[Abstract Title]. - Society for Neuroscience

Disclosures: I. Bantounas, None; Y. Lee, None; J.L. Howarth, None; P. Verkade, None; J.B.
Uney, None.
Poster
283. Stress-Regulated Pathways II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 283.16/PP12
Topic: E.06.f. Stress modulated pathways
Support: NARSAD Young Investigator Award (IAK)
Pritzker Neuropsychiatric Disorders Research Consortium (SJW)
NIDA 5P01DA021633-02 (HA & SJW)
Office of Naval Research N00014-02-1-0879 (HA & SJW)
Title: Are emotional-somatomotor circuits modifiable by exposure to increased environmental
complexity?
Authors: *S. M. CLINTON, I. A. KERMAN, P. R. BURGHARDT, A. D. ABRAHAM, T. A.
BEDROSIAN, H. ORR, N. VACHHANI, N. MUZAMHINDO, C. SHABRANG, J. BEALS, S.
J. WATSON, H. AKIL;
Molec & Behav Neurosci Inst., Univ. Michigan, Ann Arbor, MI
Abstract: Exposure to increasing environmental complexity (EC) has the potential to diminish
depressive- and anxiety- like behaviors in rodents. The current study sought to determine
whether such manipulation may also alter the organization of emotional-somatomotor circuits
which likely mediate these behaviors. We recently found altered organization of such circuits in
the Low Responder (LR) rat model of co-morbid depression and anxiety. When compared to
their High Responder (HR) counterparts, LR rats exhibit increased depressive- and anxiety- like
behaviors on a variety of assays and also contain fewer neurons in the paraventricular nucleus of
the hypothalamus (PVN) with poly-synaptic projections to skeletal muscle (but not to the adrenal
gland). To determine whether these HR/LR behavioral and associated anatomical differences
may be reversible, we exposed LR rats to 4 weeks of increased EC. A group of LR rats (N=12)
was housed from postnatal day (P)25 to P53 (28 days total) in a 3‟ x 3‟ x 3‟ wire mesh cage that
contained different toys and obstacle courses. Animals were free to explore within this
environment, and its complexity was increased by a daily addition of a novel object until the
final day (P53) when the environment reached its maximum complexity. Control HR and LR rats