[Abstract Title]. - Society for Neuroscience

Disclosures: R.S. Oosting , None; D. Meulendijks, None; T. Douma, None; E. Hendriksen,
None; M. Breuer, None; K. Westphal, None; B. Olivier, None.
Poster
255. Mood Disorders: Animal Models and Treatment Effects II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 255.21/Z2
Topic: C.15.h. Affective disorders: Animal models
Support: University of Vermont
Title: The 5-HT1A receptor antagonist WAY100635 dose-dependently decreases social
interaction when infused into the bed nucleus of the stria terminalis (BNST)
Authors: *K. M. RHODES, B. A. GRIMMIG, M. KOCHO-SCHELLENBERG, R. A.
SUGARMAN, M. R. WILLIAMS, S. E. HAMMACK;
Psychology, Univ. of Vermont, Burlington, VT
Abstract: Substantial evidence suggests that serotonin (5-HT) activation within the brain
modulates anxiety-like behavior. The bed nucleus of the stria terminalis (BNST) and
serotonergic caudal dorsal raphe nucleus (DRN) have both been argued to mediate anxiety-like
behavioral responding; hence, the activation of 5-HT neurons in the caudal DRN may modulate
anxiety-like behavior via the release of 5-HT within the BNST. BNST neurons exhibit a complex
response pattern to exogenous 5-HT, exhibiting both inhibitory and excitatory responses, which
are mediated by different 5-HT receptor subtypes. Prior studies suggest that the 5-HT1,7 receptor
agonist 5-carboxyamidotryptamine (5-CT) is anxiolytic, which is consistent with a reduction in
BNST activity mediated by 5-HT1A postsynaptic receptor activation. However the anxiolytic
effects of 5-CT could also be mediated by 5-HT7 receptor activation, due to high affinity of 5-
CT to this receptor subtype. To determine the effects of 5-HT1A receptor activation on anxietylike
behavior, we infused the 5-HT1A antagonist WAY-100635 (0, 0.04, 0.4 and 4 µg / 0.5 µl)
into the BNST of rats immediately before social interaction testing. In order to observe a
behavioral effect of the 5-HT1A antagonist against a background of elevated 5-HT, we
administered two 5-sec 1-mA footshocks immediately after infusion, because this treatment has
been shown to induce serotonin release in projection regions of the DRN. Rats were then tested
for social interaction in a different room and testing apparatus. Two animals receiving the same
drug treatment were placed into a testing box and social interaction was recorded for 10-min.
Pairs were scored for the total amount of time interacting (i.e. sniffing, boxing, following,
grooming, etc.) and locomotor activity (total number of line crosses). Social interaction was
defined as the amount of time interacting per line cross. WAY-100635 dose dependently