Accelerated regeneration of central catecholamine fibers in cat occipital cortex: effects of substance P.
Remarkably fast regeneration of central noradrenaline (NA) fibers was recently observed in the 6-hydroxydopamine (6-OHDA)-perfused occipital cortex. In the present study, we found that this reinnervation by NA fibers was further accelerated by substance P (SP) perfused into the fourth ventricle but not by SP directly perfused into the cortex. The site of SP's action is therefore most likely located in the soma-dendritic area of NA cells in the locus coeruleus (LC). The regeneration-stimulating effect of SP seems to be mediated by a process specific to SP, since the similar treatment with bethanechol in place of SP was ineffective.
D000818:Animals; D018723:Bethanechol; D001626:Bethanechol Compounds / Q000494:pharmacology; D001927:Brain Diseases / Q000139:chemically induced / Q000188:drug therapy; D002415:Cats; D006651:Histocytochemistry; D006892:Hydroxydopamines; D008856:Microscopy, Fluorescence; D009638:Norepinephrine / Q000378:metabolism*; D009778:Occipital Lobe / Q000378:metabolism; D016627:Oxidopamine; D013373:Substance P / Q000627:therapeutic use*
D001626:Bethanechol Compounds; D006892:Hydroxydopamines; D018723:Bethanechol; D013373:Substance P; D016627:Oxidopamine; D009638:Norepinephrine