Neuronal and glial localization of the cannabinoid-1 receptor in the superficial spinal dorsal horn of the rodent spinal cord.
Eur J Neurosci
; 30(2): 251-62, 2009 Jul.
Article
em En
| MEDLINE
| ID: mdl-19614976
ABSTRACT
A long line of experimental evidence indicates that endogenous cannabinoid mechanisms play important roles in nociceptive information processing in various areas of the nervous system including the spinal cord. Although it is extensively documented that the cannabinoid-1 receptor (CB(1)-R) is strongly expressed in the superficial spinal dorsal horn, its cellular distribution is poorly defined, hampering our interpretation of the effect of cannabinoids on pain processing spinal neural circuits. Thus, we investigated the cellular distribution of CB(1)-Rs in laminae I and II of the rodent spinal dorsal horn with immunocytochemical methods. Axonal varicosities revealed a strong immunoreactivity for CB(1)-R, but no CB(1)-R expression was observed on dendrites and perikarya of neurons. Investigating the co-localization of CB(1)-R with markers of peptidergic and non-peptidergic primary afferents, and axon terminals of putative glutamatergic and GABAergic spinal neurons we found that nearly half of the peptidergic (immunoreactive for calcitonin gene-related peptide) and more than 20% of the non-peptidergic (binding isolectin B4) nociceptive primary afferents, more than one-third and approximately 20% of the axon terminals of putative glutamatergic (immunoreactive for vesicular glutamate transporter 2) and GABAergic (immunoreactive for glutamic acid decarboxylase; GAD65 and/or GAD67) spinal interneurons, respectively, were positively stained for CB(1)-R. In addition to axon terminals, almost half of the astrocytic (immunoreactive for glial fibrillary acidic protein) and nearly 80% of microglial (immunoreactive for CD11b) profiles were also immunolabeled for CB(1)-R. The findings suggest that the activity-dependent release of endogenous cannabinoids activates a complex signaling mechanism in pain processing spinal neural circuits into which both neurons and glial cells may contribute.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Neuroglia
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Células do Corno Posterior
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Receptor CB1 de Canabinoide
Limite:
Animals
Idioma:
En
Revista:
Eur J Neurosci
Assunto da revista:
NEUROLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Hungria