Summary
In two separate and independent experimental series it was studied, whether 8-arginine-vasopressin
(AVP) or 8-lysine-vasopressin (LVP) administered daily in μg amounts to pregnant rats,
and/or to their offspring postnatally for 30 days, induce alterations that can be
registered by a behavioral test. The realization of the test used, a foot-shock motivated
brightness discrimination (BD) reaction, includes learning and memory processes. There
is one general result of the two experimental series, which include 263 rats divided
up in different combinations of pretreatment. Vasopressin (VP), AVP or LVP, pre- and
postnatally administered, induces a significantly improved BD performance of approximately
40%, compared to the control groups. The improvement is detectable in different ages
of the offspring, in females as well as in males. A smaller though also significant
improvement was observed when AVP or LVP was injected only postnatally. The critical
period in which the pep tides are able to induce the alterations measured probably
includes prenatal and postnatal periods in the lifes of the rats. What molecular interactions
actually underly the improved behavioral performance remain to be clarified.
Key words
Vasopressin - Learning - Brain development
