Inhibitory effect of state independent ponto-geniculo-occipital waves on seizure occurrence induced by local application of penicillin into the temporal lobe amygdala.
OBJECTIVE
In order to explore the possible inhibitory role of the phasic phenomena of REM sleep ponto-geniculo-occipital (PGO) waves over epilepsy, seizure activity produced by topic administration of Na-penicillin (PCN) has been analyzed during sustained PGO waves irrespective of current state. PGO waves were induced by the injection of carbachol in the peribrachial area.


METHODS
The development of acute experimental epilepsy was compared among nine chronically implanted, adult, male cats, by means of polygraphic 23 h recordings. Our protocol consisted of sets of 4 trials: carbachol; PCN; carbachol followed by PCN and finally PCN followed by carbachol. Each cat received one single set and all trials were carried out with a seven days interval, in order to compare the epileptic activity both in the presence of PGOs and without them.


RESULTS
PGO waves 1) exert an inhibitory influence over number and duration of the Generalized Convulsive Seizures (GCSs) and 2) spike frequency; 3) increase the latency of GCSs; and 4) restores sleep alterations produced by experimental epilepsy.


CONCLUSIONS
PGO waves exhibit an inhibitory influence over seizures induced by PCN. These data support the hypothesis that this phasic phenomenon of REM sleep have a depressant effect on epilepsy, inhibit seizures and normalize sleep architecture changes induced by seizures. We suggest that one possible function of PGO activity is to protect the brain from intense changes in neuronal excitability; namely convulsive activity.
Salado
Ignacio Ramírez
IR
Departamento de Cronobiología, División de Investigaciones en Neurociencias, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calz. México-Xochimilco 101, Col. Sn Lorenzo Huipulco, 14370, México, D.F. Mexico. salado@imp.edu.mx
García
Ana Paula Rivera
AP
Aguilar
Manuel Alejandro Cruz
MA
Calvo
José María
JM
D000679:Amygdala / Q000187:drug effects / Q000502:physiology*; D018712:Analgesics, Non-Narcotic / Q000494:pharmacology; D000818:Animals; D001931:Brain Mapping; D002217:Carbachol / Q000494:pharmacology; D002415:Cats; D004195:Disease Models, Animal; D004569:Electroencephalography / Q000379:methods; D005829:Geniculate Bodies / Q000503:physiopathology*; D008297:Male; D008845:Microinjections; D009434:Neural Pathways / Q000187:drug effects / Q000502:physiology; D009778:Occipital Lobe / Q000503:physiopathology*; D010400:Penicillin G; D011149:Pons / Q000503:physiopathology*; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D012640:Seizures / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D012890:Sleep / Q000187:drug effects / Q000502:physiology; D013702:Temporal Lobe / Q000187:drug effects / Q000502:physiology*; D014851:Wakefulness / Q000187:drug effects / Q000502:physiology
D018712:Analgesics, Non-Narcotic; D002217:Carbachol; D010400:Penicillin G