scholarly journals Electrical Stimulation of the Amygdala Modifies the Negative Feedback Effect of Glucocorticoids on the Adrenocortical Responses to Stress

2015 ◽  
Vol 22 (6) ◽  
pp. 394-399 ◽  
Author(s):  
Joseph Weidenfeld ◽  
Anna Itzik ◽  
Haim Ovadia
Keyword(s):  
Electrical Stimulation ◽  
Negative Feedback ◽  
Feedback Effect ◽  
Adrenocortical Responses ◽  
Stimulation Of

THE EFFECT OF OVARIAN STEROIDS ON HYPOTHALAMIC THRESHOLDS FOR OVULATION IN THE FEMALE RAT

1971 ◽  
Vol 49 (3) ◽  
pp. 421-429 ◽  
Author(s):  
P. G. McDONALD ◽  
D. P. GILMORE
Keyword(s):  
Negative Feedback ◽  
Median Eminence ◽  
Preoptic Area ◽  
Feedback Effect ◽  
Female Rats ◽  
Female Rat ◽  
Ovarian Hormone ◽  
Ovarian Steroids ◽  
Positive Feedback Effect ◽  
Stimulation Of

SUMMARY Electrochemical stimulation of the basal and preoptic hypothalamus, under sodium pentobarbitone anaesthesia, was carried out on the day of pro-oestrus in normal cycling and in ovarian hormone-treated female rats. Control rats ovulated in response to 25, 50 and 100 μA for 60 s in the median eminence and to 10 μA for 60 s in the preoptic area. Oestradiol (1 μg) given 24 h before median eminence stimulation significantly increased the number of rats ovulating. An injection of progesterone (1 mg) 24 h before median eminence stimulation did not affect the number of animals ovulating or the number of ova shed. In contrast, there was a significant reduction in the number of animals ovulating after preoptic stimulation. Stimulation of the median eminence 2–4 h after progesterone administration increased the number of animals ovulating. The results suggest that both oestradiol and progesterone exert a positive feedback effect at or below the level of the median eminence and that the negative feedback effect of progesterone is exerted on the preoptic area.

Sign in / Sign up

Export Citation Format

Share Document