Differential Localization of a Male and a Female Hypothalamic Mating Centre

Abstract

Implantation of testosterone propionate (tp) in the pre-optic-anterior hypothalamic region produced predominantly male, i.e. homosexual behaviour in female spayed rats. On the other hand, tp implants in the central hypothalamus induced mainly female behaviour, as did subcutaneous tp injections in these animals (D\l=o"\rner, D\l=o"\cke& Moustafa, 1968). Therefore, it was assumed that two different hypothalamic mating centres are responsible for the male and female mating activity. In the following study this hypothesis was reinvestigated by means of intra-hypothalamic implantations of oestradiol benzoate (ob) in rats.Precise quantities of crystalline ob were implanted stereotaxically into the anterior or central hypothalamus of post-puberally spayed female rats of the Sprague-Dawley strain. The stereotaxic implantations were performed according to a method described recently (D\l=o"\cke, D\l=o"\rner& Voigt, 1968). ob was dissolved in alcohol, the solution was aspirated into calibrated glass capillary tubes, and the hormone was implanted after evaporation of the alcohol and recrystallization. The implants were introduced bilaterally anterior or posterior to the bregma according to the stereotaxic atlas of Szent\l=a'\gothai,Flerk\l=o'\, Mess & Hal\l=a'\sz (1968) (A 0\m=.\5for implantations in the anterior and P 2\m=.\5in the central (middle) hypothalamus). After autopsy each hypothalamus was frozen, serially sectioned at 15 \g=m\ and stained with haematoxylin and eosin to verify the exact localization of the implants.Tests for sexual behaviour were performed on Days 3, 5 and 7 following the implantation. In the mating tests each rat was exposed for 5 min to (1) a vigorous male, and (2) an oestrous female (Dörner, 1967). Animals with intra¬ hypothalamic cholesterol implants or subcutaneous ob implants served as

Effects of hypothalamic deafferentation on hormonal facilitation of lordosis in in ovariectomized rats.

“…This is well consistent with a recent concept proposed by several investigators (Dorner et al, 1968;Mathews and Edwards, 1977;Malsbury et al, 1977;Barfield and Chen, 1977) that the VM plays an important role in the hormonal induction of lordosis behavior. In this context, the effect of the AD-I and MBHisland could be interpreted to interrupt the neural pathways involved in lordosis facilitation entering or leaving anterolaterally the VM region.…”

Brain response to putative pheromones in lesbian women

“…These signals are processed by specific nuclei located in the anterior hypothalamus, identified as male and female mating centers (1)(2)(3)(4)(5). A lesion of the respective mating center as well as impairment of pheromone transduction may alter the coital approach in a sex-specific way (3)(4)(5).…”

Common Hypothalamic Sites for Activation of Sexual Receptivity in Female Rats by LHRH, PGE₂ and Progesterone

“…Lesions of the MBH have been shown to inhibit sexual behavior in female rats [5,6,17,20], while lesions of the POA result in facilitation of sexual responsiveness in female rats and guinea pigs [30. 34],…”