Effects of cerebral lesions on binding sites for calcitonin and calcitonin gene-related peptide in the rat nucleus accumbens and ventral tegmental area.
Binding site densities of [125I]-labelled salmon calcitonin and human calcitonin gene-related peptide were investigated in the rat nucleus accumbens and ventral tegmental area by means of quantitative autoradiography following selective brain lesions. [125I]salmon calcitonin and [125I]human calcitonin gene-related peptide binding sites were highly concentrated in the accumbens, whereas the ventral tegmental area only contained [125I]salmon calcitonin binding sites. Unilateral injection of 6-hydroxydopamine into the ventral tegmental area did not alter [125I]salmon calcitonin and [125I]human calcitonin gene-related peptide binding site densities in the ipsilateral accumbens, while it produced a significant decrease in [125I]salmon calcitonin binding sites in the lesioned ventral tegmental area (-50%). In contrast, following unilateral injection of quinolinic acid into the accumbens, the densities of [125I]salmon calcitonin and [125I]human calcitonin gene-related peptide binding sites were significantly decreased in the lesioned accumbens (-57% and -56%, respectively), while [125I]salmon calcitonin binding site densities were not modified in the ipsilateral ventral tegmental area. The present study clearly suggests that [125I]salmon calcitonin and [125I]human calcitonin gene-related peptide binding sites are located on intrinsic neurons but not on the dopaminergic nerve terminals in the accumbens. Moreover, a certain proportion of [125I]salmon calcitonin binding sites could be present on dopaminergic cell bodies in the ventral tegmental area.
Masuo
Y
Y
INSERM U.339, Hôpital Saint-Antoine, Paris, France.
Giscard-Dartevelle
S
S
Bouizar
Z
Z
Rostène
W
W
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002116:Calcitonin / Q000378:metabolism; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D006801:Humans; D008297:Male; D009714:Nucleus Accumbens / Q000378:metabolism*; D016627:Oxidopamine / Q000494:pharmacology*; D017378:Quinolinic Acid; D011805:Quinolinic Acids / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface / Q000378:metabolism*; D013681:Tegmentum Mesencephali / Q000378:metabolism*
D011805:Quinolinic Acids; D018003:Receptors, Calcitonin; D011956:Receptors, Cell Surface; C028815:salmon calcitonin; D016627:Oxidopamine; D002116:Calcitonin; D017378:Quinolinic Acid; D015740:Calcitonin Gene-Related Peptide