MALE-FEMALE DIFFERENCE IN SYNAPTIC ORGANIZATION OF THE SEXUALLY DIMORPHIC NUCLEUS OF THE PREOPTIC AREA IN THE RATS / 解剖学报

ABSTRACT

The synaptic organization of the sexually dimorphic nucleus of the preopticarea(SDN-POA)of male and female rats were examined with electron micro-scope.The results indicated that the synaptic pattern of SDN-POA showedsignificant sexual dimorphism1.The numbers of total and shaft synapses whichoccupied the vast majority of total synapse were 2 times greater in male than infemale.2.The number of spine synapse of the female was 4.6 times greater thanthat of the male.3.In female,either the numbers of spine synapse with clear andmixed synaptic vesicles or the numbers of symmetrical and asymmetrical spinesynapses were markedly higher than in male.In contrast,the ratio of Gray Ⅱ toGray Ⅰ was 2.4 times larger in male than in female.4.The number of shaft synapsewith clear vesicle was greater in male than in female.In both sexes,however,thesignificant difference in the number of shaft synapse with mixed vesicle was notfound.5.There was no significant sexual difference in the number of asymmetricalshaft synapse,while the number of symmetrical shaft synapse was 2.7 times greaterin male than in female.