title: Serotonin and norepinephrine uptake in discrete brain regions during the pregnant mare serum (PMS) induced estrous cycle in the rat.
abstract: The role of hypothalamic and limbic aminergic systems in neuroendocrine control in the rat has been investigated by measuring the temporal changes in serotonergic and noradrenergic neuronal uptake in a model of the estrous cycle. Using the pregnant mare serum (PMS) model of induced ovulation and an in vitro uptake system, serotonergic activity reached peak values (p = 0.01) in the suprachiasmatic nuclear region (SNR) and median eminence (ME) (p = 0.007) during the critical period for luteinizing hormone release. 5, 7-dihydroxytryptamine lesions of the SNR or ME regions inhibited PMS induced ovulation suggesting that at least in these two areas a certain amplitude of 5-HT activity may be required at some time prior to the critical period for LH release. Serotonergic uptake during diestrus in the median eminence showed maximum values during the mid-light phase suggesting a role for this region in ovulation control mechanisms prior to the proestrous critical period. Significant changes (p = 0.001) in serotonergic uptake were found in mid to later light diestrus in the amygdala. This pattern was repeated during proestrus and estrus only in the amygdala suggesting a daily pattern of serotonergic uptake during the estrous cycle. Significant changes (p = 0.001) in noradrenergic uptake only occurred in the amygdala during proestrus.
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D004971:Estrus / Q000187:drug effects*; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism*; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D006064:Gonadotropins, Equine; D012701:Serotonin; D009638:Norepinephrine