A thyroid hormone-vasopressin interaction promotes survival and maturation of hippocampal neurons dissociated postnatally.

Hippocampal cells dissociated from 5-day-old rat pups were grown in a suitable chemically defined basal medium, supplemented or not with 3,3',5-triiodo-L-thyronine (T3), [Arg8]-vasopressin (AVP), or both, at different concentrations. Four days after plating, neuron-like cells began to degenerate drastically in the basal medium. Although AVP alone had no effect, T3, and to a greater extent T3 and AVP together, prevented their death. Moreover, T3 and AVP also acted synergically in promoting the maturation of surviving cells, especially AchE-positive neurons, either directly or through glial cells.