Abnormal Behavior and Neurotransmissions of Tenascin Gene Knockout Mouse

To examine the role of tenascin (TN)in vivo,we have produced mice in which the TN gene is inactivated. In behavioral studies, TN-knockout mice showed abnormal behavior such as hyperlocomotion and poor swimming ability. Biochemical analysis revealed that serotonin (5-HT) and dopamine (DA) transmission was decreased in the cerebral cortex, the hippocampus, or the striatum of TN-knockout mouse brain. The intraperitoneal administration of the DA receptor agonist, LY171555 (0.5 mg/kg, BW), inhibited the hyperlocomotion, and swimming behavior was transiently improved by the treatment with the 5-HT receptor agonist, 1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane hydrochloride. These findings suggest that TN may play an important role in neurotransmissions related to behavior.