Seizure induced C-Fos mRNA in the rat brain: comparison between young and aging animals.
The molecular mechanisms associated with age-related alterations in the pharmacological and physiological properties of hippocampal and cortical neurons in response to chemically induced seizure are largely unknown. Administration of pentylenetetrazole (PTZ) (50 mg/kg body weight) to rats of various ages evoked tonic-colonic seizures. Using RNA gel blot analysis we found that 1 h after the onset of seizure, the mRNA for the protooncogene c-fos was increased in the hippocampus and cortex of 3-month-old rats. The levels of c-fos mRNA in the hippocampus and cortex of 3-month-old rats returned to control levels by 3 h after PTZ administration. The levels of c-fos mRNA in the hippocampus and cortex of 20-month-old and 30-month-old rats peaked at 3 h and returned to basal levels by 15 h following PTZ treatment. These results suggest that the induction of immediate-early gene expression, as exemplified by c-fos, is not impaired in the aged rat brain. However, the aged rat brain responded more slowly to chemically induced seizure and the levels of c-fos mRNA induction are decreased by about 49% in the cortex and by 27% in the hippocampus of 30-month-old rats, as compared to the levels expressed by 3-month-old rats.
Retchkiman
I
I
Institute of Gerontology, University of Erlangen-Nürnberg, Germany.
Fischer
B
B
Platt
D
D
Wagner
A P
AP
D000375:Aging; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012640:Seizures / Q000378:metabolism*; D013997:Time Factors
D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger