Korean J Physiol Pharmacol.  2001 Dec;5(6):479-485.

Mediation of N-methyl-D-aspartate on neuropeptide Y expression induced by morphine in mouse cerebellum

• Kwon GY
• Kim SK

Abstract

The existence of opioid receptors in mammalian cerebellum except human, has not been clearly understood. In the present study, we found that NPY was inducible by morphine in the mouse cerebellar granular and Purkinje cell layers. We performed in situ RT-PCR and immunohistochemistry to characterize the NPY expression. The increase of NPY gene expression by morphine (30 mg/kg, i.p.) was inhibited by pretreatment with not only naloxone (100 mg/kg, i.p.) but also a noncompetitive NMDA antagonist, MK-801 (0.3 mg/kg, i.p.). The competitive NMDA antagonist, AP-5 (0.9 mg/kg, i.p.) slightly attenuated the increased NPY expression by morphine. Also, the finding similar to morphine was shown by NMDA (70 mg/kg, i.p.) treatment. Our results indicate that NPY was inducible by morphine and this might reflect activation of NMDA receptors in granule cells that relay mossy fiber inputs to Purkinje cells via parallel fibers.

MeSH Terms

Animals
Cerebellum*
Dizocilpine Maleate
Gene Expression
Humans
Immunohistochemistry
Mice*
Morphine*
N-Methylaspartate*
Naloxone
Negotiating*
Neuropeptide Y*
Neuropeptides*
Purkinje Cells
Receptors, N-Methyl-D-Aspartate
Receptors, Opioid
Dizocilpine Maleate
Morphine
N-Methylaspartate
Naloxone
Neuropeptide Y
Neuropeptides
Receptors, N-Methyl-D-Aspartate
Receptors, Opioid