title: Daily rhythms of seizure activity and behavior in a model of atypical absence epilepsy.
abstract: We studied daily rhythms of chronic seizure activity and behavior in adult rats and mice treated with the cholesterol biosynthesis inhibitor AY-9944 (AY) during early postnatal development. Chronic atypical absence seizures were verified in the AY-treated animals by the presence of spontaneous 5- to 6-Hz slow spike-wave discharges (SSWDs) in the neocortex. General behavioral activity, as measured by total movements (TM), movement time (MT), ambulatory movement time (AMT), time spent in center of arena (CT), jumps (JFP), and rotational behavior (TURNS), were continuously recorded under a 12-hour light:12-hour dark photocycle. The average SSWD duration in AY-treated rats varied daily, with two peaks occurring at approximately dark phase and light phase onset. Mice treated with AY exhibited significant increases in all behavioral measures during the light and dark phases, with the exception of light-phase CT, which did not differ from that of controls. Consequently, the daily rhythm of total behavioral activity (TM) exhibited a significantly higher mean oscillation (mesor) and amplitude without evidence of phase shift compared with the TM rhythm of controls. The occurrence of SSWD activity in the AY model appears to be subject to regulation by biological timing mechanisms and, furthermore, associated with motor hyperactivity that does not alter the timing of behavioral rhythmicity.
authors.affiliation: Brain and Behavior Research Program, The Hospital for Sick Children, Toronto, Ont., Canada.
authors.forename: Lee S
authors.initials: LS
authors.lastname: Stewart
authors.forename: Eduard
authors.initials: E
authors.lastname: Bercovici
authors.forename: Ruchica
authors.initials: R
authors.lastname: Shukla
authors.forename: Irina
authors.initials: I
authors.lastname: Serbanescu
authors.forename: Vasan
authors.initials: V
authors.lastname: Persad
authors.forename: Niraj
authors.initials: N
authors.lastname: Mistry
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cortez
authors.forename: O Carter
authors.initials: OC
authors.lastname: Snead
mesh_terms: D000818:Animals; D000924:Anticholesteremic Agents; D001522:Behavior, Animal; D002540:Cerebral Cortex / Q000503:physiopathology; D002940:Circadian Rhythm; D004195:Disease Models, Animal; D004569:Electroencephalography; D004832:Epilepsy, Absence / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009068:Movement; D051381:Rats; D020318:Rats, Long-Evans; D012640:Seizures / Q000139:chemically induced / Q000503:physiopathology*; D001371:trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride
chemical_list: D000924:Anticholesteremic Agents; D001371:trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride