摘要：SummarySLITRK2 encodes a transmembrane protein that modulates neurite outgrowth and synaptic activities and is implicated in bipolar disorder. Here, we addressed its physiological roles in mice. In the brain, the Slitrk2 protein was strongly detected in the hippocampus, vestibulocerebellum, and precerebellar nuclei—the vestibular-cerebellar-brainstem neural network including pontine gray and tegmental reticular nucleus. Slitrk2 knockout (KO) mice exhibited increased locomotor activity in novel environments, antidepressant-like behaviors, enhanced vestibular function, and increased plasticity at mossy fiber–CA3 synapses with reduced sensitivity to serotonin. A serotonin metabolite was increased in the hippocampus and amygdala, and serotonergic neurons in the raphe nuclei were decreased in Slitrk2 KO mice. When KO mice were treated with methylphenidate, lithium, or fluoxetine, the mood stabilizer lithium showed a genotype-dependent effect. Taken together, Slitrk2 deficiency causes aberrant neural network activity, synaptic integrity, vestibular function, and serotonergic function, providing molecular-neurophysiological insight into the brain dysregulation in bipolar disorders.Graphical abstractDisplay OmittedHighlights•Slitrk2 KO mice showed antidepressant-like behaviors and enhanced vestibular function•Mossy fiber-CA3 synaptic sensitivity to serotonin was reduced in Slitrk2 KO mice•Serotonin metabolite was increased in hippocampus and amygdala of Slitrk2 KO mice•Numbers of serotonergic neurons in raphe nuclei were decreased in Slitrk2 KO miceCell biology; Molecular physiology; Neuroscience
