Selective effects of partial and severe lesions of the serotonergic systems on Met-enkephalin and substance P neurons in rat basal ganglia. - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Molecular Brain Research Année : 1997

Selective effects of partial and severe lesions of the serotonergic systems on Met-enkephalin and substance P neurons in rat basal ganglia.

Résumé

The effects of partial (80%) vs. severe (> 95%) depletion of serotonin (5-HT) on peptide expression in basal ganglia were examined using immunocytochemical and in situ hybridization histochemical approaches. Topographical analysis of the changes in Met-enkephalin (Met-enk) and substance P (SP) levels were performed on the rat striatum, globus pallidus and substantia nigra 3 weeks after injecting 3 microl (partial lesion) or 6 microl (severe lesion) 5,7-dihydroxytryptamine (6.6 microg/microl) into the anterior raphe nuclei. Both kinds of lesion led to significant increases (39-42%) in Met-enk immunoreactivity in the striatum; a corresponding increase (21%) was detected in the globus pallidus only after severe 5-HT depletion. Only the severe lesion increased the SP immunoreactivity in the striatum (32%) and substantia nigra (26%). Neither striatal preproenkephalin nor preprotachykinin levels showed significant differences with the control values. These results suggest that the neuronal accumulation of Met-enk or SP may be attributable to post-transcriptional events, such as a blockade of the peptide release, and that 5-HT may, thus, exert a facilitatory influence on the striatal output neurons. The results obtained after partial lesion indicate a preferential sensitivity of striatal Met-enk vs. SP containing terminals to the 5-HT denervation. These differences are illustrated in selective regional changes in peptide labeling. These data point to some balance exerted by the serotonergic and dopaminergic inputs on these neuronal populations.

Domaines

Neurobiologie
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Dates et versions

hal-01667825 , version 1 (19-12-2017)

Identifiants

  • HAL Id : hal-01667825 , version 1
  • PUBMED : 9406941

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Valerie Compan, P. Salin, A. Daszuta. Selective effects of partial and severe lesions of the serotonergic systems on Met-enkephalin and substance P neurons in rat basal ganglia.. Molecular Brain Research, 1997, pp.246-56. ⟨hal-01667825⟩
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