Jm. Calvo et R. Fernandezmas, TRANSITORY AND SHORT-DURATION CHANGES OF SLEEP ORGANIZATION PROVOKED BY AMYGDALOID KINDLING IN THE CAT - A DAILY 23-HOUR SLEEP RECORDING STUDY, Epilepsy research, 19(1), 1994, pp. 1-13
The effect of amygdaloid kindling on sleep organization was tested in
chronically implanted cats on a 12:12 light-dark cycle. Electrical kin
dling stimuli were delivered to the amygdala every 2 h during the ligh
t period. Total sleep time and percentage, mean duration, and mean num
ber, as well as the hourly accumulation of waking (W) and sleep (slow
wave sleep I and II, and paradoxical sleep) episodes were assessed fro
m daily 23-h sleep recordings, consisting of baseline control recordin
gs, control recordings where cats were briefly alerted at 2-h interval
s to mimic the kindling trials manipulation, and recordings on each ki
ndling day. The kindling process was completed within six days achievi
ng three to five consecutive fully kindled seizures. Analysis of total
recording time showed that the kindling process enhanced W stage and
diminished total sleep time only on the second kindling day. Analysis
of light and dark periods demonstrated compensatory W and sleep change
s during the dark periods. Hourly sleep stage time accumulation was sl
owed during kindling trials, but compensated while stimuli were suspen
ded. All of these changes returned to baseline values at the end of ki
ndling. No significant differences between changes induced by kindling
and those produced by alerting trials were found. We conclude that sl
eep alterations can not be exclusively attributed to kindling developm
ent, and that sleep is able to become adapted to the focal and general
ized seizures effect.