Chronic social isolation during adolescence augments catecholamine response to acute ethanol in the basolateral amygdala

Synapse. 2015 Aug;69(8):385-95. doi: 10.1002/syn.21826. Epub 2015 May 28.


Adolescent social isolation (SI) results in numerous behavioral alterations associated with increased risk of alcoholism. Notably, many of these changes involve the basolateral amygdala (BLA), including increased alcohol seeking. The BLA sends a strong glutamatergic projection to the nucleus accumbens and activation of this pathway potentiates reward-seeking behavior. Dopamine (DA) and norepinephrine (NE) exert powerful excitatory and inhibitory effects on BLA activity and chronic stress can disrupt the excitation-inhibition balance maintained by these catecholamines. Notably, the impact of SI on BLA DA and NE neurotransmission is unknown. Thus the aim of this study was to characterize SI-mediated catecholamine alterations in the BLA. Male Long Evans rats were housed in groups of four (GH) or in SI for 6 weeks during adolescence. DA and NE transporter levels were then measured using Western blot hybridization and baseline and ethanol-stimulated DA and NE levels were quantified using microdialysis. DA transporter levels were increased and baseline DA levels were decreased in SI compared to GH rats. SI also increased DA responses to an acute ethanol (2 g kg(-1)) challenge. While no group differences were noted in NE transporter or baseline NE levels, acute ethanol (2 g kg(-1)) only significantly increased NE levels in SI animals. Collectively, these SI-dependent changes in BLA catecholamine signaling may lead to an increase in BLA excitability and a strengthening of the glutamatergic projection between the BLA and NAc. Such changes may promote the elevated ethanol drinking behavior observed in rats subjected to chronic adolescent stress.

Keywords: basolateral amygdale; dopamine; ethanol; microdialysis; norepinephrine; social isolation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Basolateral Nuclear Complex / drug effects*
  • Basolateral Nuclear Complex / growth & development
  • Basolateral Nuclear Complex / metabolism
  • Blotting, Western
  • Central Nervous System Depressants / pharmacology*
  • Chromatography, High Pressure Liquid
  • Chronic Disease
  • Disease Models, Animal
  • Dopamine / metabolism*
  • Dopamine Plasma Membrane Transport Proteins / metabolism
  • Ethanol / pharmacology*
  • Extracellular Space / drug effects
  • Extracellular Space / metabolism
  • Male
  • Microdialysis
  • Norepinephrine / metabolism*
  • Norepinephrine Plasma Membrane Transport Proteins / metabolism
  • Random Allocation
  • Rats, Long-Evans
  • Social Isolation*


  • Central Nervous System Depressants
  • Dopamine Plasma Membrane Transport Proteins
  • Norepinephrine Plasma Membrane Transport Proteins
  • Ethanol
  • Dopamine
  • Norepinephrine