Mechanisms by which diazepam, muscimol, and other drugs change the content of cGMP in cerebellar cortex

Abstract

The cyclic[c]GMP content of the cerebellar cortex is altered by drugs that change either the excitatory input of climbing or mossy fibers or the inhibitory input mediated by the activation of .gamma.Abu (.gamma.-aminobutyric acid) receptors. Mechanisms by which various drugs alter the cerebellar content of cGMP were investigated. By using various experimental designs, diazepam and muscimol lowered the cGMP content by activating .gamma.-Abu receptors. Morphine and haloperidol lowered the cerebellar cortex cGMP by decreasing the excitation of mossy fibers whereas harmaline increased the cGMP by increasing the excitation of the climbing fibers.