Saline preference and body fluid analyses in rats after intrahypothalamic injections of carbachol

摘要: Abstract Two experiments in rats supported previous suggestions that drinking induced by intrahypothalamic injections of carbachol directly activates a thirst motivational system. In Experiment 1 the palatability and osmotic properties fluids were varied presenting different concentrations NaCl solution one-and two-bottle tests. Drinking was found to be closely related concentration fluid, being augmented when palatable dilute saline available but decreasing unpalatable concentrated solutions presented instead. Fluid intakes similar this regard well-known preference-aversion curves for produced made thirsty water deprivation. These findings indicate injections, like normal thirst, produce motivated behavior not mere reflexive drinking. 2 body fluid tissue analyses revealed there no changes plasma volume or osmolarity associated with injections. which follows cholinergic stimulations are due direct activation central neural structures controlling balance secondary systemic alterations fluids.