Cerebral ventricular infusion of excess calcium in the rat: effects on sleep states, behavior and cortical EEG.
Sleep and behavior of the rat were recorded during cerebroventricular infusion of artificial cerebrospinal fluid (aCSF) containing regular or excess concentrations of calcium. Three different types of aCSF were used for control infusions. Depending on the ionic composition, paradoxical sleep (PS) was reduced by 6--52% during a 1-h aCSF infusion period, whereas the total amount of sleep was not altered. The depression of PS by aCSF could be prevented by increasing the concentration of Ca in the infusate by a factor of 2--5 (2.6--9.1 mM). Infusions of high concentrations of Ca (9.1--54.6 mM) caused feeding and wet-dog shakes. A slow-wave cortical EEG pattern prevailed during feeding elicited by either infusion of excess Ca or systemic administration of a small dose of pentobarbital. It is concluded (a) that the ionic composition of the CSF may selectively influence the occurrence of a sleep state, and (b) that Ca-induced feeding may be related to a covert sedative action of this cation.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002118:Calcium / Q000008:administration & dosage / Q000134:cerebrospinal fluid / Q000494:pharmacology*; D004569:Electroencephalography; D004576:Electromyography; D007276:Injections, Intraventricular; D008297:Male; D051381:Rats; D012890:Sleep / Q000187:drug effects*; D012895:Sleep, REM / Q000187:drug effects; D013997:Time Factors
D002118:Calcium