Yp. Xin et al., DISTRIBUTION IN THE CENTRAL-NERVOUS-SYSTEM OF APLYSIA OF AFFERENT-FIBERS ARISING FROM CELL-BODIES LOCATED IN THE PERIPHERY, Journal of comparative neurology, 359(4), 1995, pp. 627-643
The present study used autoradiography to determine the location of th
e projections of presumptive peripheral afferent neurons into the cent
ral nervous system of Aplysia. Selected peripheral tissues (with an em
phasis on structures involved in feeding behavior) were exposed to rad
ioactive amino acids, and the distribution of macromolecules transport
ed into the nervous system via afferent fibers was determined by autor
adiography. Different regions of the body exhibited different patterns
of projections, and, within the neuropil of the cerebral ganglion, th
ere was a loose topographical organization of projections from the hea
d. For some regions of the body, the projection was largely limited to
the ganglion from which the nerve enters; for other regions, the proj
ection was very widespread. In some cases (e.g., rhinophore to eye), t
here was evidence of projections from one peripheral structure to anot
her. Experiments with all peripheral tissues that were studied resulte
d in extensive labeling of central ganglia, indicating that afferents
with peripheral cell bodies may provide a major source of sensory inpu
t to the central nervous system and suggesting that many or all of the
numerous ultrafine axons visualized via electron microscopy in the ne
rves of Aplysia may originate from first- or second-order sensory affe
rents whose cell bodies are located in the periphery. (C) 1995 Wiley-L
iss, Inc.