An increase in dendritic arborization of pyramidal neurons in the CA3 hippocampal subfield has previously been noted two months following gonadectomy (GDX). This expansion may occur sooner than two months, as GDX is associated with increased brain derived neurotrophic factor (BDNF) protein two weeks following GDX. Pyramidal neuron morphology in areas anatomically connected to the hippocampus such as LII/III of the medial prefrontal cortex may also be altered at ten days. We hypothesized CA3 and LII/III neurons in the male rat hippocampus will undergo expansion ten days following GDX, and changes in BDNF protein levels will be present. GDX resulted in dendritic expansion, SHAM surgery resulted in dendritic atrophy and testosterone replacement blocked GDX or SHAM surgery-induced dendritic remodelling in CA3 and LII/III pyramidal neurons. BDNF levels were highest in CA3 of SHAM operated animals. These findings may contribute to the mixed effects of androgen deprivation on cognition and memory.