Figure 10 : Differential effects of lesions of the lower brain stem
on the two states of sleep
Lesions projected onto a sagittal section of the brain stem. Diagonal
hatching: coagulation of the median three-quarters of the nucleus reticularis
pontis oralis and interpeduncular nucleus. Persistence of P.S. (15%).
lncrease in slow activity to 90% during first week. Return to normal proportion
of slow sleep (60%) after third week (mean of 3 cats). Black area: lesion
causing complete suppression of P.S. for 15-97 days. Mean proportion of
slow sleep in 4 animals: 40%. Dotted area: Lesion in the caudal part of
the nucleus reticularis pontis caudalis and the anterior part of the nucleus
giganto-cellularis (involving the median two-thirds of these nuclei).
Suppression of P.S. for 3 days followed by reappearance with normal rhythm
(18%). Mean proportion of slow sleep in 2 cats: 40%. The proportion of
slow sleep was determined in all animals in an average of 6 h of recording