Reversibility of cerebellar GABAergic synapse impairment induced by anti-glutamic acid decarboxylase autoantibodies.

Anti-glutamic acid decarboxylase autoantibodies (GAD-Abs) are found in some patients with cerebellar ataxia. We reported previously that CSF IgGs depress cerebellar GABAergic synaptic transmissions by a presynaptic mechanism. Using whole-cell recordings from rat cerebellar slices, we found in the present study that CSF IgG-induced depressive effects were abolished by absorption of GAD-Abs using recombinant GAD. Furthermore, forskolin, an activator of cAMP, recovered the CSF IgG-induced reduction of GABA release. Our results provide evidence that GAD-Abs in the CSF elicited physiopathological effects on cerebellar GABA synapses in vitro and that such synaptic impairment was reversible.