Neurochemical markers of cells of the periventricular brain area in the masu salmon Oncorhynchus masou (Salmonidae)

Localization of GABA, tyrosine hydroxylase (TH), NADPH-diaphorase, transcription factor Pax6, and the proliferative cell nuclrar antigen (PCNA) in the periventricular area of the brain of the masu salmon Oncorhynchus masou of varying age groups was studied. The presence of heterogeneous cell populations with radially orientated outgrowths in the diencephalon, central gray matter of the dorsomedial tegmentum, medulla oblongata, and spinal cord of the masu salmon was shown. TH-, GABA-immunopositive, and NADPH-d-positive cells are located in the areas of PCNA-immunogenic proliferative zones. It is possible that these cells are descendants of the radial neuroglia and that they participate in the growth and physiological regeneration of diencephalic and medullar structures. In various age groups of the masu salmon, the marking of TH-, GABA, PCNA, and Pax6 reveals the neuromeric structure of the brain.