Distribution of nadph-diaphorase positive structures of olfactory bulb of rats in ontogenesis

Aim: to identify peculiarities of distribution of NADPH-diaphorase (NADPH-d) positive structures in olfactory bulbs of rats of different age.

Materials and Methods. The study was conducted on 22 white male rats. The object of research was olfactory bulbs of newborn rats – 1-3 days, suckling period – 7, 14, 21 days, infantile – 30 days, juvenile – 60, and mature – 180 days. The study was conducted on cryostat serial sections of olfactory bulbs (20 µm). Nitroxidergic structures were identified by histochemical labelling of NADPH-d (by Hope method). In a standard section, the area of NADPH-diaphorase-positive cells (100 in each case), surface area of glomeruli, the number of positive neurons surrounding a glomerulus, were measured.

Results. In result of study it was found that in the olfactory bulb of rats of the studied age only groups of superficial and deep short-axon neurons and periglomerular neurons showed positivity to NADPH-d. The end product of reaction was distributed in somas and extensions of a part of cells with the density of distribution depending on the layer of the olfactory bulb and on the age of animals. Besides, positivity to the enzyme was also found in the central parts of glomeruli with distribution of diaphorase depending not on age, but rather on localization of glomeruli.

Conclusion. Age-related transformations of positive subpopulation of neurons of olfactory bulb indicate active participation of NO in the processes of postnatal differentiation, growth and development of olfactory bulb.