Altered striatal rhythmic activity in cylindromatosis knock-out mice due to enhanced GABAergic inhibition

Despite the highest expression in striatum, physiological function of cylindromatosis (CYLD), a deubiquitinating enzyme, remains unexplored. We found, in the present study, that the duration of spontaneous up-states in the striatum is shorter and membrane potential fluctuation preceding action potential and firing rate are increased in Cyld(-/-) mice. Excess striatal GABAergic inhibition likely plays the major role in this alteration as supported by the findings: (1) the levels of striatal GABAA and GABAB receptors in Cyld(-/-) mice are increased, (2) pharmacological blockade of GABAB receptors rescues the shortened up-state phenotype, and (3) pharmacological blockade of GABAA receptors rescues the power of beta frequency oscillations. Our results indicate that CYLD alters striatal network function by regulating the protein expression levels of GABA receptors.