Increased Synaptic Strength and mGlu_2/3 Receptor Plasticity on Mouse Prefrontal Cortex Intratelencephalic Pyramidal...

Area of Science:

• Neuroscience
• Neurobiology
• Addiction Research

Background:

• The medial prefrontal cortex (mPFC) plays a key role in regulating craving and alcohol seeking in alcohol use disorder (AUD).
• Voluntary ethanol (EtOH) intake can lead to maladaptive changes in mPFC function, but synaptic adaptations within this region are not consistently detected in animal models.
• Pyramidal cells in the mPFC project to various brain regions involved in AUD, including telencephalic (IT) and extra-telencephalic (ET) targets.

Purpose of the Study:

• To investigate synaptic adaptations in specific mPFC pyramidal cell subtypes after chronic intermittent ethanol (EtOH) exposure.
• To differentiate between ET (type A) and IT (type B) pyramidal neurons using the hyperpolarization sag ratio.
• To identify potential therapeutic targets for AUD by examining EtOH-induced changes in mPFC neurocircuits.

Main Methods:

• Recorded from deep-layer prelimbic mPFC pyramidal cells in mice following 4-5 weeks of intermittent access (IA) to EtOH.
• Classified pyramidal cells into ET (type A) and IT (type B) subtypes using the hyperpolarization sag ratio.
• Assessed membrane properties and excitatory postsynaptic strength in response to IA EtOH exposure.

Main Results:

• Intermittent access to EtOH did not alter general membrane properties of mPFC neurons.
• Excitatory postsynaptic strength was selectively enhanced in IT type B neurons from IA EtOH mice.
• This enhanced excitatory drive correlated with increased mGlu2/3 receptor plasticity in IT type B neurons.

Conclusions:

• Voluntary ethanol consumption induces specific neurocircuit alterations in the mPFC.
• Enhanced excitatory drive and mGlu2/3 receptor plasticity in IT type B neurons represent key adaptations to chronic EtOH exposure.
• Potentiating mGlu2 and/or mGlu3 receptor function may offer a novel therapeutic strategy for AUD.