Olfactory deprivation and mating behavior in sexually experienced male cats

Abstract

The effects of bilateral olfactory bulbectomy (sodium pentobarbital anesthesia) upon mating behavior was studied in sexually experienced adult male cats. In the first experiment preoperative and postoperative behavior of eight animals were compared. After bulbectomy there were no decrements in mating behavior; rather, small but significant increases in sexual activity occurred, e.g., increased frequency and duration of intromission, decreased initial and intromissive mount latencies. A second experiment was designed to test the hypothesis that this increase in sexual activity resulted from a decrease in the amount of test time that the desensitized animals spent in related activities, especially sniffing. Here sniffing, grooming and scratching were measured in five bulbectomized and four sham operates. They were tested preoperatively, postoperatively in the usual test room and later in a strange test room. The same increase in sexual behavior appeared in the bulbectomized animals as in the first experiment. Additionally, there were significant decreases in frequency and duration of sniffing the room and sniffing the female. The sham operates remained unchanged. When tested in a strange room the shams reacted with a decrease in frequency of intromission and an increase in initial mount and intromissive mount latencies. Sniffing the room rose to well above preoperative levels. Under similar conditions the bulbectomized males showed some increase in frequency of intromission, increased latencies and an increase in sniffing of the room, but not to preoperative levels. The probability that complete anosmia was achieved in these experiments is supported by detailed histological examination of the brains which demonstrated that the glomeruli in remaining bulbar fragments were all markedly degenerate. Other important histological changes are described. The results are discussed in relation to the pronounced decrements following bulbectomy in several species of rodents.