MELANOCORTINS AND LESION-INDUCED PLASTICITY IN THE CNS - A REVIEW

This review summarises and critically evaluates the literature pertain ing to the actions of short fragments of the adrenocorticotropic hormo ne (ACTH) ('melanocortins') on lesion-induced plasticity in the centra l nervous system (CNS). The majority of the evidence suggests that mel anocortins are more effective in enhancing recovery from lesions of su bcortical structures than cortical structures, although there is subst antial variability in findings depending upon the specific ACTH fragme nt used and the way in which it is administered. Five specific melanoc ortin (MC) receptors have been identified, however, the evidence to da te suggests that short ACTH fragments may not enhance lesion-induced p lasticity in the CNS via these MC receptor subtypes. It is possible th at another, as yet unidentified, MC receptor subtype is involved, or e lse that some short ACTH fragments act allosterically on another recep tor type (e.g., the N-methyl-D-asparate (NMDA) receptor).