Format

Send to:

Choose Destination
See comment in PubMed Commons below
Brain Res. 1997 Feb 28;749(2):263-74.

Mouse cerebellar adenosinergic modulation of ethanol-induced motor incoordination: possible involvement of cAMP.

Author information

  • 1Department of Pharmacology, School of Medicine, East Carolina University, Greenville 27858, USA.

Abstract

As an extension of our previous work pertaining to brain adenosinergic modulation of ethanol-induced motor incoordination, the effect of direct intracerebellar administration of the A1-selective adenosine agonist, N6-cyclohexyladenosine (CHA) on ethanol-induced motor incoordination was evaluated. Marked accentuation of ethanol-induced motor impairment by CHA was observed. No change in the normal motor coordination was noted when CHA administration was followed by saline instead of ethanol. Intracerebellar cAMP or its analog, 8-(4-chlorophenylthio)-cAMP, significantly inhibited ethanol's motor impairment in a dose-related manner as well as abolished CHA's accentuating effect on ethanol-induced motor incoordination. These observations suggested a possible involvement of cAMP in the adenosinergic modulation and in the expression of ethanol-induced motor incoordination. Further support was provided by the observation of a marked accentuation and attenuation in a dose-related manner of ethanol-induced motor impairment as well as CHA's accentuation of ethanol's motor impairment by intracerebellar miconazole and forskolin, respectively. However, equimolar intracerebellar doses of miconazole and forskolin (inhibitor and stimulator of adenylyl cyclase, respectively) failed to significantly alter ethanol-induced motor incoordination probably due to their mutual functional antagonism. The expression of adenosinergic modulation and that of ethanol-induced motor impairment most likely involved Gi protein-coupled receptor(s) (such as adenosine receptors). The involvement of receptors linked to pertussis toxin-sensitive G-proteins was suggested because intracerebellar pertussis toxin pretreatment markedly inhibited ethanol-induced motor incoordination as well as CHA's accentuation of ethanol's motor impairment. Finally, cAMP, unlike its antagonism to CHA's accentuation, failed to antagonize the accentuation of ethanol-induced motor impairment by intracerebellar GABA(A) agonist (+)-muscimol. This indicated selectivity of cAMP participation in G protein coupled receptor (such as adenosine)-mediated response and not in ionic channel coupled receptor (such as GABA(A))-mediated mechanism. Overall, the data suggested a possible involvement of cerebellar adenylyl cyclase-cAMP signalling pathway in the adenosinergic modulation of ethanol's ataxia.

PMID:
9138726
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk