SEGREGATED DISTRIBUTION OF TH-IMMUNOREACTIVITY IN OLFACTORY GLOMERULI

ATYPICAL and typical olfactory glomeruli differ in their primary affer ents, centrifugal control and in some chemically identified subpopulat ions of interneurones. The distribution of tyrosine hydroxylase (TH)-i mmunopositive neurones in the periglomerular region of both typical an d atypical glomeruli has been studied using a double histochemical-imm unohistochemical method. A segregated distribution of TH-immunopositiv e cells was found among both types of glomeruli. TH-immunolabelled cel ls were more abundant (p < 0.05) in the atypical glomeruli. These data suggest that some neuronal subpopulations are related to specific pro perties of the glomerular physiology and they have a segregated distri bution in different subsets of glomeruli. Thus, catecholamines might b e involved in the processing of specific olfactory cues in atypical gl omeruli. This study presents new differences in the cellular compositi on of typical and atypical glomeruli.