Biology subjects

Lasek, A. W.

Publications and source records attributed to Lasek, A. W..

6 recordsLinked to original sources

bioRxiv2026

Astrocyte-expressed STAT3 regulates glutamate homeostasis and binge ethanol drinking in mice

Astrocytes play an important role in neuronal health. A critical function of astrocytes is to clear excess extracellular glutamate and prevent excitotoxicity. STAT3 is a transcription factor that promotes astrocyte development and astrocyte reactivity in neurodegenerative diseases and following central nervous system injury. To determine the innate molecular and behavioral functions of adult astrocyte-expressed STAT3 in a non-pathological state, we created conditional Stat3 astrocyte knockout mice (Stat3 aKO) using Stat3flox and the tamoxifen-activated Cre line, Aldh1l1-Cre/ERT2. We measured transcript levels of Gfap, a known STAT3 target gene, and glutamate transporter genes in the medial prefrontal cortex (PFC) of Stat3 aKO. Gfap, Slc1a2 and Slc17a8 transcripts were decreased in the PFC of Stat3 aKO of both sexes. GLT-1 protein, encoded by Slc1a2, was also reduced in the PFC of male Stat3 aKO. We recorded spontaneous excitatory post-synaptic currents (sEPSCs) in male Stat3 aKO and control prelimbic pyramidal neurons and found increased sEPSC amplitude, consistent with a hyper-glutamatergic state due to impaired glutamate clearance. To determine the behavioral consequences of STAT3 depletion in astrocytes, Stat3 aKO were tested for locomotor activity, anxiety-like behavior and binge ethanol consumption, behaviors linked to dysregulation of glutamate homeostasis. Stat3 aKO mice did not differ in locomotor activity or anxiety-like behavior; however, male Stat3 aKO mice consumed significantly less ethanol than controls. These results indicate that STAT3 in adult astrocytes is crucial for maintaining glutamate transporter levels in the adult brain and that astrocytic STAT3 promotes ethanol consumption in male mice. Main pointsO_LIGfap, Slc1a2 and Slc17a8 expression are lower in the cortex of Stat3 astrocyte knockout mice (Stat3 aKO) C_LIO_LIGLT-1 protein is decreased and glutamate neurotransmission is elevated in the cortex of male Stat3 aKO C_LIO_LIMale Stat3 aKO consume less ethanol C_LI

neuroscience↗

bioRxiv2023

Sexually Dimorphic Role for Insular Perineuronal Nets in Aversion-Resistant Ethanol Consumption

Compulsive alcohol drinking is a key symptom of alcohol use disorder (AUD) that is particularly resistant to treatment. An understanding of the biological factors that underly compulsive drinking will allow for the development of new therapeutic targets for AUD. One animal model of compulsive alcohol drinking involves the addition of bitter-tasting quinine to an ethanol solution and measuring the willingness of the animal to consume ethanol despite the aversive taste. Previous studies have demonstrated that this type of aversion-resistant drinking is modulated in the insular cortex of male mice by specialized condensed extracellular matrix known as perineuronal nets (PNNs), which form a lattice-like structure around parvalbumin-expressing neurons in the cortex. Several laboratories have shown that female mice exhibit higher levels of aversion-resistant ethanol intake but the role of PNNs in females in this behavior has not been examined. Here we compared PNNs in the insula of male and female mice and determined if disrupting PNNs in female mice would alter aversion-resistant ethanol intake. PNNs were visualized in the insula by fluorescent labeling with Wisteria floribunda agglutinin (WFA) and disrupted in the insula by microinjecting chondroitinase ABC, an enzyme that digests the chondroitin sulfate glycosaminoglycan component of PNNs. Mice were tested for aversion-resistant ethanol consumption by the addition of sequentially increasing concentrations of quinine to the ethanol in a two-bottle choice drinking in the dark procedure. PNN staining intensity was higher in the insula of female compared to male mice, suggesting that PNNs in females might contribute to elevated aversion-resistant drinking. However, disruption of PNNs had limited effect on aversion-resistant drinking in females. In addition, activation of the insula during aversion-resistant drinking, as measured by c-fos immunohistochemistry, was lower in female mice than in males. Taken together, these results suggest that neural mechanisms underlying aversion-resistant ethanol consumption differ in males and females.

animal behavior and cognition↗

bioRxiv2022

Estrogen signaling in the dorsal raphe regulates binge-like drinking in mice

The ovarian hormone estrogens promote binge alcohol drinking and contribute to sex differences in alcohol use disorder. However, the mechanisms for estrogen-induced binge drinking are largely unknown. This study aims to test if estrogens act on 5-hydroxytryptamine neurons in the dorsal raphe nucleus (5-HTDRN) to promote binge drinking. We used the drinking in the dark (DID) behavioral test in mice to mimic binge drinking in humans. We found that female mice drank more alcohol than male mice in chronic DID tests. This sex difference was associated with distinct alterations in mRNA expression of estrogen receptor (ER) and 5-HT-related genes in the DRN, suggesting a potential role of estrogen/ERs/5-HT signaling in binge alcohol drinking. In supporting this view, 5-HTDRN neurons from naive male mice had lower baseline neuronal firing activity but higher sensitivity to alcohol-induced excitation compared to 5-HTDRN neurons from naive female mice. Notably, this higher sensitivity was blunted by 17{beta}-estradiol treatment in males, indicating an estrogen-dependent mechanism. We further showed that both ER and ER{beta} are expressed in 5-HTDRN neurons, whereas ER agonist propyl pyrazole triol (PPT) depolarizes 5-HTDRN neurons and ER{beta} agonist diarylpropionitrile (DPN) hyperpolarizes 5-HTDRN neurons. Notably, both PPT and DPN treatments blocked the stimulatory effects of alcohol on 5-HTDRN neurons in males, despite the fact that they have antagonistic effects on the activity dynamics of 5-HTDRN neurons. These results suggest that ERs inhibitory effects on ethanol-induced burst firing of 5-HTDRN neurons may contribute to higher levels of binge drinking in females. Consistently, chemogenetic activation of ER- or ER{beta}-expressing neurons in the DRN reduced binge alcohol drinking. These results support a model in which estrogens act on ER/{beta} to prevent alcohol-induced activation of 5-HTDRN neurons, which in return leads to higher binge alcohol drinking.

neuroscience↗

bioRxiv2020

Estradiol enhances ethanol stimulation of ventral tegmental area dopamine neuron firing without limiting ethanol inhibition onto those neurons

Females can progress to alcohol and other substance use disorders more quickly than males. The ovarian hormone 17{beta}-estradiol (E2) contributes to sex differences observed in drug use and abuse and may be a principal driver of these differences. However, it is not entirely clear how E2 acts to affect processing of ethanol reward, and several brain regions and mechanisms are implicated. We sought to clarify the role of E2 in modulating the response of ventral tegmental area dopamine neurons to ethanol. To this end, we recorded spontaneous action potentials and inhibitory post synaptic currents from dopaminergic neurons in acute horizontal brain slices from ovariectomized (OVX) dopamine neuron reporter mice (Pitx3-eGFP) treated with either vehicle (VEH) or E2. On the basis of prior work, we hypothesized that E2 administration would cause dopamine cells from OVX+E2 animals to show a more substantial ethanol-induced increase in firing rate compared to control animals. Our data confirmed that ethanol stimulation of the firing rate of dopamine neurons from OVX+E2 mice was greater than that of OVX+VEH animals. Further, we hypothesized that the firing rate increase would be accompanied by a concomitant decrease in ethanol stimulated inhibition onto those same neurons. We found that although ethanol caused the expected increase in GABAA receptor-mediated synaptic inhibition in both groups, there was no difference in this response between OVX+E2 and OVX+VEH animals. Our findings lend additional support for the ability of E2 to enhance ventral tegmental area dopamine neuron responses to ethanol and suggest that this effect is not mediated by an E2-elicited suppression of synaptic inhibition.

neuroscience↗

bioRxiv2019

Estrogen Receptor α Regulates Ethanol Excitation of Ventral Tegmental Area Neurons and Binge Drinking in Female Mice

Elevations in estrogen (17{beta}-estradiol, E2) are associated with increased alcohol drinking by women and experimentally in rodents. E2 alters the activity of the dopamine system, including the ventral tegmental area (VTA) and its projection targets, which plays an important role in binge drinking. A previous study demonstrated that during high E2 states, VTA dopamine neurons in female mice are more sensitive to ethanol excitation. However, the mechanisms responsible for the ability of E2 to enhance ethanol sensitivity of VTA dopamine neurons have not been investigated. In this study, we used selective agonists and antagonists to examine the role of estrogen receptor subtypes (ER and ER{beta}) in regulating the ethanol sensitivity of VTA dopamine neurons and found that ER promotes the enhanced ethanol response of VTA dopamine neurons. We also demonstrated that the E2-induced increase in ethanol excitation requires the activity of the metabotropic glutamate receptor, mGluR1, which is known to couple with ER at the plasma membrane. To investigate the behavioral relevance of these findings, we administered lentivirus expressing short hairpin RNAs targeting either ER or ER{beta} into the VTA and found that knockdown of each receptor in the VTA reduced binge-like ethanol drinking in female, but not male, mice. Reducing ER in the VTA had a more dramatic effect on binge-like drinking than reducing ER{beta}, consistent with the ability of ER to alter ethanol sensitivity of dopamine neurons. These results provide important insight into sex-specific mechanisms that drive excessive alcohol drinking.\n\nSignificance StatementEstrogen has potent effects on the dopamine system and increases the vulnerability of females to develop addiction to substances such as cocaine and alcohol. We investigated the mechanisms by which estrogen increases the response of dopamine neurons in the ventral tegmental area to ethanol. We found that activation of the estrogen receptor, ER, increased the ethanol-induced excitation of dopamine neurons and that this required the metabotropic glutamate receptor mGluR1. We also demonstrated that estrogen receptors in the ventral tegmental area regulate binge-like alcohol drinking by female, but not male, mice. The influence of estrogen receptors on binge drinking in female mice suggests that treatments for alcohol use disorder in women may need to account for this sex difference.

neuroscience↗

bioRxiv2018

Perineuronal Nets in the Insula Regulate Aversion-Resistant Alcohol Drinking

One of the most pernicious characteristics of alcohol use disorder is the compulsion to drink despite negative consequences. The insular cortex (insula) controls decision-making under conditions of risk or conflict and regulates maladaptive behaviors in the context of addiction. Cortical activity is tightly controlled by fast-spiking inhibitory interneurons that are often enclosed by specialized extracellular matrix structures known as perineuronal nets, which regulate neuronal excitability and plasticity. Using a mouse model of compulsive drinking in which alcohol was adulterated with the bitter tastant quinine, we demonstrate that disrupting perineuronal nets in the insula rendered mice more sensitive to quinine-adulterated alcohol. Activation of the insula, as measured by c-fos expression, occurred during aversion-resistant drinking and was further enhanced by elimination of perineuronal nets. These results provide fundamental insight into neuroanatomical and cellular mechanisms that control compulsive drinking.

neuroscience↗