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Ferraro, T. N.

Publications and source records attributed to Ferraro, T. N..

3 recordsLinked to original sources

The astrocyte Fabp7 gene regulates diurnal seizure threshold and activity-dependent gene expression in mice

Epileptic seizures are often influenced by time-of-day and changes in vigilance state, yet the molecular and cellular mechanisms underpinning these associations remain poorly understood. Astrocytes, a pivotal type of glial cell, play a critical role in modulating neuronal excitability and circadian rhythms, and they express Fatty Acid Binding Protein 7 (Fabp7), a molecule vital for sleep regulation, lipid signaling, and gene transcription. This study investigates the role of Fabp7 in determining time-of-day dependent seizure susceptibility. We assessed electroshock seizure thresholds in male C57/BL6N wild-type (WT) and Fabp7 knockout (KO) mice. Results demonstrated that, compared to WT mice, Fabp7 KO mice displayed significantly elevated general and maximal electroshock seizure thresholds (GEST and MEST) during the dark phase, but not during the light phase. To explore the impact of Fabp7 on activity-dependent gene expression during seizures, we conducted RNA sequencing (RNA-seq) on cortical and hippocampal tissues from WT and Fabp7 KO mice following MEST and SHAM procedures during the dark period. While immediate early genes (IEGs) showed considerable differential expression between WT-MEST and WT-SHAM, this expression was absent in Fabp7 KO-MEST compared to Fabp7 KO-SHAM. Gene ontology analyses revealed significant overlaps between the WT-MEST:WT-SHAM and Fabp7 KO-SHAM:WT-SHAM comparisons, indicating that the basal mRNA expression profiles in Fabp7 KO brains resemble those of WT brains in a post-ictal state. Collectively, these findings suggest that Fabp7 is a key regulator of time-of-day dependent neural excitability and that astrocyte-mediated signaling pathways involving Fabp7 interact with neuronal activity to influence gene expression in response to seizures. Significance StatementChanges in sleep/wake state and/or circadian time-of-day are thought to influence neural excitability, which may confer seizure susceptibility. Here we describe a role for astrocytic Fabp7 in regulating nocturnal seizure threshold and gene expression associated with differences in seizure susceptibility, introducing an astrocyte factor that may represent a novel antiepileptic target for drug development.

neuroscience↗

Single-nuclei transcriptomics of schizophrenia prefrontal cortex primarily implicates neuronal subtypes

Transcriptomic studies of bulk neural tissue homogenates from persons with schizophrenia and controls have identified differentially expressed genes in multiple brain regions. However, the brains heterogeneous nature prevents identification of relevant cell types. This study analyzed single-nuclei transcriptomics of ~275,000 nuclei from frozen human postmortem dorsolateral prefrontal cortex samples from males with schizophrenia (n = 12) and controls (n = 14). 4,766 differential expression events were identified in 2,994 unique genes in 16 of 20 transcriptomically-distinct cell populations. ~96% of differentially expressed genes occurred in five neuronal cell types, and differentially expressed genes were enriched for genes associated with schizophrenia and bipolar GWAS loci. Downstream analyses identified cluster-specific enriched gene ontologies, KEGG pathways, and canonical pathways. Additionally, microRNAs and transcription factors with overrepresented neuronal cell type-specific targets were identified. These results expand our knowledge of disrupted gene expression in specific cell types and permit new insight into the pathophysiology of schizophrenia.

neuroscience↗

Colocalization of MOR1 and GAD67 in Mouse Nucleus Accumbens

Current understanding of the rewarding and addictive effects of opioids involves mu-opioid receptor (MOR) binding within the nucleus accumbens (NAcc), a region of the ventral striatum. GABAergic neurotransmission in the NAcc potentiates the rewarding response to opioids, and in fact, drugs that stimulate GABAergic activity are also addictive, a phenomenon mediated in part by endogenous opioids. However, the neuroanatomical relationship between opioid and GABA systems is still unclear, and further study of the interaction between these neurotransmitter systems in the reward pathway is warranted. We report evidence supporting the direct interaction between GABAergic and opioidergic neurotransmitter systems within the mouse NAcc. Male and female FVB/NJ mice (12-16 months of age) were euthanized via carbon dioxide inhalation and brains processed for histology and immunohistochemistry (IHC). Coronal cryosections (10-12 um in thickness) were taken through the NAcc at the level of the anterior commissure. A mouse monoclonal antibody against GAD67, an enzyme catalyzing GABA production, was used in conjunction with an anti-mouse rhodamine red-X-labeled secondary antibody to identify GABAergic neurons in the NAcc. Alternating sections were stained for MOR using a fluorescein isothiocyanate (FITC)-conjugated rabbit polyclonal anti-MOR1 antibody. DAPI (4',6-diamidino-2-phenylindole) was used to counterstain the nuclei. As expected, fluorescence microscopy results show that GAD67 staining is localized predominately in the neuronal cytoplasm, with approximately 40% of the population staining. The MOR1-FITC stain showed localization within the cytoplasm and plasma membrane as expected, however, there was also significant staining in the nuclear membrane and neuronal nucleus. MOR1-FITC was present in approximately 35% of the neuronal population. In separate experiments, we used double-immunostaining to study the co-expression of MOR1 and GAD67 within the same NAcc neurons. A similar localization pattern was detected with a small subset, approximately 2%, of neurons expressing both labels. There are few published reports of GAD67 and MOR1 co-expression within neurons of the NAcc. Previous studies of MOR expression show the receptor to be localized to the plasma membrane and, to a smaller degree, intracellularly. Here we found the MOR1 staining to be predominantly in the nucleus and nuclear membrane, with minimal expression on the plasma membrane. Further studies are in progress to validate the nuclear expression of MOR in GABAergic NAcc neurons. Results of the study suggest that a subset of mouse NAcc neurons express both MOR1 and GAD67, providing a direct intracellular link between opioid and GABAergic systems in the reward pathway. Preliminary intranuclear localization of MOR suggests a novel signaling pathway that may be important in fully elucidating neurobiological mechanisms underlying behaviors related to reward and addiction.

neuroscience↗