Probes for INS

The central amygdala (CeA) contains a diverse population of cells, including multiple subtypes of GABAergic neurons, along with glia and epithelial cells. Specific CeA cell types have been shown to affect alcohol consumption in animal models of dependence and may be involved in negative affect during alcohol withdrawal. We used single-nuclei RNA sequencing to determine cell-type specificity of differential gene expression in the CeA induced by alcohol withdrawal. Cells within the CeA were classified using unbiased clustering analyses and identified based on the expression of known marker genes. Differential gene expression analysis was performed on each identified CeA cell-type. It revealed differential gene expression in astrocytes and GABAergic neurons associated with alcohol withdrawal. GABAergic neurons were further subclassified into 13 clusters of cells. Analyzing transcriptomic responses in these subclusters revealed that alcohol exposure induced multiple differentially expressed genes in one subtype of CeA GABAergic neurons, the protein kinase C delta (PKCδ) expressing neurons. These results suggest that PKCδ neurons in the CeA may be uniquely sensitive to the effects of alcohol exposure and identify a novel population of cells in CeA associated with alcohol withdrawal.

Fibroblast growth factor (FGF) signaling plays several important roles in the development of the central nervous system. During the mid-gestation stage, FGF receptors (FGFRs) are expressed in the ventricular zone of the telencephalon and regulate the proliferation and neuronal differentiation of radial glial cells (RGCs). Inhibition of FGFR signaling at this stage results in abnormal brain formation, particularly loss of FGFR1 signaling causes hypoplasia of the olfactory bulb (OB). However, how FGFR1 signaling regulates OB formation is not fully understood. In this study, we inhibited FGFR1 signaling specifically in the anterior telencephalon, where OBs develop, and examined its effects on the development of RGCs in the OB (OB RGCs) and OB formation. The results suggest that inhibition of FGFR1 signaling causes a shift in the state of OB RGCs from proliferation to neuronal differentiation, resulting in an insufficient number of OB projection neurons. Furthermore, activation of Notch signaling, which maintains the self-renewal state of OB RGCs, partially rescued the early abnormal OB formation caused by inhibition of FGFR1 signaling. In contrast, inhibition of FGFR1 signaling in lateral ganglionic eminence did not affect the production of OB interneurons or OB formation. Moreover, the early abnormal OB formation induced by inhibition of FGFR1 signaling could be rescued by overactivation of Notch signaling, which maintains the proliferative state of radial glial cells. These results suggest that FGFR1 signaling regulates normal OB formation by controlling OB RGCs to produce a normal number of OB projection neurons.