Neurotrophic effects of steroids on lesion-induced growth in the hippocampus. I. The asteroidal condition.
Young adult male and female Sprague-Dawley rats were randomly assigned to be gonadectomized (GDX), adrenalectomized (ADX), gonadectomized and adrenalectomized (GDX/ADX) or left intact. One week following initial surgery all animals were subjected to a lesion of the entorhinal cortex (ERC) which partially denervates the ipsilateral hippocampal dentate gyrus. Fifteen days after the ERC ablation, the brains were analyzed for changes in reactive outgrowth of the hippocampal commissural-associational (C-A) afferents. Under intact conditions there were no differences between male and female subjects. Female subjects demonstrated a suppression of sprouting following GDX alone and an enhancement of growth following ADX alone. Reactive growth in male subjects was unaffected by GDX or ADX alone. When placed in the 'asteroidal' (GDX/ADX) condition, reactive outgrowth of male subjects is significantly impaired as compared to female subjects. The results suggest a complex inter-relationship between the gonadal and adrenal hormones and a possible neurotrophic effect for the gonadal steroids.
Scheff
S W
SW
Department of Anatomy and Neurobiology, Sanders-Brown Research Center on Aging, University of Kentucky, Lexington 40536.
Morse
J K
JK
DeKosky
S T
ST
D000315:Adrenalectomy; D000818:Animals; D001369:Axons / Q000502:physiology*; D001930:Brain Injuries / Q000503:physiopathology*; D005260:Female; D006624:Hippocampus / Q000254:growth & development*; D008297:Male; D000090204:Mesothelin; D009473:Neuronal Plasticity; D009919:Orchiectomy; D010052:Ovariectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012727:Sex Characteristics