Avtor/Urednik		Bajrović, Fajko; Sketelj, Janez
Naslov		Extent of nociceptive dermatomes in adult rats is not primarily maintained by axonal competition
Tip		članek
Vir		Exp Neurol
Vol. in št.		Letnik 150, št. 1
Leto izdaje		1998
Obseg		str. 115-21
Jezik		eng
Abstrakt		Nociceptive innervation territories of individual peripheral and spinal nerves in the skin of the rat hind paw were investigated. In addition, the hypothesis that competitive interactions among the axons from adjacent dorsal root ganglia (DRG) play an important role in maintenance of dermatomal extent in adult animals was tested. The area of innervation territories of individual spinal and peripheral nerves was determined by nociceptive pinch test of the skin after extirpation of adjacent DRGs or transection of adjacent peripheral nerves, respectively. Positions of nociceptive dermatomes and innervation territories of peripheral nerves were similar to the territories innervated by the C-fibers described earlier by dye extravasation tecnique. In contrast, our results convincingly demonstrated substantial overlap of nociceptive (probably A delta) fibers from adjacent dermatomes in which the autonomous innervation areas were only about onehalt of the maximal areas. nociceptive territories of peripheral nerves overlapped, too. Accordingly, we could find no autonomous innervation area of the sural nerve. Two weeks after extirpation of adjacent DRGs, the area of each of the isolated dermatomes L3, L4, and L5 increased only by about 10%, and it did not change detectably during the next 6 months. The results of our study (a) support the view that innervation fields supplied by the nociceptive (probably A delta) fibers are grater and display more overlap than those supplied by the C-fibers of the same nerve and (b) suggest that axonal competition for innervation territory is not decisive for maintenance of dermatomal borders in the adult rat.
Deskriptorji		AXONS GANGLIA, SPINAL HINDLIMB PAIN NEURONS, AFFERENT RATS, WISTAR PERONEAL NERVE SCIATIC NERVE SKIN FOOT SPINAL CORD SURAL NERVE TIBIAL NERVE TOES