Abnormal synaptic plasticity in basolateral amygdala may account for hyperactivity and attention-deficit in male rat exposed perinatally to low-dose bisphenol-A

Neuropharmacology. 2011 Apr;60(5):789-98. doi: 10.1016/j.neuropharm.2011.01.031. Epub 2011 Jan 28.


If the pregnant and lactating female rats are exposed to environmental levels of bisphenol-A (BPA), their male offspring will display hyperactivity and attention-deficit. In patients with attention-deficit/hyperactivity disorder (ADHD), the size of the amygdala is reported to be reduced. This study examined functional alterations in the basolateral amygdala (BLA) of the postnatal 28-day-old male offspring exposed perinatally to BPA (BPA-rats). We specifically focused on the synaptic properties of GABAergic/dopaminergic systems in the BLA. A single electrical stimulation of the capsule fibers evoked multispike responses with an enhanced primary population spikes (1st-PS) in the BPA-rats. A single train of high-frequency stimulation of the fibers induced NMDA receptor (NMDAR) dependent long-term potentiation (LTP) in BPA-rats, but not in control rats. Also, paired-pulse inhibition (PPI, GABA-dependent) in control rats was reversed to paired-pulse facilitation (PPF) in BPA-rats. Perfusion of slices obtained from BPA-rats with the GABA(A) receptor (GABA(A)R) agonist muscimol blocked the multispike responses and LTP, and recovered PPI. By contrast, the dopamine D1 receptor antagonist SCH23390 abolished LTP and attenuated the increased amplitude of 1st-PS in BPA-rats. Conversely, blockade of GABA(A)R by bicuculline could produce the multispike responses and PPF in BLA in control rats. Furthermore, in BLA the infusion of SCH23390, muscimol or the NMDAR blocker MK801 ameliorated the hyperactivity and improved the deficits in attention. These findings suggest that the perinatal exposure to BPA causes GABAergic disinhibition and dopaminergic enhancement, leading to an abnormal cortical-BLA synaptic transmission and plasticity, which may be responsible for the hyperactivity and attention-deficit in BPA-rats. This article is part of a Special Issue entitled 'Synaptic Plasticity & Interneurons'.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants, Occupational / adverse effects*
  • Air Pollutants, Occupational / pharmacology
  • Amygdala / drug effects*
  • Amygdala / physiology*
  • Animals
  • Attention Deficit Disorder with Hyperactivity / chemically induced*
  • Attention Deficit Disorder with Hyperactivity / pathology
  • Benzazepines / pharmacology
  • Benzhydryl Compounds
  • Bicuculline / pharmacology
  • Disease Models, Animal
  • Dizocilpine Maleate / pharmacology
  • Dopamine Antagonists / pharmacology
  • Female
  • GABA-A Receptor Agonists / pharmacology
  • GABA-A Receptor Antagonists / pharmacology
  • Glutamate Decarboxylase / analysis
  • Long-Term Potentiation / drug effects
  • Long-Term Potentiation / physiology
  • Male
  • Muscimol / pharmacology
  • Neuronal Plasticity / physiology*
  • Phenols / adverse effects*
  • Phenols / pharmacology
  • Pregnancy
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, N-Methyl-D-Aspartate / antagonists & inhibitors


  • Air Pollutants, Occupational
  • Benzazepines
  • Benzhydryl Compounds
  • Dopamine Antagonists
  • GABA-A Receptor Agonists
  • GABA-A Receptor Antagonists
  • Phenols
  • Receptors, N-Methyl-D-Aspartate
  • SCH 23390
  • Muscimol
  • Dizocilpine Maleate
  • Glutamate Decarboxylase
  • glutamate decarboxylase 1
  • bisphenol A
  • Bicuculline