Nigrostriatal dopamine neurons are required to maintain basal levels of substance P in the rat substantia nigra.
Striatal dopamine was depleted in adult rats by unilateral infusion of 6-hydroxydopamine near the dopamine neurons of the pars compacta of the substantia nigra. Following survival periods of 1, 3, 4, 6 or 12 weeks, changes in levels of the tachykinin neuropeptide, substance P, in striatonigral axon terminals were assessed by quantitative radioimmunocytochemistry. Substance P levels in the ipsilateral substantia nigra were consistently lower than levels on the control (non-lesion) side at every time point examined, reaching a maximum decline of about 30% at 3 weeks after the lesion. These data show that there is no recovery of nigral substance P content to basal levels up to 3 months post-lesion, and suggest strongly that intact striatal dopamine innervation is required for the maintenance of basal substance P levels in the terminals of striatonigral substance P neurons.
Cruz
C J
CJ
Department of Neuroscience, University of Virginia School of Medicine, Charlottesville 22908.
Beckstead
R M
RM
D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism / Q000502:physiology*; D006892:Hydroxydopamines; D008297:Male; D009498:Neurotoxins; D016627:Oxidopamine; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000378:metabolism*; D013378:Substantia Nigra / Q000378:metabolism*
D006892:Hydroxydopamines; D009498:Neurotoxins; D013373:Substance P; D016627:Oxidopamine; D004298:Dopamine