GABAA receptor activation augments electrically-stimulated release of norepinephrine (NE) from rat brain slices. Because this effect is not observed in synaptoneurosomes, GABA probably acts on inhibitory interneurons to disinhibit NE release. To determine whether opioids or adenosine influence GABA-augmented NE release, hypothalamic and cortical slices from female rats were superfused with GABA or vehicle in the presence and absence of 10 microM morphine or 100 microM adenosine.
View Article and Find Full Text PDFCopulation in male hamsters is stimulated by exposure to vaginal secretions of conspecifics. These pheromones also stimulate fos expression in neural areas that regulate copulation including: the medial nucleus of the amygdala, the bed nucleus of the stria terminalis, and the preoptic area. The pheromones in vaginal secretions are detected by both the main and accessory olfactory systems.
View Article and Find Full Text PDFThis review focuses on findings from our laboratory regarding mechanisms by which the ovarian steroid hormones, estradiol (E2) and progesterone (P), act in the hypothalamus (HYP) to regulate the expression of lordosis, an important component of female reproductive behavior in rats and many other species. The first section summarizes recent work suggesting that cGMP, perhaps via P-receptor activation, may be an intracellular mediator of the facilitatory actions of a variety of hormones and neurotransmitters on lordosis behavior in E2-primed rats. In the second section, we focus on E2 and P regulation of norepinephrine (NE) neurotransmission in the HYP.
View Article and Find Full Text PDFActivation of alpha1-adrenergic receptors has been linked to the control of blood pressure, neuroendocrine secretion, reproductive behavior and mood. The present study describes the distribution of alpha1B-adrenergic receptor immunoreactivity in female rat brain regions involved in stress and neuroendocrine function. The pattern of immunolabeling seen resembles that obtained in previous in situ hybridization studies.
View Article and Find Full Text PDFGABAA receptor activation augments stimulated release of 3H-norepinephrine (NE) in brain slices from female rats. This effect is not blocked by acetazolamide or MK-801, indicating that permeability of the GABAA chloride channel to bicarbonate ions and NMDA receptor activation do not mediate GABA-induced NE release. Furthermore, GABA augments 3H-NE release from slices, but not from isolated nerve terminals (synaptosomes), indicating that interneurons mediate GABA effects on 3H-NE release.
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