Prenatal Exposure to Ethanol Alters Synaptic Activity in Layer V/VI Pyramidal Neurons of the Somatosensory Cortex

Cereb Cortex. 2020 Mar 14;30(3):1735-1751. doi: 10.1093/cercor/bhz199.


Fetal alcohol spectrum disorder (FASD) encompasses a range of cognitive and behavioral deficits, with aberrances in the function of cerebral cortical pyramidal neurons implicated in its pathology. However, the mechanisms underlying these aberrances, including whether they persist well beyond ethanol exposure in utero, remain to be explored. We addressed these issues by employing a mouse model of FASD in which pregnant mice were exposed to binge-type ethanol from embryonic day 13.5 through 16.5. In both male and female offspring (postnatal day 28-32), whole-cell patch clamp recording of layer V/VI somatosensory cortex pyramidal neurons revealed increases in the frequency of excitatory and inhibitory postsynaptic currents. Furthermore, expressing channelrhodopsin in either GABAergic interneurons (Nkx2.1Cre-Ai32) or glutamatergic pyramidal neurons (Emx1IRES Cre-Ai32) revealed a shift in optically evoked paired-pulse ratio. These findings are consistent with an excitatory-inhibitory imbalance with prenatal ethanol exposure due to diminished inhibitory but enhanced excitatory synaptic strength. Prenatal ethanol exposure also altered the density and morphology of spines along the apical dendrites of pyramidal neurons. Thus, while both presynaptic and postsynaptic mechanisms are affected following prenatal exposure to ethanol, there is a prominent presynaptic component that contributes to altered inhibitory and excitatory synaptic transmission in the somatosensory cortex.

Keywords: FASD; electrophysiology; gestational binge-ethanol; neurotransmission; optogenetics.

Publication types

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

MeSH terms

  • Animals
  • Dendrites / drug effects
  • Dendrites / physiology
  • Disease Models, Animal
  • Ethanol / pharmacology*
  • Female
  • Inhibitory Postsynaptic Potentials / drug effects
  • Mice
  • Prefrontal Cortex / drug effects*
  • Prefrontal Cortex / physiology
  • Pregnancy
  • Prenatal Exposure Delayed Effects / physiopathology
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / physiology
  • Somatosensory Cortex / drug effects*
  • Somatosensory Cortex / physiopathology
  • Synaptic Transmission / drug effects*
  • Synaptic Transmission / physiology


  • Ethanol