Altered Activity of Lateral Orbitofrontal Cortex Neurons in Mice following Chronic Intermittent Ethanol Exposure

Area of Science:

• Neuroscience
• Behavioral Science
• Addiction Research

Background:

• The lateral orbitofrontal cortex (LOFC) is crucial for decision-making and processing reward value.
• Damage to the LOFC impairs behavioral flexibility and reward-related decision-making.
• Chronic intermittent ethanol (CIE) exposure is known to disrupt OFC-dependent behaviors.

Purpose of the Study:

• To investigate how CIE exposure alters LOFC neuronal activity during alcohol consumption.
• To examine LOFC neural responses when the reward value of ethanol is modified by tastants.
• To test the hypothesis that CIE exposure leads to LOFC hyperexcitability during alcohol drinking.

Main Methods:

• Utilized GCaMP6f fiber photometry to monitor LOFC neuronal activity in mice.
• Administered acute ethanol injections to naive mice.
• Trained mice in operant ethanol self-administration and exposed them to CIE or air controls, followed by recording LOFC activity during consumption of alcohol, alcohol+quinine, or alcohol+sucrose solutions.

Main Results:

• Acute ethanol decreased LOFC neuronal firing frequency in naive mice.
• CIE-exposed mice showed significantly enhanced ethanol self-administration and consumption, resistant to aversion.
• LOFC neurons exhibited hyperexcitability and altered activity patterns in CIE-exposed mice, varying with the ethanol solution consumed.

Conclusions:

• CIE exposure induces significant alterations in LOFC neuronal activity and function.
• LOFC hyperexcitability and aversion-resistant ethanol seeking are key consequences of CIE exposure.
• These findings highlight the role of the LOFC in alcohol-related behavioral changes induced by chronic ethanol exposure.