POLYAMINE-LIKE IMMUNOREACTIVITY IN RAT NEURONS

The localization of polyamine (PA) pools in motor, sensory, and autono mic neurons and in the nerve cells of the hypothalamo-hypophysial syst em of rats was examined by immunocytochemical method using the monoclo nal antibody ASPM-29 specific to spermine (Spm) and spermidine (Spd) f ixed in situ. Strong PA immunoreactivity was found in the cytoplasm an d dendrites of the large perikaryon of motor neurons in the anterior s pinal column, in the Purkinje cells of the cerebellum, in the pyramida l cells of the cerebrum, in the nerve cells of the paraventricular and supraoptic nuclei in the hypothalamus, and in the nerve cells of the spinal and autonomic ganglions. No PA immunoreactivity was seen in the nucleus and nerve terminals of the neurons. The PA immunoreactivities in the motor and sensory neurons were characterized by clustered mass es and blocks of immunoreactive cells. Irrespective of location, small and medium-sized neurons were weakly PA-positive. The glia cells, som e stellite cells, and Schwann cells were almost completely PA-negative . These results may suggest that in neurons PAs are not transported ax onally, but are located in conjunction with Nissl bodies (the rough en doplasmic reticulum), specified as sites for protein synthesis within cells. (C) 1997 Elsevier Science B.V.