THE PITUITARY BODY 



condenser-discharge method failed to cause ovulation but 

 did bring about maturation of ova. They believed that the 

 cervical sympathetics have only a limited control over the dis- 

 charge of gonadotropic hormones by the anterior pituitary. 

 Brooks (1937) was unable to prevent the ovulation following 

 coitus in the rabbit by removing sense organs or parts of the 

 central and peripheral nervous systems (such as the olfactory 

 bulbs or the cerebral cortex or the sacral cord, the abdominal 

 sympathetics, the uterus, and part of the vagina). 



Diffuse powerful electrical stimulation applied to the brain 

 or lumbosacral cord of the rabbit can cause ovulation, al- 

 though the latter occurs 7-14 hours later than after coitus 

 (Marshall and Verney, 1936). Harris (1936) applied a similar 

 stimulus to the head of the adult female rat; as a result pseu- 

 dopregnancy occurred in about 70 per cent of the animals. 

 The same author (1937) was able to produce ovulation, some- 

 times associated with the formation of cystic or hemorrhagic 

 folHcles, by applying an electrical stimulus to the hypothala- 

 mus or pituitary of the rabbit. According to Haterius and 

 Derbyshire (1937), who used a small bipolar electrode, a 

 sharply localized area 5 mm. below the surface above and an- 

 terior to the optic chiasm causes ovulation when stimulated. 

 There is an associated motor response (flexion of hind legs, 

 pelvis, and trunk; elevation of tail). The authors used rab- 

 bits. Cahane and Cahane (1935-36) described histologic 

 changes in the anterior pituitary and genital atrophy in 2 

 of 8 rats surviving a lesion made in the infundibulo-tuberal 

 region of the hypothalamus. 



Presumably impulses from the hypothalamus (or thala- 

 mus) pass down the stalk and provoke secretion of gonado- 

 tropic hormones when central stimulation is followed by ovu- 

 lation and pseudopregnancy. However, the evidence is much 

 less complete than that afforded by similar studies of the se- 

 cretion of the diuresis-inhibiting hormone of the pars neuralis. 

 Harris (1937) stated that lesions of the stalk were followed by 

 genital atrophy in both male and female rabbits. According 



f 100 1 



