Light and electron microscope observations of aspartate aminotransferase (AATase) in the hippocampus revealed by histoenzymological and immunocytochemical methods.

Immunocytochemical and histoenzymological were used to determine the localization and activity of AATase respectively at light and electron microscopic levels. Ths histoenzymological method revealed AATase activity in synaptic vesicles and in mitochondria. Both methods detected AATase presence and activity in pre and post-synaptic sites. No simultaneous positive reaction was observed at pre and post-synaptic zones of a given synapses. The significance of these results are discussed in the present paper.