Biology subjects

Vazey, E.

Publications and source records attributed to Vazey, E..

4 recordsLinked to original sources

bioRxiv2025

Impact of chronic alcohol and stress on mid-life cognition and locus coeruleus integrity

BackgroundExcessive alcohol consumption and stress are associated with structural and functional alterations in the brain and impaired cognition. However, the persistence of long-term neural impacts after alcohol and stress are less understood. This study investigated midlife cognition and neuropathological changes following a history of alcohol and stress exposure. MethodsC57BL/6J mice acclimated to ethanol drinking (15% v/v) before exposure to four cycles of alternating chronic intermittent ethanol (CIE) vapor exposure and repeated forced swim stress (FSS), with control groups exposed to air and no stress (AIR/NS). After three months of abstinence, mice were evaluated at midlife (11 months old) on volitional drinking and a final CIE/FSS challenge for stress induced drinking. Spatial learning and cognitive flexibility were assessed using the Barnes maze before brains were collected to evaluate locus coeruleus integrity at 12 months old. ResultsCIE/FSS increased volitional alcohol intake, and this drinking phenotype persisted through to midlife despite extended abstinence. CIE/FSS mice showed intact spatial learning but impaired flexibility in the Barnes maze reversal phase. Flexibility impairments were driven by decreased time in the target quadrant and increased errors during the reversal test compared to AIR/NS. Furthermore, CIE/FSS mice showed pathological measures of reduced locus coeruleus integrity common to dementia related disorders, including elevated markers of oxidative stress, apoptosis and reduced autoinhibitory function. ConclusionsOur findings highlight the long-lasting impact of alcohol and stress exposure on cognition, with flexibility impairments persisting into midlife. In addition to cognitive changes, alcohol and stress history produced pathological changes in the locus coeruleus, an area known to mediate cognitive flexibility via its forebrain projections. Together, these results give an insight into the long-lasting impacts of chronic alcohol and stress and how they may accelerate age-related cognitive decline.

neuroscience↗

bioRxiv2023

A paradigm for ethanol consumption in head-fixed mice during prefrontal cortical two-photon calcium imaging

The prefrontal cortex (PFC) is a hub for higher-level cognitive behaviors and is a key target for neuroadaptations in alcohol use disorders. Preclinical models of ethanol consumption are instrumental for understanding how acute and repeated drinking affects PFC structure and function. Recent advances in genetically encoded sensors of neuronal activity and neuromodulator release combined with functional microscopy (multiphoton and one-photon widefield imaging) allow multimodal in-vivo PFC recordings at subcellular and cellular scales. While these methods could enable a deeper understanding of the relationship between alcohol and PFC function/dysfunction, they require animals to be head-fixed. Here, we present a method in mice for binge-like ethanol consumption during head-fixation. Male and female mice were first acclimated to ethanol by providing home cage access to 20% ethanol (v/v) for 4 or 8 days. After home cage drinking, mice consumed ethanol from a lick spout during head-fixation. We used two-photon calcium imaging during the head-fixed drinking paradigm to record from a large population of PFC neurons (>1000) to explore how acute ethanol affects their activity. Drinking modulated activity rates in a subset of neurons on slow (minutes) and fast (seconds) time scales but the majority of neurons were unaffected. Moreover, ethanol intake did not significantly affect network level interactions in the PFC as assessed through inter-neuronal pairwise correlations. By establishing a method for binge-like drinking in head-fixed mice, we lay the groundwork for leveraging advanced microscopy technologies to study alcohol-induced neuroadaptations in PFC and other brain circuits. HighlightsO_LIC57BL/6J mice voluntarily consume ethanol to binge-like levels during head-fixation, with females consuming more ethanol than males. C_LIO_LIMice show differences in frontloading and licking behavior for head-fixed ethanol and sucrose consumption. C_LIO_LIHead-fixed paradigm enables two-photon calcium imaging in the anterior cingulate cortex subdivision of the prefrontal cortex. C_LIO_LIAcute ethanol increases and decreases single neuron activity at fast (seconds) and slow (minutes) time scales but does not alter pairwise correlations between neurons. C_LI

neuroscience↗

bioRxiv2021

Individual differences in behavioral flexibility predict future volitional ethanol consumption in mice

Cognitive control is key to regulating alcohol intake and preventing relapse. Behavioral inflexibility can prevent adaptive strategies such as mindfulness or other relapse-prevention behaviors. In a mouse model we investigated whether individual variability in behavioral flexibility (using attentional set-shifting task; ASST) predicts future alcohol intake. Adult male and female C57BL/6J mice were subjected to ASST using a bowl digging paradigm where mice identify a baited bowl based on compound odor and textural cues. This was completed prior to any alcohol exposure. Individual performance across mice varied within the group. We integrated several metrics, specifically ASST stage completed, trials to completion and errors performed to produce an individual performance index measure of behavioral flexibility. After, ASST mice were trained to drink ethanol (15%, v/v, 1hr/day) for 3-4 weeks until intake stabilized. Using this prospective approach, we identified an inverse relationship between behavioral flexibility and drinking - less flexible mice had a propensity to consume more alcohol. Similar relationships have been identified previously in non-human primates and rats. Our results show that the relationship between alcohol and cognitive flexibility is a robust trait that is conserved across species and can be used in mice to study neural substrates underlying these behaviors. HIGHLIGHTS- ASST can be used to examine individual differences in cognitive function in mice - Behavioral inflexibility is related to future higher alcohol consumption - Executive function can be used as a predictive risk factor for alcohol intake - This relationship in mice supports previous findings across species

neuroscience↗

bioRxiv2021

Voluntary alcohol consumption disrupts coupling of prefrontal cortical activity to arousal

Alcohol use disorder (AUD) exacts a major personal, societal, and economic toll. Top-down control from the prefrontal cortex (PFC), a critical hub for decision making, executive, and other cognitive functions, is key for the regulation of alcohol consumption. Arousal exerts profound effects on cortical processing, allowing it to potentially modulate PFC functions relevant for alcohol consumption and AUD. Despite this, it is unclear whether and how arousal-mediated modulation of PFC circuits relates to voluntary alcohol drinking behaviors. Two-photon microscopy is ideally suited for dissecting the neural circuit mechanisms underlying the effect of alcohol on intact circuits in behaving animals. We addressed a major limitation of this technology by developing a novel behavioral paradigm for voluntary drinking in head-fixed mice. We recorded responses of layer 2/3 excitatory neurons in the anterior cingulate cortex (ACC) subdivision of the PFC as mice voluntarily consumed ethanol, along with video recording of the pupil to track momentary fluctuations in arousal. Ethanol consumption bidirectionally modified the activity of subsets of ACC neurons, both at slow (minutes) and fast (sub-second) time scales. Remarkably, we found that the coupling of arousal to ACC activity before drinking was associated with subsequent ethanol engagement behavior. In turn, ethanol consumption modulated neuronal-arousal coupling. Together, our results suggest neuronal-arousal coupling as a key biomarker for alcohol drinking and lays the groundwork for future studies to dissect the therapeutic potential of this process for AUD and other substance use disorders.

neuroscience↗