The relationship between the dose of caffeine and the magnitude of conditioned reflex salivation in dogs]

Statistical estimates carried out on a comprehensive experimental material of the archives in the Laboratory of physiology of nervous system types at the Pavlov Institute of Physiology, USSR Academy of Sciences, made it possible to plot average static characteristics of changes in the magnitude of positive conditioned reflexes in dogs, depending on the dose of caffeine. It appeared that conditioned reflexes decreased to some extent after a 0.01 g dose; within the range of 0.05 to 1 g doses, the magnitude of reflexes increased to the maximum; within the range of 0.1 to 0.5 g, their magnitude diminished from the maximum to the normal level, and, finally, a dose of 0.5 g or greater resulted in a drop of the magnitude of the reflexes below the normal level.