Estrogen stimulates neuronal plasticity in the deafferented hypothalamic arcuate nucleus in aged female rats.
The hypothalamic arcuate nucleus (ARCN) was examined ultrastructurally 3 weeks after the complete deafferentation of the medial basal hypothalamus (MBH) with the island isolation technique in ovariectomized aged female rats (720-930 days of age). The mean numbers of axodendritic and axosomatic synapses in the ARCN decreased to about one-third of those in the intact controls. However, the treatment with estradiol benzoate (2 micrograms/day) during the 3 weeks following the day of brain surgery brought about a marked increase in the numbers of these synapses. The data suggest that the ARCN neurons of aged female rats still retain plasticity to react to deafferentation under influences of estrogen.
D000344:Afferent Pathways / Q000502:physiology; D000375:Aging / Q000187:drug effects*; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000502:physiology* / Q000648:ultrastructure; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D008854:Microscopy, Electron; D009409:Nerve Crush; D009473:Neuronal Plasticity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000187:drug effects; D013997:Time Factors
D004958:Estradiol