CHANGES IN THE FIRING RATE OF SINGLE PREOPTIC-SEPTAL NEURONS INDUCED BY DIRECT APPLICATION OF NATURAL AND CONJUGATED STEROIDS
1981; Elsevier BV; Linguagem: Inglês
10.1016/b978-0-08-026864-4.50021-9
Autores Tópico(s)Olfactory and Sensory Function Studies
ResumoABSTRACT Extracellular single unit activity was recorded in the medial septal-preoptic area of 21 Urethane anaesthetized female guineapigs. Pressure application of β-Estradiol (E2) and microiontophoresis of E2−7α – butyric acid (E2b) were made concomitantly through the same multibarrelled microelectrode. 1) Pressure ejection of picoliter volumes of E2 into their immediate environment promptly increased firing rates in 13,49% of the 215 neurons recorded. 3,72% showed an inhibitory response. The latencies of the responses varied within 30 s. This suggests a possible membrane action of E2. 2) Microiontophoresis of E2b caused instantaneous changes in firing rates but these responses were not correlated with those obtained with E2. It is apparent that the E2 derivative does not mimic the action of the natural hormone. 3) Some cells were successfully tested with E2 and Cortisol, both applied by pressure. The advantages of pressure ejection over other modes of application for demonstrating E2 effects on nerve cells in vivo are discussed.
Referência(s)