Influence of toluene intoxication on the number of mitral and granular neurons in olfactory bulbs of rats.

In the last years, implementation of the volatile solvents in order to get a narcotic high, used via inhalation (sniffing), increased significantly, especially in the youth. Substances containing these agents induce hallucinations and euphoric state. In the present study the influences of toluene intoxication on quantity of the mitral and granular cells in olfactory bulbs was analyzed in young and adult rats. An inhalation route of intoxication was used in our experiments - animal inhaled toluene until attaining a sidewise laying position. This procedure was performed in the closed glass container, in which air was beforehand saturated with the toluene vapours. Experiments was carried out on two age groups (n=20 animals): one - and two months age rats. Inhalation period was 40 days. Each age group consisted of ten animals and was divided into the two subgroups: I - control animals (n=5), II - experimental animals (n=5). Assessment of the neurons' quantity in different structures was made according to the fractional approach method proposed by M. West (1999). The results obtained showed that number of mitral neurons in the olfactory bulb of the Subgroup II of the rats, sniffing since the age of one and two months, significantly decreased by 43% (p<0,05) and by 28% (p<0,01), respectively. Meanwhile, the granular cells remained unaltered in experimental animals of both age groups. Decrease of the projection mitral neurons, in its turn, results in disruption of the projections to olfactory cortex and hampers proper functioning of the olfactory analyzer.