UNASSIGNED: Behavioral sensitization to @entity1068 ( @entity167 ) manifests as a progressive and enduring @entity2915 with repeated drug exposure. However, not all @entity19 sensitize to @entity167 and the neuronal mechanisms mediating vulnerability and resistance to @entity167 sensitization remain unclear. We examined regional brain expression of the immediate early gene activity-regulated cytoskeleton-associated protein (Arc) in order to identify brain areas in which neuroplastic changes may contribute to the development and expression of @entity167 sensitization. Male DBA/2J @entity19 received 5 biweekly injections of @entity167 (2.2g/kg, i.p.) or saline (SAL). They were categorized as high- ( @entity8682 ) or @entity258 ( @entity258 ) on the basis of final locomotor activity scores. In both @entity258 and @entity8682 @entity19 sacrificed after the last sensitization injection, Arc expression was decreased throughout the brain in comparison to SAL animals. A similar pattern was seen in @entity19 sacrificed after an @entity167 challenge two weeks after the last sensitization injection. However in this cohort, Arc expression was significantly increased in the central amygdala (CeA) in @entity258 @entity19 and in SAL @entity19 receiving @entity167 for the first time. No significant increases in Arc expression were seen in brains of sensitized ( @entity8682 ) animals. These results indicate an acute @entity167 challenge results in different patterns of Arc expression in brains of @entity258 , @entity8682 , and SAL @entity19 . The dramatic increases in Arc expression in the CeA in @entity258 and SAL @entity19 showing little or no behavioral activation suggests that neural activity in this region may serve to inhibit the stimulant effects of @entity167 . The observation that @entity8682 @entity19 do not show increases in Arc expression with an @entity167 challenge suggests the possibility that increased tolerance to the Arc-inducing effects of @entity167 may be a factor in behavioral sensitization.

Localized brain differences in Arc expression between XXXX showing low vs. high propensity to @entity1068 sensitization.

@entity167 :: ('CHEBI:16236', 'Chemical') :: ['EtOH'] @entity19 :: ('10090', 'Species') :: ['mice'] @entity8682 :: ('MESH:C567159', 'Disease') :: ['HS'] @entity2915 :: ('MESH:D006948', 'Disease') :: ['increase in locomotor activity'] @entity258 :: ('MESH:D009800', 'Disease') :: ['LS', 'low-sensitized'] @entity1068 :: ('MESH:D000431', 'Chemical') :: ['ethanol']
@entity19 :: (10090,Species) :: ['mice']
