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Siddiqi MT, Podder D, Pahng AR, Athanason AC, Nadav T, Cates-Gatto C, Kreifeldt M, Contet C, Roberts AJ, Edwards S, Roberto M, Varodayan FP. Prefrontal cortex glutamatergic adaptations in a mouse model of alcohol use disorder. ADDICTION NEUROSCIENCE 2023; 9:100137. [PMID: 38152067 PMCID: PMC10752437 DOI: 10.1016/j.addicn.2023.100137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
Alcohol use disorder (AUD) produces cognitive deficits, indicating a shift in prefrontal cortex (PFC) function. PFC glutamate neurotransmission is mostly mediated by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type ionotropic receptors (AMPARs); however preclinical studies have mostly focused on other receptor subtypes. Here we examined the impact of early withdrawal from chronic ethanol on AMPAR function in the mouse medial PFC (mPFC). Dependent male C57BL/6J mice were generated using the chronic intermittent ethanol vapor-two bottle choice (CIE-2BC) paradigm. Non-dependent mice had access to water and ethanol bottles but did not receive ethanol vapor. Naïve mice had no ethanol exposure. We used patch-clamp electrophysiology to measure glutamate neurotransmission in layer 2/3 prelimbic mPFC pyramidal neurons. Since AMPAR function can be impacted by subunit composition or plasticity-related proteins, we probed their mPFC expression levels. Dependent mice had higher spontaneous excitatory postsynaptic current (sEPSC) amplitude and kinetics compared to the Naïve/Non-dependent mice. These effects were seen during intoxication and after 3-8 days withdrawal, and were action potential-independent, suggesting direct enhancement of AMPAR function. Surprisingly, 3 days withdrawal decreased expression of genes encoding AMPAR subunits (Gria1/2) and synaptic plasticity proteins (Dlg4 and Grip1) in Dependent mice. Further analysis within the Dependent group revealed a negative correlation between Gria1 mRNA levels and ethanol intake. Collectively, these data establish a role for mPFC AMPAR adaptations in the glutamatergic dysfunction associated with ethanol dependence. Future studies on the underlying AMPAR plasticity mechanisms that promote alcohol reinforcement, seeking, drinking and relapse behavior may help identify new targets for AUD treatment.
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Affiliation(s)
- Mahum T. Siddiqi
- Developmental Exposure Alcohol Research Center and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, NY, 13902, USA
| | - Dhruba Podder
- Developmental Exposure Alcohol Research Center and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, NY, 13902, USA
| | - Amanda R. Pahng
- Department of Physiology, Louisiana State University Health Sciences Center, 533 Bolivar Street, New Orleans, LA, 70112, USA
- Southeast Louisiana Veterans Health Care System, 2400 Canal Street, 11F, New Orleans, LA, 70119, USA
| | - Alexandria C. Athanason
- Developmental Exposure Alcohol Research Center and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, NY, 13902, USA
| | - Tali Nadav
- Animal Models Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Chelsea Cates-Gatto
- Animal Models Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Max Kreifeldt
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Candice Contet
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Amanda J. Roberts
- Animal Models Core Facility, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Scott Edwards
- Department of Physiology, Louisiana State University Health Sciences Center, 533 Bolivar Street, New Orleans, LA, 70112, USA
| | - Marisa Roberto
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Florence P. Varodayan
- Developmental Exposure Alcohol Research Center and Behavioral Neuroscience Program, Department of Psychology, Binghamton University-SUNY, 4400 Vestal Parkway East, Binghamton, NY, 13902, USA
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
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Gruol DL, Calderon D, Huitron-Resendiz S, Cates-Gatto C, Roberts AJ. Impact of Elevated Brain IL-6 in Transgenic Mice on the Behavioral and Neurochemical Consequences of Chronic Alcohol Exposure. Cells 2023; 12:2306. [PMID: 37759527 PMCID: PMC10527024 DOI: 10.3390/cells12182306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
Alcohol consumption activates the neuroimmune system of the brain, a system in which brain astrocytes and microglia play dominant roles. These glial cells normally produce low levels of neuroimmune factors, which are important signaling factors and regulators of brain function. Alcohol activation of the neuroimmune system is known to dysregulate the production of neuroimmune factors, such as the cytokine IL-6, thereby changing the neuroimmune status of the brain, which could impact the actions of alcohol. The consequences of neuroimmune-alcohol interactions are not fully known. In the current studies we investigated this issue in transgenic (TG) mice with altered neuroimmune status relative to IL-6. The TG mice express elevated levels of astrocyte-produced IL-6, a condition known to occur with alcohol exposure. Standard behavioral tests of alcohol drinking and negative affect/emotionality were carried out in homozygous and heterozygous TG mice and control mice to assess the impact of neuroimmune status on the actions of chronic intermittent alcohol (ethanol) (CIE) exposure on these behaviors. The expressions of signal transduction and synaptic proteins were also assessed by Western blot to identify the impact of alcohol-neuroimmune interactions on brain neurochemistry. The results from these studies show that neuroimmune status with respect to IL-6 significantly impacts the effects of alcohol on multiple levels.
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Affiliation(s)
- Donna L. Gruol
- Neuroscience Department, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Delilah Calderon
- Neuroscience Department, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | - Chelsea Cates-Gatto
- Animal Models Core Facility, The Scripps Research Institute, La Jolla, CA 92037, USA (A.J.R.)
| | - Amanda J. Roberts
- Animal Models Core Facility, The Scripps Research Institute, La Jolla, CA 92037, USA (A.J.R.)
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