Regeneration of supraspinal projection neurons in the adult goldfish

Regenerating descending axons preferentially reroute to the gray matter in the presence of a general macrophage/microglial reaction caudal to a spinal transection in adult zebrafish

“…The lack of regeneration in certain tracts is in agreement with the fact that neurons in some brain nuclei could not be labeled retrogradely after a spinal lesion in goldfish (Sharma et al, 1993). However, it is not clear whether the brain nuclei that contained neurons that did not to regenerate according to the report by Sharma et al (1993) actually projected in the ventral funiculus, for which a lack of axonal regeneration has been described by Bunt and FillMoebs (1984).…”

“…In contrast, in the closely related goldfish, it has been concluded from a set of similar tracing experiments that axons of the lateral funiculi regrew into their former location in the caudal spinal cord rather than into the gray matter and that axons of the ventral funiculi did not regrow into the spinal cord caudal to the lesion site at all (Bunt and Fill-Moebs, 1984). The lack of regeneration in certain tracts is in agreement with the fact that neurons in some brain nuclei could not be labeled retrogradely after a spinal lesion in goldfish (Sharma et al, 1993). However, it is not clear whether the brain nuclei that contained neurons that did not to regenerate according to the report by Sharma et al (1993) actually projected in the ventral funiculus, for which a lack of axonal regeneration has been described by Bunt and FillMoebs (1984).…”

Axonal regeneration of descending brain neurons in larval lamprey demonstrated by retrograde double labeling

“…However, in embryonic and early postnatal periods, spinal cord injury can result in restoration of descending projections and recovery of function (Shimizu et al, 1990;Hasan et al, 1991;Saunders et al, 1992;Treherne et al, 1992), although sometimes by aberrant pathways (Reh and Kalil, 1982;Bregman and Goldberger, 1982; see also Borgens et al, 1990). In lamprey, fish, and some amphibians, after spinal cord transection, descending axons from brain neurons grow through the transection site and make functional synaptic connections with spinal neurons below the lesion, during which time there is gradual restoration of locomotor function (Hooker, 1925;Piatt, 1955;Bernstein and Gelderd, 1970;Rovainen, 1976;Selzer, 1978;Coggeshall et al, 1982;Coggeshall and Youngblood, 1983;Clarke et al, 1988;Davis et al, 1989a;Beattie et al, 1990;Sharma et al, 1993; for reviews, see McClellan, 1992McClellan, , 1994bMcClellan, , 1998.…”

Experimental strategies to promote axonal regeneration after traumatic central nervous system injury

“…The poor axonal regeneration in mammalian CNS stands in sharp contrast with the situation observed in ®sh, amphibia or mammalian peripheral nervous system (PNS) and immature mammalian CNS. The latter systems possess signi®cant regenerative capacities and are able to restore neuronal function after lesion (Ramo n y Cajal, 1928;Gaze, 1970;Kiernan, 1979;Cohen et al, 1988;StuÈ rmer et al, 1992;Sharma et al, 1993;Davis and McCellan, 1994;Lang et al, 1995;. At the beginning of this century, the regeneration failure of CNS was a dogma and dierentiated mammalian CNS neurons were considered inherently incapable of regrowth.…”