Synaptology of luteinizing hormone-releasing hormone neurons in the preoptic area of the male rat: effects of gonadectomy.
Ultrastructural analysis of the synaptic input to luteinizing hormone-releasing hormone neurons has previously shown that in male rats these cells acquire an increased density of innervation with increasing age [Witkin J. W. (1987) Neuroscience 22, 1003-1013]. To determine if this aging phenomenon might be due to changes in the steroid environment, we examined luteinizing hormone-releasing hormone neurons, using methods identical to the earlier study, in sham operated and 1 day and 4 week castrated male rats. The density of synaptic input to luteinizing hormone-releasing hormone neurons did not vary among the three experimental groups. Furthermore, there were no differences in the relative numbers of various morphological categories of synaptic boutons (characterized by vesicle type: clear vs dense and round vs pleomorphic) among the groups. Long term castration did result in a slight decrease in immunocytochemically detectable luteinizing hormone-releasing hormone neuron numbers. These results suggest that gonadal steroid deprivation does not alter the total density or morphological characteristics of synaptic input to the luteinizing hormone-releasing hormone neuron in the male rat.
Witkin
J W
JW
Department of Anatomy and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032.
D000818:Animals; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008854:Microscopy, Electron; D009919:Orchiectomy; D011301:Preoptic Area / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D051381:Rats; D011916:Rats, Inbred F344; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D013739:Testosterone / Q000502:physiology*
D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone