摘要:

AbstractCopulatory output of the mature male rat was measured over an eight week period under conditions of each male having free access to a constant stimulus female.Of 71 males tested 31 of these (44%) had to be discarded as they did not reach our arbitrary minimum criterion of producing copulation plugs on 4 out of 14 nights during the initial (control) observation period. An extreme individual variability in sex drive was noted among the animals used for further testing.Employing equal sized groups of about ten animals and using a two week interval as the basic unit of time; the mean sexual activity for the group measured as number of copulation plugs found and mean percentage of nights on which copulation occurred indicated an extreme similarity of all groups. Maximum sexual response occurred during the initial 14 day test period and both measures of activity used (copulation plugs and days on which copulation occurred) declined by approximately 50% over the eight week test period.A similar 50% decline in response occurred following lesions in the middle hypothalamus dorsal to the arcuate nucleus or lesions dorsal to the hypothalamus involving the habenula and surrounding cortex. It was concluded these areas are not involved in regulation of copulatory behavior in the male rat.Lesions in the mammillary region (mostly medial) resulted in 50% of the animals showing a sustained constant copulatory output during the eight week test, while the remaining 50% (mostly with lateral lesions) showed marked increases which expressed as the mean of the group amounted to 90% copulation plugs and 50% in nights on which copulation occurred.Thus it was concluded that structures in the mammillary region at the junction of the diencephalon and mesencephalon normally exert a regulatory (inhibitory) influence on the sex drive in the male rat.

ISSN:0022-104X    

DOI:10.1002/jez.1401610112

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

摘要:

AbstractThe caudal neurosecretory system of the teleostTilapia mossambicawas subjectedin vivoandin vitroto intense and prolonged electrical stimulation. Repeated firing of neurosecretory units was observed in thein vivopreparations, and compound action potentials were recordedin vitro.Evidence of depletion of neurosecretory material from the urophysis was obtained on the light and electron microscope levels. Ultrastructurally two pictures were encountered in the responding axon terminals: (1) a decrease in electron density of most of the elementary neurosecretory granules in individual terminals; (2) complete or nearly complete disappearance of granules and vesicles from individual terminals. The latter picture is considered to be a more advanced stage of depletion.

ISSN:0022-104X    

DOI:10.1002/jez.1401610113

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY

ISSN:0022-104X    

DOI:10.1002/jez.1401610101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1966

数据来源: WILEY