Steroidal influences on pup-killing behavior in mice

Four experiments were conducted in order to examine the biochemical pathway through which testosterone (T) acts to produce pup-killing behavior in ovariectomized female mice. Estradiol benzoate (EB) and testosterone propionate (TP) were both effective in stimulating the pup-killing response (Experiment 1). The nonaromatizable androgen dihydrotestosterone (DHT) and the aromatizable androgen testosterone (T) were equipotent in eliciting the behavior while the nonaromatizable androgen androstanedione (AA) was ineffective (Experiment 2). Pup-killing behavior was activated by the aromatizable androgen androstenedione (AE) but only if it was administered chronically at very high doses (Experiment 3). The combination of subthreshold doses of EB and DHT synergized to produce the pup-killing response (Experiment 4). These findings suggest that both aromatization and reduction may be important for the stimulation of pup-killing behavior in mice.