title: Carbachol triggering of desynchronized sleep phenomena: enhancement via small volume infusions.
abstract: Two physical factors affecting the behavioral effects of drugs microinjected into the pontine tegmentum have been studied. Reducing the volume of vehicle produced a dramatic enhancement of the capacity of the long-acting cholinergic agent carbachol to induce desynchronized (D) sleep-like behavior (Dcarb). Enhancement of Dcarb was also achieved by substitute passive diffusion for active pumping of a given volume of carbachol solution. Controlling these two physical factors makes Dcarb a compelling experimental model for the study of D sleep mechanisms. The results also give support to the concept of a localized population of cholinoceptive neurons in the pontine reticular formation whose activation is a key step in the generation of physiological D.
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D002415:Cats; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D004576:Electromyography; D005071:Evoked Potentials / Q000187:drug effects; D011149:Pons / Q000187:drug effects*; D011950:Receptors, Cholinergic / Q000187:drug effects; D012154:Reticular Formation / Q000187:drug effects; D012894:Sleep Stages / Q000187:drug effects*; D012895:Sleep, REM / Q000187:drug effects
chemical_list: D011950:Receptors, Cholinergic; D002217:Carbachol