Nonolfactory Telencephalic Afferents in the Nurse Shark (Ginglymostoma cirratum); pp. 121–138

The nonolfactory afferents to the telencephalon of the nurse shark were determined by tracking ascending degenerating fibers with silver impregnation techniques. Of the three ascending fiber bundles, the largest tract is entirely crossed and terminates in a central telencephalic nucleus. The smaller ipsilateral tract ascends laterally and terminates predominantly in the same cell group, but a few reach a more lateral region. The third group of ascending fibers is in the ventromedial bundle, and they terminate in basal areas primarily ipsilaterally but have a small contralateral component. At least a portion of the latter originate from levels caudal to the diencephalon. It can be concluded that the telencephalon of sharks is not entirely an olfactory structure but has similarities to mammalian thalamotelencephalic organization.