Smell as an Exteroceptive Factor

Abstract

The pathways by which olfactorily-induced exteroceptive effects are mediated are unknown. In the sow at any rate a direct link between the liberation of pituitary gonadotropins and the olfactory lobes has been established (Signoret and Mauleon, 1962). The hypothalamus must be involved. In mice the stimulus causing the block to implantation depends upon the inhibition of prolactin secretion, while the effect of the male on oestrus depends on the evocation of FSH secretion. Hypothalamic activity simultaneously promotes FSH secretion and depresses the secretion of prolactin, so that the effects both on oestrus and on pregnancy can be explained on the assumption that the hypothalamus is stimulated by the odour of males. On the other hand, as prolactin is under constant restraint by the hypothalamus, the suppression of oestrus and the increase in the production of prolactin which accompanies olfactory stimulation derived from females implies a depression of hypothalamic activity. Copyright © 1966. American Society of Animal Science. Copyright 1966 by American Society of Animal Science