BACKGROUND AND PURPOSE: The aim of this study was to explore the effects of CB(2) receptor agonist and antagonist in the regulation of @entity148 -like behaviours. EXPERIMENTAL APPROACHES: Effects of acute and chronic treatment with the CB(2) receptor agonist @entity26405 and CB(2) receptor antagonist @entity36054 were evaluated in the light-dark box (LDB) and elevated plus maze (EPM) tests in Swiss ICR @entity19 . CB(2) receptor, @entity1246 (A) a(2) and @entity1246 (A) y(2) gene and protein expression in the cortex and amygdala of @entity19 chronically treated with @entity26405 or @entity36054 were examined by RT-PCR and Western blot. Effects of chronic @entity36054 treatment were evaluated in spontaneously anxious DBA/2 @entity19 in LDB. KEY RESULTS: Acute @entity26405 treatment failed to produce any effect. Acute @entity36054 treatment increased @entity148 and was blocked by pre-treatment with @entity26405 . Chronic @entity26405 treatment increased @entity148 -like behaviour whereas chronic @entity36054 treatment was anxiolytic in LDB and EPM tests. Chronic @entity36054 treatment increased gene and reduced protein expression of CB(2) receptors, @entity1246 (A) a(2) and @entity1246 (A) y(2) in cortex and amygdala. Chronic @entity26405 treatment resulted in opposite gene and protein alterations. In addition, chronic @entity36054 administration decreased the @entity148 of @entity7840 /2 @entity19 in the LDB test. CONCLUSIONS AND IMPLICATIONS: The opposing behavioural and molecular changes observed after chronic treatment with @entity36054 or @entity26405 support the key role of CB(2) receptors in the regulation of @entity148 . Indeed, the efficacy of @entity36054 in reducing the @entity148 of the spontaneously anxious DBA/2 strain of @entity19 strengthens the potential of the CB(2) receptor as a new target in the treatment of @entity148 .

Chronic blockade of cannabinoid CB2 receptors induces anxiolytic-like actions associated with alterations in XXXX (A) receptors.

@entity36054 :: ('MESH:C094023', 'Chemical') :: ['AM630'] @entity1246 :: ('MESH:D005680', 'Chemical') :: ['GABA'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity26405 :: ('MESH:C432747', 'Chemical') :: ['JWH133'] @entity148 :: ('MESH:D001008', 'Disease') :: ['anxiety-related disorders', 'anxiety'] @entity7840 :: ('CHEBI:35299', 'Chemical') :: ['DBA']
@entity1246 :: (MESH:D005680,Chemical) :: ['GABA']
