involved in behavioral components of the stress response, and central infusion of CRF decreases PPI in rodents. We recently demonstrated that restraint stress decreases PPI and attenuates the increase in PPI caused by repeated testing. To broaden our investigation into how restraint affects PPI, we subjected Wistar-Kyoto (WKY) and Brown Norway (BN) rats to 10 consecutive days of 2-hour restraint, or to brief handling, prior to assessing PPI. We next examined the effects of 1 or 10days of 2-hour restraint on plasma corticosterone levels in order to determine whether the endocrine response to stress parallels the behavioral effect of stress. Finally, we examined the effects of 1 or 10days of 2-hour restraint on CRF and CRF receptor gene expression in the amygdala, hippocampus, frontal cortex, and hypothalamus in order to determine whether a temporal pattern of gene expression parallels the change in the behavioral response to stress. The major findings of the present study are that 1) restraint stress attenuates the increase in PPI caused by repeated testing in both WKY and BN rats, and BN rats are more sensitive to the effects of restraint on PPI than WKY rats, 2) restraint-induced increases in corticosterone levels mirror the effect of restraint on PPI in WKY rats but not in BN rats, 3) laterality effects on gene expression were observed for the amygdala, whereby restraint increases CRF gene expression in the left, but not right, amygdala, and 4) some restraint-induced changes in CRF and CRF receptor gene expression precede changes in PPI while other changes coincide with altered PPI in a rat strain- and brain region-dependent manner.
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Affiliation(s)
- Jane E Sutherland
- Department of Psychiatry, University of Connecticut Health Center, Farmington, CT 06030, USA
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23
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Tejeda HA, Chefer VI, Zapata A, Shippenberg TS. The effects of kappa-opioid receptor ligands on prepulse inhibition and CRF-induced prepulse inhibition deficits in the rat. Psychopharmacology (Berl) 2010; 210:231-40. [PMID: 20232058 PMCID: PMC2946822 DOI: 10.1007/s00213-010-1799-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Accepted: 02/10/2010] [Indexed: 11/30/2022]
Abstract
RATIONALE Kappa-opioid receptor (KOR) agonists produce dysphoria and psychotomimesis in humans. KORs are enriched in the prefrontal cortex and other brain regions that regulate mood and cognitive function. Dysregulation of the dynorphin/KOR system has been implicated in the pathogenesis of schizophrenia, depression, and bipolar disorder. Prepulse inhibition of the acoustic startle reflex (PPI), a sensorimotor gating process, is disrupted in many psychiatric disorders. OBJECTIVES The present study determined whether KOR ligands alter PPI in rats. RESULTS Utilizing a range of doses of the synthetic KOR agonists (+/-) U50,488, (-) U50,488, and U69,593 and the naturally occurring KOR agonist, Salvinorin A, we demonstrate that KOR activation does not alter PPI or startle reactivity in rats. Similarly, selective KOR blockade using the long-acting antagonist nor-binaltorphimine (nor-BNI) was without effect. In contrast to KOR ligands, MK-801 and quinpirole produced deficits in PPI. Stress and corticotropin-releasing factor (CRF) decrease PPI levels. The dynorphin/KOR system has been suggested to be a key mediator of various behavioral effects produced by stress and CRF. We therefore examined the contribution of KORs to CRF-induced alterations in PPI. Intracerebroventricular infusion of CRF decreased PPI. Administration of nor-BNI failed to affect the CRF-evoked disruption in PPI. CONCLUSIONS Together, these results provide no evidence of a link between the dynorphin/KOR system and deficits in sensory gating processes. Additional studies, however, examining whether dysregulation of this opioid system contributes to cognitive deficits and other behavioral abnormalities associated with psychiatric disorders are warranted.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Animals
- Benzeneacetamides/pharmacology
- Corticotropin-Releasing Hormone/pharmacology
- Diterpenes, Clerodane/pharmacology
- Dose-Response Relationship, Drug
- Ligands
- Male
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Neural Inhibition
- Pyrrolidines/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Reflex, Startle/drug effects
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Affiliation(s)
- Hugo A. Tejeda
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, NIDA/IRP 333 Cassell Dr., Baltimore, MD 21224, USA
- Program in Neuroscience, University of Maryland, Baltimore, 20 Penn St., Baltimore, MD 21201, USA
| | - Vladimir I. Chefer
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, NIDA/IRP 333 Cassell Dr., Baltimore, MD 21224, USA
| | - Agustin Zapata
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, NIDA/IRP 333 Cassell Dr., Baltimore, MD 21224, USA
| | - Toni S. Shippenberg
- Integrative Neuroscience Section, Integrative Neuroscience Branch, National Institute on Drug Abuse, National Institutes of Health, NIDA/IRP 333 Cassell Dr., Baltimore, MD 21224, USA
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Conti LH, Sutherland JE, Muhlhauser CM. Interaction between the effects of corticotropin-releasing factor and prepulse parameters on prepulse inhibition in two inbred rat strains and the F1 generation of a cross between them. Behav Brain Res 2009; 200:165-72. [PMID: 19373982 DOI: 10.1016/j.bbr.2009.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Levels of prepulse inhibition (PPI) depend on the interval between the startling and prepulse stimuli. Brown Norway rats show less PPI of the acoustic startle response than Wistar-Kyoto (WKY) rats when the interval between the prepulse and startling stimulus is 100 ms. Central administration of corticotropin-releasing factor (CRF) decreases PPI at this inter-stimulus interval. Here, the effect of CRF on PPI over a range of inter-stimulus intervals was examined in WKY and BN rats, and in the F1 generation of a cross between them. Rats received an intracerebroventricular infusion of either saline or CRF 30 min prior to testing PPI. Test trials included startle stimulus alone trials, and trials on which a prepulse stimulus of either 6, 12, or 15 dB above background preceded the startling stimulus by either 20, 75, 100, 500 or 2000 ms. CRF decreased PPI in WKY rats at all inter-stimulus intervals and all prepulse intensities, while the effect of CRF on PPI in BN rats only occurred at intermediate intervals. BN and WKY rats showed different levels of PPI only at the intermediate intervals. Baseline PPI in the F1 rats resembled the WKY phenotype. The CRF-induced change in PPI in the F1 generation has some qualities of the effects in each of the progenitor strains. These results suggest that both the effect of rats strain and of CRF on PPI depend on the inter-stimulus interval, and that there is an interaction between prepulse stimulus intensity and the inter-stimulus interval.
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Affiliation(s)
- Lisa H Conti
- Department of Psychiatry and Neuroscience Program, University of Connecticut Health Center, 263 Farmington Ave., Farmington, CT 06030, USA.
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25
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Current world literature. Curr Opin Endocrinol Diabetes Obes 2009; 16:260-77. [PMID: 19390324 DOI: 10.1097/med.0b013e32832c937e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Decline in serotonergic firing activity and desensitization of 5-HT1A autoreceptors after chronic unpredictable stress. Eur Neuropsychopharmacol 2009; 19:215-28. [PMID: 19147333 DOI: 10.1016/j.euroneuro.2008.11.005] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 10/10/2008] [Accepted: 11/25/2008] [Indexed: 12/23/2022]
Abstract
Chronic stressful life events are risk factors for contracting depression, the pathophysiology of which is strongly associated with impairments in serotonergic (5-HT) neurotransmission. Indeed, in rodents, exposure to chronic unpredictable stress (CUS) produces depressive-like behaviours such as behavioural despair and anhedonia. To date, there have not been many studies that especially explore in vivo changes in 5-HT neurotransmission associated with CUS in the rat. Therefore, using in vivo electrophysiology, we evaluated whether CUS that induces anhedonia-like behaviours concurrently impairs midbrain raphe 5-HT neuronal activity. Unlike unstressed and acutely stressed rats, CUS produced progressive reductions in sucrose intake and preference (anhedonia-like). These were associated with a decrease in the spontaneous firing activity (35.4%) as well as in the number of spontaneously active 5-HT neurons, and a desensitization of somatodendritic 5-HT1A autoreceptors in the dorsal raphe. These results suggest that CUS dramatically decreases 5-HT neural activity and 5-HT1A autoreceptor sensitivity, and may represent endophenotypic features of depressive-like states.
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Bennett A O MR. Stress and anxiety in schizophrenia and depression: glucocorticoids, corticotropin-releasing hormone and synapse regression. Aust N Z J Psychiatry 2008; 42:995-1002. [PMID: 19016087 DOI: 10.1080/00048670802512073] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Stress during childhood and adolescence has implications for the extent of depression and psychotic disorders in maturity. Stressful events lead to the regression of synapses with the loss of synaptic spines and in some cases whole dendrites of pyramidal neurons in the prefrontal cortex, a process that leads to the malfunctioning of neural networks in the neocortex. Such stress often shows concomitant increases in the activity of the hypothalamic-pituitary-adrenal system, with a consequent elevated release of glucocorticoids such as cortisol as well as of corticotropin-releasing hormone (CRH) from neurons. It is very likely that it is these hormones, acting on neuronal and astrocyte glucocorticoid receptors (GRs) and CRH receptors, respectively, that are responsible for the regression of synapses. The mechanism of such regression involves the loss of synaptic spines, the stability of which is under the direct control of the activity of N-methyl-d-aspartate (NMDA) receptors on the spines. Glutamate activates NMDA receptors, which then, through parallel pathways, control the extent in the spine of the cytoskeletal protein F-actin and so spine stability and growth. Both GR and CRH receptors in the spines can modulate NMDA receptors, reducing their activation by glutamate and hence spine stability. In contrast, glucocorticoids, probably acting on nerve terminal and astrocyte GRs, can release glutamate, so promoting NMDA receptor activation. It is suggested that spine stability is under dual control by glucocorticoids and CRH, released during stress to change the stability of synaptic spines, leading to the malfunctioning of cortical neural networks that are involved in depression and psychoses.
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Affiliation(s)
- Maxwell R Bennett A O
- Brain and Mind Research Institute, University of Sydney, Camperdown, NSW, Australia.
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Swerdlow NR, Weber M, Qu Y, Light GA, Braff DL. Realistic expectations of prepulse inhibition in translational models for schizophrenia research. Psychopharmacology (Berl) 2008; 199:331-88. [PMID: 18568339 PMCID: PMC2771731 DOI: 10.1007/s00213-008-1072-4] [Citation(s) in RCA: 415] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Accepted: 01/03/2008] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Under specific conditions, a weak lead stimulus, or "prepulse", can inhibit the startling effects of a subsequent intense abrupt stimulus. This startle-inhibiting effect of the prepulse, termed "prepulse inhibition" (PPI), is widely used in translational models to understand the biology of brainbased inhibitory mechanisms and their deficiency in neuropsychiatric disorders. In 1981, four published reports with "prepulse inhibition" as an index term were listed on Medline; over the past 5 years, new published Medline reports with "prepulse inhibition" as an index term have appeared at a rate exceeding once every 2.7 days (n=678). Most of these reports focus on the use of PPI in translational models of impaired sensorimotor gating in schizophrenia. This rapid expansion and broad application of PPI as a tool for understanding schizophrenia has, at times, outpaced critical thinking and falsifiable hypotheses about the relative strengths vs. limitations of this measure. OBJECTIVES This review enumerates the realistic expectations for PPI in translational models for schizophrenia research, and provides cautionary notes for the future applications of this important research tool. CONCLUSION In humans, PPI is not "diagnostic"; levels of PPI do not predict clinical course, specific symptoms, or individual medication responses. In preclinical studies, PPI is valuable for evaluating models or model organisms relevant to schizophrenia, "mapping" neural substrates of deficient PPI in schizophrenia, and advancing the discovery and development of novel therapeutics. Across species, PPI is a reliable, robust quantitative phenotype that is useful for probing the neurobiology and genetics of gating deficits in schizophrenia.
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Affiliation(s)
- Neal R Swerdlow
- Department of Psychiatry, UCSD School of Medicine, La Jolla, CA, 92093-0804, USA,
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