Many affective disorders are caused or exacerbated by exposure to severe or repeated stressors. Despite the important role of stressor exposure in modulating emotion, the mechanisms by which central emotional circuits are altered by stress are still unknown. Substantial evidence has suggested that the bed nucleus of the strain terminalis (BNST) mediates anxiety-like behavior in humans and animals, and it is likely that altered BNST function underlies anxiety disorders. In addition to coordinating anxiety-like behavioral responses, the BNST also organizes stress responding via projections to the paraventricular nucleus of the hypothalamus (PVN). We now have substantial data suggested that pituitary adenylate cyclase activating polypeptide (PACAP) activation and release in the BNST mediates many of the behavioral effects of repeated stress, since BNST PACAP antagonism blocks the behavioral consequences of repeated stress, BNST PACAP infusion mimics many of these behavioral consequences, and repeated stress or glucocorticoid treatment substantially elevates BNST PACAP in rats. Moreover, we have also recently shown that circulating PACAP levels and a unique single nucleotide polymorphism in the PAC1 receptor predict PTSD symptoms and diagnosis in women, suggesting that PACAP systems are indeed altered in anxiety disorders. Hence, the Aims of this proposal were designed to investigate mechanisms by which PACAP may modulate BNST activity, whether these mechanisms differ in male and female rats, and whether these differences depend on estrogen.
Aim 1 will characterize the anatomy of different BNST subregions that potentially underlie the effects of BNST PACAP activation by stress.
Aim 2 will investigate mechanisms by which PACAP can enhance the excitability of BNST neurons.
Aim 3 will investigate the role of PACA in stress-induce enhancement in BNST neuroplasticity.
Aim 4 will investigate sex difference in BNST PACAP circuitry and the dependence on estrogen. These studies will investigate mechanisms by which PACAP, a peptide only recently implicated in stress-related psychopathology, might mediate emotional behavior, by enhancing excitability and plasticity in a brain region critical for anxiety-like behavior, the BNST.

Public Health Relevance

Many affective disorders in humans result from exposure to environmental stressors. However, the mechanisms by which stressor exposure modulates the central nervous system to produce pathological emotional states are still unknown. We have implicated central pituitary adenylate cyclase activating polypeptide (PACAP) as a critical mediator of the effects of stressor exposure on emotion. The studies in this proposal investigate mechanisms by which PACAP may modulate activity in brain regions associated with anxiety, and how these mechanisms may differ in males and females.

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Project (R01)
Project #
5R01MH097988-02
Application #
8475664
Study Section
Neurobiology of Motivated Behavior Study Section (NMB)
Program Officer
Desmond, Nancy L
Project Start
2012-05-29
Project End
2017-04-30
Budget Start
2013-05-01
Budget End
2014-04-30
Support Year
2
Fiscal Year
2013
Total Cost
$366,000
Indirect Cost
$126,000
Name
University of Vermont & St Agric College
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
066811191
City
Burlington
State
VT
Country
United States
Zip Code
05405
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Lezak, Kimberly R; Roman, Carolyn W; Braas, Karen M et al. (2014) Regulation of bed nucleus of the stria terminalis PACAP expression by stress and corticosterone. J Mol Neurosci 54:477-84
Kocho-Schellenberg, Margaret; Lezak, Kimberly R; Harris, Olivia M et al. (2014) PACAP in the BNST produces anorexia and weight loss in male and female rats. Neuropsychopharmacology 39:1614-23
Lezak, K R; Roelke, E; Harris, O M et al. (2014) Pituitary adenylate cyclase-activating polypeptide (PACAP) in the bed nucleus of the stria terminalis (BNST) increases corticosterone in male and female rats. Psychoneuroendocrinology 45:11-20
May, Victor; Clason, Todd A; Buttolph, Thomas R et al. (2014) Calcium influx, but not intracellular calcium release, supports PACAP-mediated ERK activation in HEK PAC1 receptor cells. J Mol Neurosci 54:342-50
Longden, Thomas A; Dabertrand, Fabrice; Hill-Eubanks, David C et al. (2014) Stress-induced glucocorticoid signaling remodels neurovascular coupling through impairment of cerebrovascular inwardly rectifying K+ channel function. Proc Natl Acad Sci U S A 111:7462-7
Missig, Galen; Roman, Carolyn W; Vizzard, Margaret A et al. (2014) Parabrachial nucleus (PBn) pituitary adenylate cyclase activating polypeptide (PACAP) signaling in the amygdala: implication for the sensory and behavioral effects of pain. Neuropharmacology 86:38-48
Roman, Carolyn W; Lezak, Kim R; Hartsock, Matthew J et al. (2014) PAC1 receptor antagonism in the bed nucleus of the stria terminalis (BNST) attenuates the endocrine and behavioral consequences of chronic stress. Psychoneuroendocrinology 47:151-65