Hippocampal dentate granule cell degeneration after adrenalectomy in the rat is not reversed by dexamethasone.
Although adrenalectomy has been reported to induce a selective and sometimes nearly complete degeneration of hippocampal dentate granule cells, Azmitia and colleagues recently reported (Mol. Brain Res., 19 (1993) 328-332) that normal hippocampal structure can nonetheless be restored within a matter of days by dexamethasone in the drinking water. We have attempted to confirm this remarkable finding. Four months after adrenalectomy, rats were given vehicle or dexamethasone for 5 days and then sacrificed. Histological analysis revealed that vehicle-treated adrenalectomized rats exhibited a full spectrum of granule cell loss, which spanned mild to nearly complete cell loss. Dexamethasone-treated adrenalectomized rats did not differ from vehicle-treated adrenalectomized rats and, in fact, exhibited a virtually identical spectrum of granule cell loss. These results confirm that adrenalectomy reliably induces hippocampal granule cell degeneration in a majority of animals and indicate that dexamethasone does not restore normal hippocampal structure once granule cell loss has occurred.
Sloviter
R S
RS
Neurology Research Center, Helen Hayes Hospital, New York State Department of Health, West Haverstraw 10993, USA.
Sollas
A L
AL
Neubort
S
S
D000315:Adrenalectomy; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D018891:Dentate Gyrus / Q000166:cytology* / Q000187:drug effects; D003907:Dexamethasone / Q000494:pharmacology*; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology*; D009410:Nerve Degeneration / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D005938:Glucocorticoids; D003907:Dexamethasone