Mina G Nashed1, Dipashree Chatterjee2,3, Diana Nguyen2,3, Daria Oleinichenko2,3, Mustansir Diwan2, Jose N Nobrega2,3,4,5,6. 1. Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada. Mina.Nashed@camh.ca. 2. Behavioural Neurobiology Laboratory, Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada. 3. Departments of Psychology, University of Toronto, Toronto, ON, Canada. 4. Departments of Psychiatry, University of Toronto, Toronto, ON, Canada. 5. Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada. 6. Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada.
Abstract
RATIONALE: Ethanol-induced behavioural sensitization (EBS) does not occur uniformly in mice exposed to the sensitization paradigm. This suggests innate differential responses to ethanol (EtOH) in the reward circuitry of individual animals. OBJECTIVES: To better characterize the adaptive differences between low-sensitized (LS) and high-sensitized (HS) mice, we examined excitatory amino acid (EAA) and inhibitory amino acid (IAA) neurotransmitter levels in the nucleus accumbens (NAc) during EBS expression. METHODS: Male DBA/2J mice received five ethanol (EtOH) (2.2 g/kg) or saline injections, and locomotor activity (LMA) was assessed during EBS induction. EtOH mice were classified as LS or HS on the basis of final LMA scores. Following an EtOH challenge (1.8 g/kg) 2 weeks later, LMA was re-evaluated and in vivo microdialysis samples were collected from the NAc. RESULTS: Most differences in amino acid levels were observed within the first 20 min after EtOH challenge. LS mice exhibited similar glutamate levels compared with acutely treated (previously EtOH naïve) mice, and generally increased levels of the IAAs GABA, glycine, and taurine. By contrast, HS mice exhibited increased glutamate and attenuated levels of GABA, glycine, and taurine. CONCLUSION: These data suggest that the profile of amino acid neurotransmitters in the NAc of LS and HS mice significantly differs. Elucidating these adaptive differences contributes to our understanding of factors that confer susceptibility/resilience to alcohol use disorder.
RATIONALE: Ethanol-induced behavioural sensitization (EBS) does not occur uniformly in mice exposed to the sensitization paradigm. This suggests innate differential responses to ethanol (EtOH) in the reward circuitry of individual animals. OBJECTIVES: To better characterize the adaptive differences between low-sensitized (LS) and high-sensitized (HS) mice, we examined excitatory amino acid (EAA) and inhibitory amino acid (IAA) neurotransmitter levels in the nucleus accumbens (NAc) during EBS expression. METHODS: Male DBA/2J mice received five ethanol (EtOH) (2.2 g/kg) or saline injections, and locomotor activity (LMA) was assessed during EBS induction. EtOHmice were classified as LS or HS on the basis of final LMA scores. Following an EtOH challenge (1.8 g/kg) 2 weeks later, LMA was re-evaluated and in vivo microdialysis samples were collected from the NAc. RESULTS: Most differences in amino acid levels were observed within the first 20 min after EtOH challenge. LS mice exhibited similar glutamate levels compared with acutely treated (previously EtOH naïve) mice, and generally increased levels of the IAAs GABA, glycine, and taurine. By contrast, HS mice exhibited increased glutamate and attenuated levels of GABA, glycine, and taurine. CONCLUSION: These data suggest that the profile of amino acid neurotransmitters in the NAc of LS and HS mice significantly differs. Elucidating these adaptive differences contributes to our understanding of factors that confer susceptibility/resilience to alcohol use disorder.
Authors: Louise Adermark; Rhona B C Clarke; Torsten Olsson; Elisabeth Hansson; Bo Söderpalm; Mia Ericson Journal: Addict Biol Date: 2011-01 Impact factor: 4.280
Authors: S J Mihic; Q Ye; M J Wick; V V Koltchine; M D Krasowski; S E Finn; M P Mascia; C F Valenzuela; K K Hanson; E P Greenblatt; R A Harris; N L Harrison Journal: Nature Date: 1997-09-25 Impact factor: 49.962