Immunocytochemical and Ultrastructural Study of Localization of the γ-Aminobutyraldehyde Dehydrogenase in the Bovine Brain

Abstract

γ-Aminobutyraldehyde dehydrogenase (γ-ABALDH), is an enzyme which catalyses the dehydrogenation of γ- minobutyraldehyde (ABAL) to γ-aminobutyric acid (GABA), an inhibitory neurotransmitter in the mammalian central nervous system. To investigate the ultrastructural location of γ-ABADL in bovine brain, immunocytochemical staining for electron microscopical observation was done using anti-γ -ABALDH antibodies. Immunoreactive particles with high electron density were observed in the perikarya of neurons. In unmyelinated and thin myelinated nerve fibers, highly electron dense materials were observed not only around the microtubules and mitochondrial membrane, but also in the mitochondrial matrix. Cells containing γ-ABALDH, found in many regions of bovine brain tissues, were mostly small and medium-sized neurons, generally known as intemeurons. Ultrastructurally, the γ-ABALDH was determined to be distributed mainly in the cytoplasm and around the membranes of the endoplasmic reticulum and the mitochondria.