PVALB and spinocerebellar ataxia type 1: Thus, Pilotto and associates (2023) recently reported that Purkinje cell degeneration in spinocerebellar ataxia type 1 (SCA1) can be related to increased activity of molecular layer interneurons, which are characterized by elevated levels of parvalbumin expression and an imbalanced excitatory-to-inhibitory synaptic investment.