Brain-derived neurotrophic factor (BDNF), by virtue of its relationship to various neurotransmitter systems, hormones, and to estrogen in particular, may play a role in maternal behavior. To explore this possible role, female virgin Sprague Dawley rats received continuous intracerebroventricular infusions ofBDNF sense oligonucleotide and were exposed to pups for maternal behavior testing. Behaviorally, BDNF sense had no effect on maternal behavior but did significantly suppress pup attacks during the first 24 hours of exposure. BDNF had a significant effect on neuronal morphology in the medial preoptic area (mPOA) as well, such that neurons in this region exposed to BDNF had more dendritic protrusions per 10 μm of dendritic branch than did control neurons. However, the length of the two longest dendritic spines on each branch measured was not affected. These findings shed light on the differential effects of BDNF in both priming the mPOA for behavior to occur, and in suppressing a specific aspect of maternal behavior
