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JERALD J. BERNSTEIN
111. TELENCEPHALON
A. Olfactory Bulb Anatomy
In the fish, as in other animals, the sensory receptors for olfaction
project to the olfactory bulb (Wilson and Westerman, 1967). The
axons of the cells from the bulb are the primary efferent axons of
the olfactory system and pass posteriorly into the telencephalon. In
most vertebrates the olfactory bulbs are located immediately adjacent
to the wall of the nasal cavities and thus the olfactory tracts are
short. However, in certain teleosts the olfactory bulbs are separated
from the telencephalon proper by a long olfactory tract (Fig. 3 )
Fig. 3. Dorsal (upper), lateral (middle), and longitudinal (lower) section
of a goldfish brain, Carassius auratus. The longitudinal section was stained with
gallocyanin and periodic acid-Schiff counterstain. Abbreviations: I, olfactory nerve;
11, optic nerve; Ac L, acoustic lobe of medulla oblongata; Cerb, cerebellum; Fac L,
facial lobe of medulla oblongata; Hyp, hypothalamus; Med, medulla oblongata; OB,
olfactory bulb; OT, optic tectum; Sp C, spinal cord; Teg, tegmentum; Tel, telencephalon; Thal, thalamus; Vag L Med, vagal lobe of medulla oblongata; and VC,
valvula cerebelli.