Nuclear localization of alpha-synuclein induces anxiety-like behavior in mice by decreasing hippocampal neurogenesis and pathologically affecting amygdala circuits

•Overexpression of α-syn in the hippocampal neuronal nuclei led to anxiety-like behavior in mice.•Nuclear localization of α-syn activated NG2 glial cells and promotes the synthesis and release of GABA in the hippocampus.•Nuclear localization of α-syn induced the loss of neurotrophic factors, and decreased neurogenesis.•α-syn diffused to the amygdala resulting in pathologic accumulation of α-syn and gliosis and caused loss of interneurons.