Autoradiographic Localization of Estradiol-Concentrating Cells in the Female Hamster Brain

Abstract

Autoradiographic methods were used to study the location of estrogen-concentrating cells in the brain of the female hamster. In the hypothalamus, well-labelled cells were reliably found in the posterior medial preoptic area (MPOA), the anterior hypothalamus (AHA), and the ventromedial (VM), arcuate (ARC) and ventral premammillary nuclei (VPM). In the limbic system, well-labelled cells were found in the ventro-lateral septum, bed nucleus of the stria terminalis, and the medial and cortical nuclei of the amygdala. Labelled cells, in small numbers, were also detected in the mesencephalic central gray (CG), lateral hypothalamus, subiculum and entorhinal cortex. The neuro-anatomical pattern of estrogen-concentrating cells in the hamster supports the concept of a generalized vertebrate pattern. Furthermore, a comparison of hamster and rat patterns of cellular ³H-estradiol (³H-E₂) concentration appears to suggest that species differences in their responsiveness to estrogen may be paralleled by differences in estrogen binding.

Attack priming in female Syrian golden hamsters is associated with a c-fos-coupled process within the corticomedial amygdala

“…56), suggesting the possibility that downstream genomic effects of c-fos expression in the CMA might contribute to the prolonged time-course of attack priming. We also note the temporal coincidence in the report of Payne et al 43 that hypothalamic serotonin concentration in hamsters reaches a nadir 30 min after a fight.…”

“…Further evidence for internal mediation has been developed by interpolating different delay intervals between the priming and probe trials. These studies show that attack latencies remain reduced for at least 30 min after priming. 44 ,46,52 Finally, we note that the priming effect is not restricted to attacks on drug-treated intruders; priming two subjects before they are placed in the same arena hastens the onset of fighting between them.…”

“…Several lines of evidence have implicated these subregions of the CMA in the control of sexual behavior; for example, these are the regions containing the highest density of sex steroid-concentrating neurons. 30 Our observations on the CMA's involvement in aggression have, in contrast, focused on the rostral and ventral aspects of the CMA. This contrast was highlighted by a preliminary study carried out in our laboratory using four pairs of animals selected from our population of aggressive, ovariectomized females.…”

Evidence that oestrogen exerts an equivalent negative feedback action on LH secretion in male and female ferrets

“…Autoradiographic studies show that the distribution of oestrogen receptors in the brains of reflex ovulating species such as the ferret (Baum et al, 1986), mink (Morrell et al, 1977), cat (Rees & Michael, 1984) and rabbit (Anderson, 1975) resembles that of several spontaneously ovulating species, including the rat (Pfaff & Keiner, 1973), hamster (Krieger et al, 1976), guineapig (Sar & Stumpf, 1975) and monkey (Pfaff et ai, 1976). The distribution of GnRH neurones in the ferret (King & Anthony, 1984;Sisk et al, 1988), with numerous immunopositive cell bodies located in the mediobasal hypothalamus and pituitary stalk, more closely resembles that of the human (Barry, 1976) and monkey (Barry & Carette, 1975) than that of the rat (King et ai, 1982), in which most GnRH cell bodies are located more rostrally in the hypothalamus and preoptic area.…”

Cybernetic principles in the systematic concept of hypothalamic feeding control

“…Because many hypothalamic neurons possess a high number of binding sites for estrogens, the modulation of feeding behavior by a direct mechanism on hypothalamic neurons can be suggested (29). This was emphasized by the discovery that estrogens decrease melanin-concentrating hormone (MCH) expression in orexigenic neurons of the LHA (30, 31).…”