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Pagano, R.

Publications and source records attributed to Pagano, R..

5 recordsLinked to original sources

Estrogen receptor alpha regulates alcohol craving in females: convergent evidence from mouse models and human genetics

Alcohol craving and consumption fluctuate across the reproductive cycle in females with alcohol use disorder (AUD), suggesting that estrogen signaling contributes to disease vulnerability. Here, we investigated the role of estrogen receptor alpha (ER; Esr1; ESR1) in alcohol seeking using complementary mouse and human approaches, as this receptor was previously identified as a risk factor for AUD. Female mice were characterized in an IntelliCage-based multidimensional AUD paradigm that stratifies individuals into AUD-prone and AUD-resistant phenotypes. Transcriptomic profiling of the amygdala revealed that Esr1 is a top transcription factor for differentially expressed genes in mice drinking alcohol, and the estrogen signaling pathway was deregulated specifically in AUD-prone mice. Although alcohol exposure did not alter overall Esr1/ER mRNA or protein abundance, both transcript and protein levels positively correlated with cue-induced alcohol seeking, indicating that inter-individual variation in ER signaling predicts relapse-like behavior. Causal manipulations confirmed a functional role of ER. Local knockdown of Esr1 in the basolateral amygdala reduced excitatory synaptic transmission, attenuated alcohol motivation, cue-induced seeking, and relapse drinking, and impaired cue-associated memory recall without affecting anxiety-like behavior. Similarly, ovariectomy decreased amygdala ER expression, altered synaptic protein markers, and reduced alcohol-seeking behaviors, supporting regulation by endogenous ovarian hormones. Extending these findings to humans, ESR1 gene polymorphisms (rs6902771, rs11155819 and rs6557171) were associated with the probability of alcohol binge drinking and alcohol consumption days as well as craving and loss of control in real world in a longitudinal clinical cohort, while ESR1 mRNA blood levels were increased in women with AUD diagnosis. Together, these convergent molecular, circuit, behavioral, and genetic data identify ER signaling in the amygdala as an important modulator of alcohol-seeking behavior induced by alcohol cue and relapse vulnerability, highlighting estrogen pathways as potential therapeutic targets and markers for AUD.

neuroscience↗

Loss of Brg1 promotes seizure development via GABAergic system disruption

The Brahma-related gene 1 (BRG1) encodes the catalytic subunit of the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex and plays an important role in brain development. Variants in SWI/SNF components are often found in patients with epilepsy, but it is still unclear how loss of BRG1 function contributes to seizure development. In this study, we analyzed the role of Brg1 in seizure susceptibility using zebrafish models with both pharmacological inhibition or genetic reduction of Brg1. Reduced Brg1 function caused seizure-like behavior and increased neuronal activity in larvae, while basic locomotor activity was preserved. Further analyses showed reduced expression of several GABAergic system markers. In contrast, glutamatergic markers did not show major changes. These results point to a selective impairment of inhibitory signaling. When GABA levels were increased pharmacologically, seizure-like behavior was reduced. This suggests that loss of inhibitory transmission plays an important role in the observed hyperexcitability. Unbiased omics analyses also identified changes in proteins associated with vitamin B6 binding. Treatment with active vitamin B6 reduced seizure-like behavior in larvae with reduced Brg1 function. Taken together, these results indicate that Brg1 is required for proper inhibitory neurotransmission and that partial loss of Brg1 function increases seizure susceptibility. These findings may help to better understand why mutations in chromatin remodeling genes are often associated with epilepsy and could support future studies on targeted modulation of inhibitory signaling in these conditions. Significance StatementChromatin remodeling genes are often mutated in patients with epilepsy, but it is still unclear how these mutations lead to seizures. In this study, we show that reduced function of the chromatin remodeler Brg1 affects inhibitory neurotransmission by impairing the GABAergic system. This leads to increased neuronal activity and seizure-like behavior. Our results identify the chromatin remodeler Brg1 as an important regulator of inhibitory neurotransmission and seizure susceptibility, which may be important for understanding epilepsy associated with neurodevelopmental disorders.

neuroscience↗

Projections from thalamic nucleus reuniens to hippocampal CA1 area enable context value updating

The ability to extinguish contextual fear in a changing environment is crucial for animal survival. Recent data support the role of the thalamic nucleus reuniens (RE) and its projections to the dorsal hippocampal CA1 area (RE[->]dCA1) in this process. However, it remains poorly understood how RE impacts dCA1 neurons during contextual fear extinction (CFE). Here, we reveal that the RE[->]dCA1 pathway contributes to extinction of contextual fear by affecting CFE-induced molecular remodeling of excitatory synapses. Anatomical tracing and chemogenetic manipulation in mice demonstrate that RE neurons form synapses and regulate synaptic transmission in the stratum oriens (SO) and lacunosum-moleculare (SLM) of the dCA1 area, but not in the stratum radiatum (SR). We also observe CFE-specific structural changes of excitatory synapses and expression of the synaptic scaffold protein, PSD-95, in both strata innervated by RE, but not in SR. Interestingly, only the changes in SLM are specific for the dendrites innervated by RE. To further support the role of the RE[->]dCA1 projection in CFE, we demonstrate that brief chemogenetic inhibition of the RE[->]dCA1 pathway during a CFE session persistently impairs the formation of CFE memory and CFE-induced changes of PSD-95 levels in SLM. Thus, our data indicate that RE participates in CFE by regulating CFE-induced molecular remodeling of dCA1 synapses.

animal behavior and cognition↗

Molecular fingerprints in the hippocampus of alcohol seeking during withdrawal

Alcohol use disorder (AUD) is characterized by excessive alcohol seeking and use. Here, we investigated the molecular correlates of impaired extinction of alcohol seeking using a multidimentional mouse model of AUD. We distinguished AUD-prone and AUD-resistant mice, based on the presence of [&ge;] 2 or < 2 criteria of AUD and utilized RNA sequencing to identify genes that were differentially expressed in the hippocampus and amygdala of mice meeting [&ge;] 2 or < 2 criteria, as these brain regions are implicated in alcohol motivation, seeking, consumption and the cognitive inflexibility characteristic of AUD. Our findings revealed dysregulation of the genes associated with the actin cytoskeleton, including actin binding molecule cofilin, and impaired synaptic transmission in the hippocampi of mice meeting [&ge;] 2 criteria. Overexpression of cofilin in the polymorphic layer of the dentate gyrus (PoDG) inhibited ML-DG synapses, increased motivation to seek alcohol and impaired extinction of alcohol seeking, resembling the phenotype observed in mice meeting [&ge;] 2 criteria. Overall, our study uncovers a novel mechanism linking increased hippocampal cofilin expression with the AUD phenotype. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=143 SRC="FIGDIR/small/554622v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@14b3fadorg.highwire.dtl.DTLVardef@141b1fdorg.highwire.dtl.DTLVardef@c82b8org.highwire.dtl.DTLVardef@15a16ad_HPS_FORMAT_FIGEXP M_FIG C_FIG

animal behavior and cognition↗

Contribution of PSD-95 protein to reward location memory

The molecular mechanisms involved in formation of memory are still poorly understood. We focus here on the function of post-synaptic density protein 95 (PSD-95) and its phosphorylation by CaMKII in spontaneous learning about reward location in female mice. We show that formation of reward location memory leads to downregulation of PSD-95 protein in dendritic spines of the stratum radiatum, area CA1, and selective shrinkage of dendritic spines that contain PSD-95. ShRNA-driven, long-term downregulation of PSD-95 in the area CA1 decreases precision of memory. Autophosphorylation deficient CaMKII mutant mice (CaMKII:T286A) need more time than wild-type animals to learn the location of reward. The same impairment is observed after CA1-targeted overexpression of CaMKII phosphorylation-deficient form of PSD-95 (PSD-95:S73A). In contrast to young adult mice, in aged animals reward location learning affects only spines that lack PSD-95. The frequency and size of the spines without PSD-95 are increased, while shRNA targeted to PSD-95 affects neither speed of learning nor precision of memory indicating alternative mechanisms to support successful memory formation in old mice. Altogether, our data suggest that dynamic regulation of PSD-95 expression is a mechanism that accelerates learning and improves precision of reward location memory in young mice. The function of PSD-95 in memory processes changes in aged animals.

neuroscience↗