Nitric oxide-evoked cGMP production in Purkinje cells in rat cerebellum: An immunocytochemical and pharmacological study

The cerebellar cells that account for glutamate-dependent cyclic GMP (cGMP) production, involving activation of the ionotropic glutamate receptors/nitric oxide synthase/soluble guanylyl cyclase pathway, are not fully established. In the present paper we have searched for the localisation of the cGMP response to the nitric oxide (NO) donor S-nitroso-penicillamine (SNAP 1 μM), expected to generate local NO concentrations in the low nanomolar physiological range and evoking a cGMP response dependent on glutamate release and on the consequent activation of ionotropic glutamate NMDA/non-NMDA receptors, in cerebellar slices from adult rat. We have found that low concentration of exogenous NO evoked cGMP accumulation in Purkinje cells in an ionotropic glutamate receptor-dependent and tetrodotoxin-sensitive manner. Such immunocytochemical localisation appears consistent with functional evidence for physiologically relevant glutamate-dependent cGMP production in Purkinje cells in rat cerebellar cortex.