Differential enhancement of rapid eye movement sleep signs in the cat: a comparison of microinjection of the cholinergic agonist carbachol and the β-adrenergic antagonist propranolol on pontogeniculo-occipital wave clusters

The cholinergic agonist carbachol and the β-adrenergic antagonist propranolol were microinjected at the same pontine sites and their effects on polygraphic rapid eye movement (REM) sleep, especially pontogeniculo-occipital (PGO) waves, were measured. While both propranolol and carbachol enhanced PGO wave activity and polygraphic REM sleep, the carbachol-correlated enhancement was more impressive. The increases in REM sleep signs elicited by carbachol were 5-fold over baseline and lasted throughout the 4-h recording period. Propranolol elicited 2.5-fold increases that were significant in the first 2 h only. Yet, the increase in PGO wave activity evoked by propranolol was equal to that of carbachol during non-REM sleep and wakefulness. The results indicate that while propranolol is less potent in activating the distributed neuronal network responsible for REM sleep generation, it selectively facilitates that part of the network responsible for PGO waves.