[Abstract Title]. - Society for Neuroscience

autonomic control in juvenile (i.e., 28-31 day old) male MS15 rats. Thus, these findings may
reflect an altered ability of the PVN to modulate autonomic outflow in response to stress in rats
with a developmental history of MS15.
Disclosures: L. Banihashemi , None; L. Rinaman, None.
Poster
281. Stress and the Brain: Early Life Experience I
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 281.27/OO7
Topic: E.06.e. Early life experience
Title: A potential gastrointestinal link between postnatal maternal care and adult anxiety
Authors: *L. M. RINAMAN, B. C. WEBER, H. N. MANFREDO;
Dept Neurosci, Univ. Pittsburgh, Pittsburgh, PA
Abstract: Previous studies have demonstrated that rat pups separated from their dam for 15
min/day (MS15) during the first two weeks postnatal display reduced anxiety-like behavior as
adults. MS15 increases the daily maternal care received by pups (e.g., licking/grooming, archedback
nursing), thereby promoting increased somatic and visceral sensory stimulation. Other
studies have shown that maternal reunion after separation increases plasma cholecystokinin
(CCK) levels in rat pups. Increased signaling at CCK-1 receptors activates gastrointestinal vagal
afferents, which could alter the development of central visceral circuits and thereby affect adult
anxiety responses. We hypothesized that concurrent CCK-1R blockade would reverse the
anxiolytic effects of MS15. To test this, rat pups were injected with devazepide (CCK-1R
antagonist; 2.3 nmol/100 nl s.c.), or with vehicle (5% DMSO, 5% Tween 80 in 0.15M NaCl), or
received no injection each day from P1-P10, in combination with MS15. Pups received no
further treatments after P10, and were weaned on P21. As young adults (~P50-60), rats were
tested for anxiety-like behavior in the EPMZ and in a novelty-suppressed feeding test. Compared
to results in non-separated control rats, MS15 reduced anxiety-like behavior in both behavioral
tests. The anxiolytic effects of MS15 were maintained in vehicle-injected MS15 rats, but were
reversed in devazepide-injected MS15 rats. Thus, the ability of MS15 to reduce later anxiety-like
behavior was eliminated by concurrent pharmacological blockade of CCK-1 receptors in rat
pups. We speculate that increased maternal care promotes increased CCK release from the gut
and increased vagal afferent signaling, and that this alters the developmental assembly of central
visceral circuits that impact adult emotionality and stress responsiveness.
Disclosures: L.M. Rinaman , None; B.C. Weber, None; H.N. Manfredo, None.