Ataxia.Epilepsy.Disruption of long-term potentiation.Loss of Parvalbumin interneurons.Reactive astrogliosis.Hippocampal neurogenesis is reduced. Depletion of SELENOP and its receptor ApoER2 results in spatial memory impairment in mice as well as defects in synaptic transmission.SELENOP-deficient mice exhibit selenium deficiency in the brain and myelin sheath abnormalities in the brainstem.Genetic deletion of SELENOP results in increased release of dopamine vesicles in response to methamphetamine. Here, SELENOP is linked to cerebellar ataxia.