Age- and sex-related expression of norbin in the brain cortex of mice

Norbin is a novel neuron specific protein that extends the neurites of neur onal cells. It is expressed in neural tissues like brain cortex, hippocampu s, spinal cord and cerebellum. In this paper, we have studied the expressio n of norbin mRNA and protein in the brain cortex of male and female mice of different ages. Northern blot analysis showed that the level of norbin mRN A increased in both sexes during aging. However, Western blotting revealed that the protein increased in male but decreased in female with advancing a ge. These findings suggest that norbin is involved in brain function which is dependent on age and sex. (C) 2001 Elsevier Science Ireland Ltd. All rig hts reserved.