Connections of the olfactory bulb in the piranha (Serrasalmus nattereri).
The connections of the olfactory bulb were studied in the piranha using the Nauta and horseradish-peroxidase methods. Three olfactory tracts project to seven terminal fields in the telencephalon and one in the diencephalon, all of them bilaterally. The contralateral olfactory bulb also receives a small input. All contralateral projections decussate in the anterior commissure and are relatively weak compared to the ipsilateral projections. HRP-containing cells were found in all of the ipsilateral telencephalic aggregates receiving an olfactory tract projection; the contralateral side was free of labeled cell bodies. Although only about one fourth of the entire telencephalon receives a direct olfactory input, the high degree of differentiation of the olfactory system suggests that the piranha depends substantially on the sense of olfaction and that this species may be a good model for further studies on olfactory mechanisms.
D000818:Animals; D001931:Brain Mapping; D005399:Fishes / Q000033:anatomy & histology*; D007839:Functional Laterality; D009434:Neural Pathways / Q000166:cytology; D009830:Olfactory Bulb / Q000166:cytology*; D013045:Species Specificity; D013687:Telencephalon / Q000166:cytology