Extracellular potentials were recorded from medial preoptic-septal (MPOA-S) neurons in 2-week and 3-4 month ovariectomized rats, and the effects of microelectrophoresed 17β-estradiol hemisuccinate (17βE2S), acetylcholine (Ach), cortisol hemisuccinate (CS) and glutamate (Glut) were studied, 17βE2S failed to produce changes in the firing rate of the majority of MPOA-S neurons tested, but Ach excited 48% of these neurons. MPOA-S neurons showed very little response to either Glut or CS. Previous findings from this laboratory have demonstrated that MPOA-S neurons recorded in 4-day cyclic female rats will respond to 17βE2S. Therefore the present results suggest that the ovarian steroids are necessary for maintaining this electrical sensitivity. Also, the involvement of a specific membrane or cytoplasmic receptor is discussed.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Endocrine and Autonomic Systems
- Cellular and Molecular Neuroscience