Infusion of 3alpha,5alpha-THP to the pontine reticular formation attenuates PTZ-induced seizures.
Whether progesterone (P(4)) and its metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP) have anti-seizure effects through actions in the pontine reticular formation (PRF) was investigated. Concentrations of P(4) and 3alpha, 5alpha-THP in the PRF were greater in proestrous and hormone-primed rats, that are typically more resistant to seizure-induction, than diestrous and males rats. Ovx, Long-Evans rats with unilateral microinjections into the PRF of 3alpha,5alpha-THP (5 microg/0.2 microl), but not P(4) (11 microg/0.2 microl) or vehicle (beta-cyclodextrin), had a greater latency and lower incidence of tonic-clonic seizures induced by pentylenetetrazol (PTZ; 70 mg/kg, IP) administration. Infusions that missed the PRF were not effective. These data suggest 3alpha,5alpha-THP has anti-seizure effects in part through actions in the PRF.
Frye
C A
CA
Department of Psychology, Biological Sciences & The Neurobiology Research Center, The University at Albany-SUNY, 1400 Washington Avenue, Albany, NY 12222, USA. cafrye@cnsunix.albany.edu
Manjarrez
J
J
Camacho-Arroyo
I
I
D000818:Animals; D003292:Convulsants; D004031:Diestrus / Q000187:drug effects / Q000502:physiology*; D005260:Female; D008297:Male; D010052:Ovariectomy; D010433:Pentylenetetrazole; D011280:Pregnanolone / Q000031:analogs & derivatives* / Q000627:therapeutic use; D011359:Proestrus / Q000187:drug effects / Q000502:physiology*; D011374:Progesterone / Q000031:analogs & derivatives / Q000378:metabolism / Q000627:therapeutic use*; D051381:Rats; D020318:Rats, Long-Evans; D012154:Reticular Formation / Q000187:drug effects / Q000502:physiology*; D012640:Seizures / Q000139:chemically induced / Q000188:drug therapy*
D003292:Convulsants; D011374:Progesterone; C028952:allopregnan-20 alpha-ol-3-one; D011280:Pregnanolone; D010433:Pentylenetetrazole