K. LISSAK AND E. ENDROCZI 



299 



in experiments with depth electrodes that stimulation of mesencephalic 

 reticular formation, posterior hypothalamus including the mamillary 

 bodies and the intralaminar nuclei of the thalamus activates the pituitary- 

 adrenocortical system. This can be checked directly by estimating the 

 corticoid content of the blood in the adrenal vein. 



li S 12 i6 20 Ih 2S iZ 36 W 'i'<Cm 



^ 



n: 



Cpdf- CpdaCpji fioH- 



' ' nroaestet^one 



pro(jt 



Fig. 



Effect of stimulation ot ainygdale and pyritorni cortex on dogs. The 

 figure shows appearance of 17-hydroxy-progesteronc following 

 repeated stimulation (15 minutes daily for 5-6 days) of medial part 

 of amygdale-pyriform cortex. Stimulation of lateral areas elicited 

 only marked ele^'ation of resting corticoid secretion without the 

 appearance of new secretory product or sexual hyperactivity. 



Step-like changes in the behaviour of animals were observed tiuring the 

 stimulation of the above-mentioned structures as a consequence of rising 

 intensity of stimuli. Marked orientation cliciteci by threshold stimuli was 

 followed by emotional reactions (fear, avoiciing-reaction), and further 

 elevation of stimulus mtensity induced extreme furious behaviour 

 (O, 5-5, O V, 60-90 H, 3 msec). After cessation of stimulation the original 

 behaviour returned without delay. 



