Fear extinction forms a new memory but does not erase the original fear memory. Exposure to novelty facilitates transfer of short-term extinction memory to long-lasting memory. However, the underlying cellular and molecular mechanisms are still unclear. Using a classical contextual fear-conditioning model, we investigated the effect of novelty on long-lasting extinction memory in rats. We found...

A diurnal change of tuberoinfundibular dopaminergic (TIDA) neuronal activity exists in female rats, which is prerequisite for the estrogen-induced afternoon PRL surge. Because progesterone (P4) administered in the morning can advance and amplify the PRL surge, it is of interest to learn whether its action involves the TIDA neuron. In adult ovariectomized and estrogen-primed Sprague-Dawley rats,...