Effects of Ethanol Exposure During Adolescence or Adulthood on Locomotor Sensitization and Dopamine Levels in the Reward System

Author(s)

Carrara-Nascimento, Priscila Fernandes ^[1] ; Hoffmann, Lucas Barbosa ^[1] ; Florio, Jorge Camilo ^[2] ; Planeta, Cleopatra Silva ^[3] ; Camarini, Rosana ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Ciencias Biomed, Dept Farmacol, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Escola Med Vet, Dept Patol, Sao Paulo - Brazil

^[3] Univ Estadual Paulista, Fac Ciencias Farmaceut, Lab Neuropsicofarmacol, Araraquara, SP - Brazil

• Document type: Journal article
• Source: FRONTIERS IN BEHAVIORAL NEUROSCIENCE; v. 14, MAR 6 2020.
• Web of Science Citations: 0

Abstract

Behavioral sensitization is a process of neuroadaptation characterized by a gradual increase in motor behaviors. The major neural substrates involved in the behavioral sensitization lie on the dopaminergic mesocorticolimbic pathway, which is still under development during adolescence. To investigate age-differences in ethanol behavioral sensitization and dopamine levels in distinct brain regions of the reward system, adolescent and adult mice were repeatedly pretreated with saline or ethanol (2.0 g/kg i.p.) during 15 consecutive days and challenged with saline or ethanol 5 days after pretreatment. Dopamine and its metabolites were measured in tissue samples of the prefrontal cortex (PFC), nucleus accumbens (NAc) and striatum by HPLC analysis. While repeated ethanol administration resulted in the development of locomotor sensitization in both adult and adolescent mice, only the adults expressed sensitization to a subsequent ethanol challenge injection. Neurochemical results showed reduced dopamine levels in adolescents compared to adults. Specifically, mice pretreated with ethanol during adolescence displayed lower dopamine levels in the PFC compared to the respective adult group in response to an ethanol challenge injection, and preadolescent mice exhibited lower dopamine levels in the NAc following an acute ethanol treatment compared to adults. These findings suggest that adolescent mice are not only less sensitive to the expression of ethanol-induced sensitization than adults, but also show lower dopamine content after ethanol exposition in the PFC and NAc. (AU)

• FAPESP's process: 12/17228-1 - Alcohol dependence in adolescent mice in a model that considers pre-exposure and alcohol deprivation effect
• Grantee: Priscila Fernandes Carrara Do Nascimento
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/02397-0 - Study of environmental enrichment inducing a protective phenotype of behaviors that assess addictive features in mice
• Grantee: Rosana Camarini
• Support Opportunities: Regular Research Grants
• FAPESP's process: 12/10260-7 - Evaluation of CREB activation pathway in adolescent and adult mice treated with cocaine.
• Grantee: Rosana Camarini
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/11987-1 - Transgenerational epigenetic inheritance and environmental enrichment in male mice: investigation of hippocampus-dependent behaviors in the offspring and the involvement of epididymosomes
• Grantee: Lucas Barbosa Hoffmann
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 18/05038-0 - Effect of environmental enrichment on resilience to chronic unpredictable stress: epigenetic regulation of the BDNF gene and consequences on ethanol consumption
• Grantee: Rosana Camarini
• Support Opportunities: Regular Research Grants