[Abstract Title]. - Society for Neuroscience

Support: NIH Grant 2 P20 RR015567-07
Title: Role of early life stress on anxiety-like behavior in adolescence
Authors: *K. E. TSCHETTER 1 , L. B. CALLAHAN 3 , P. J. RONAN 2,3 ;
1 Basic Biomed Sci., 2 Neurosci., Univ. South Dakota Sch. Med., Sioux Falls, SD; 3 Brain Res.,
Avera Res. Inst., Sioux Falls, SD
Abstract: It is well known that stress is a primary factor driving both acquisition and
maintenance of addictive behaviors. Early life stress is a risk factor for increased vulnerability to
drug addiction during the particularly vulnerable period of adolescence. Addictive behaviors that
develop during adolescence often persist into adulthood. Maternal separation (MS) is a widely
used animal model of early life stress. Very few studies have evaluated the effects of MS on
brain stress systems during adolescence. In this experiment we sought to evaluate the effects of
MS on the expression of CRF receptors and anxiety-like behavior during adolescence. Rats
experiencing maternal separation were removed from the dam once a day, for postnatal days
(PND) 2-14, with the separation lasting either 15 minutes (MS15) or 180 minutes (MS180). We
utilized two control groups; animal facility raised (AFR), which received twice weekly cage
changes with no other separation, and non-handled (NH) which received no cage changes except
on PND11 and no separation. Beginning on PND15 all groups received twice weekly cage
changes. Pups were weaned on PND21-22. Rats were then allowed to mature to periadolescence
(PND40) before testing for anxiety-like behavior on the elevated plus maze (EPM). Females
exposed to MS spent less time on the open arms when compared to the controls. Males exposed
to AFR and MS180 conditions showed a decrease in percent time spent on the open arms when
compared to NH and MS15. There were no significant differences in the total distance moved
(cm) between any groups. These results demonstrate that early life stress affects anxiety-like
behavior during adolescence. We also used a microdissection technique coupled with
quantitative immunoblotting to determine the effects of MS on components of the corticotropin
releasing factor (CRF) system; one of the key stress-coordinating systems in brain. Females
exposed to MS180 showed an upregulation of CRF1, CRF2, and CRF-BP in the nucleus
accumbens (NAc) compared to controls. Females exposed to MS180 also showed an
upregulation of CRF-BP in the bed nucleus of the stria terminalis (BNST).
Disclosures: K.E. Tschetter , None; L.B. Callahan, None; P.J. Ronan, None.
Poster
281. Stress and the Brain: Early Life Experience I
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 281.5/NN19