TRANSFORMING GROWTH-FACTOR-ALPHA IMMUNOREACTIVITY IN THE DEVELOPING AND ADULT BRAIN

Transforming growth factor-alpha immunoreactivity is examined in the d eveloping and adult brain of cats and rats, and in the adult human bra in in cryostat sections immediately processed free-floating with a wel l-characterized monoclonal antibody which does not cross-react with ep idermal growth factor. Transforming growth factor-alpha immunoreactivi ty is observed in neurons of the cerebral neocortex, subiculum, hippoc ampus, striatum, thalamus, amygdala, basal forebrain, mesencephalon, c erebellar cortex, dentate nucleus and brainstem during development and in adulthood. The intensity of the immunoreaction directly correlates with the size of the cytoplasm. Diffuse transforming growth factor-al pha immunoreactivity also occurs in the white matter of the cerebrum, cerebellum and brainstem in the kitten, but not in the adult cat. In a ddition to neurons, numbers of glial cells in the cerebellar white mat ter, brainstem and cerebral hemispheres during development, and a few glial cells in the cerebellar cortex, diencephalon, cerebral cortex an d white matter in adults are strongly transforming growth factor-alpha immunoreactive. These results support the concept that transforming g rowth factor-alpha is widely distributed in the brain of mammals, loca lizes in both neurons and glial cells, and is development dependent. T hese findings also suggest that transforming growth factor-alpha may p lay a role in the developing and adult central nervous system.