Upregulation of cytosolic branched chain aminotransferase in substantia nigra following developmental striatal target injury

We have previously shown that apoptotic cell death can be induced in substa ntia nigra (SN) by developmental striatal target lesion. In this model, onl y a portion of nigral neurons dies, so it provides a paradigm to examine no t only the molecular basis of cell death, but also the cellular responses o f adjacent neurons which survive. Using a differential display approach, we have found that cytosolic branched chain aminotransferase (BCATc) mRNA is upregulated in SN in this model. This upregulation is associated with an in creased number of BCATc-positive neuronal profiles, demonstrated by immunos taining. BCATc-positive neurons show normal morphology and rarely contain a poptotic chromatin. We conclude that BCATc is upregulated in neurons, which are likely to survive, and plays a role in either maintenance of viability or restoration of normal function. (C) 2000 Published by Elsevier Science B.V. All rights reserved.