Reduced mRNA expression of neuropeptide Y in the limbic system of tenascin gene disrupted mouse brain.

Tenascin-C (TN), an extracellular matrix glycoprotein which reveals both neurite outgrowth-promoting and growth-inhibiting effects, is generated in the central nervous system. A previous study reported that TN-gene null mutant mice display hyperlocomotion and do not easily habituate to unfamiliar environments. Additionally, these mice display poor appetite, abnormal circadian rhythm and low pregnancy rate. The present study demonstrated that neuropeptide Y (NPY) mRNA expression is reduced in the limbic area of the TN gene-deficient mouse brain as compared to wild-type mice. NPY has been shown to affect emotion, circadian rhythm and food intake, and the present results suggest that the some behavioural abnormalities exhibited by TN-mutant mice may be in part due to the low level of expression of NPY mRNA in the limbic system.