Are there cholinergic and non-cholinergic paradoxical sleep-on neurones in the pons?
Using microiontophoresis on unanesthetized head-restrained cats, we have found two distinct groups of neurones exhibiting tonic discharge specific to paradoxical sleep (PS) (PS-on neurones) in the mesopontine tegmentum, which contains both cholinergic and non-cholinergic neurones. One group is characterized by a broad action potential, slow conduction velocity and an inhibitory response to a potent cholinergic agonist, carbachol, applied iontophoretically during PS. The other is characterized by a short action potential, fast conduction velocity and an excitatory response to applied carbachol. All PS-on neurones were excited by glutamate. The present findings demonstrate the existence of two types of PS-on neurones and suggest their cholinergic and noncholinergic neurochemical properties.
Sakai
K
K
INSERM U52, Département de Médecine Expérimentale, Université Claude Bernard, Lyon, France.
Koyama
Y
Y
D000818:Animals; D002415:Cats; D002799:Cholinergic Fibers / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D011149:Pons / Q000502:physiology*; D012890:Sleep / Q000502:physiology*