APOPTOSIS IN AMYOTROPHIC-LATERAL-SCLEROSIS IS NOT RESTRICTED TO MOTOR-NEURONS - BCL-2 EXPRESSION IS INCREASED IN UNAFFECTED POST-CENTRAL GYRUS

We searched for the presence of apoptotic cell death and studied the d istribution of bcl-2, an oncoprotein that counteracts apoptosis, in am yotrophic lateral sclerosis (ALS). Brain and spinal cord specimens fro m 12 ALS patients were compared with those from six non-neurological c ontrols. ALS brain tissue was pre-selected by the presence of reactive cortical damage. Apoptosis was demonstrated by in situ end-labelling of fragmented DNA, a method that is suitable for formalin-fixed, paraf fin-embedded tissue. All ALS patients exhibited some apoptosis, eight of them did so in each of the three central nervous system (CNS)-level s studied. Apoptosis was not restricted to the motor system, but also affected other neuronal and non-neuronal CNS elements. Apoptosis corre sponded with cell shrinkage, and neuronophagia in Nissl stains and wit h small Nissl-positive bodies. None of the non-neurological controls s howed as much apoptosis as any of the ALS cases. Immunocytochemically, the overall distribution of Bcl-2 did not differ between ALS and non- neurological controls. In ALS, however, we found variable degrees of i ncreased Bcl-2 expressed in the nuclei and in the cytoplasm. We found no inverse relationship between apoptosis and bcl-2 expression.