The effects of central administration of neuropeptide Y on behavior of tenascin-gene knockout mice.

Tenascin-C (TN), an extracellular matrix glycoprotein, plays a pivotal role in the regulation of neuronal pattern formation. TN-gene deficient mice produced by homologous recombination show hyperlocomotive activities. We have recently demonstrated that neuropeptide Y (NPY) mRNA expression is reduced in the limbic area of the TN-gene knockout mouse brain, compared to that in wild-type mice. We now report the effect of NPY on the behavior of TN mutant mice. Intracerebroventricular injection of NPY transiently decreased the hyperlocomotion of TN mutant mice. Concurrently, mice given NPY showed anxiolytic behavioral change as assessed by an exploratory model. The results presented here suggest that the hyperlocomotion of TN mutant mice is partially derived from severe tensity.