µ-Opioid Receptor Activation Reduces Glutamate Release in the PreBötzinger Complex in Organotypic Slice Cultures.

The inspiratory rhythm generator, located in the brainstem preBötzinger complex (preBötC), is dependent on glutamatergic signaling and is affected profoundly by opioids. Here, we used organotypic slice cultures of the newborn mouse brainstem of either sex in combination with genetically encoded sensors for Ca, glutamate, and GABA to visualize Ca, glutamatergic and GABAergic signaling during spontaneous rhythm and in the presence of DAMGO. During spontaneous rhythm, the glutamate sensor SF-iGluSnFR.

Thyrotropin-releasing hormone induces Ca increase in a subset of vagal nodose ganglion neurons.

Thyrotropin-releasing hormone (TRH) plays a central role in metabolic homeostasis, and single-cell sequencing has recently demonstrated that vagal sensory neurons in the nodose ganglion express thyrotropin-releasing hormone receptor 1 (TRHR1). Here, in situ hybridization validated the presence of TRHR1 in nodose ganglion (NG) neurons and immunohistochemistry showed that the receptor is expressed at the protein level. However, it has yet to be demonstrated whether TRHR1 is functionally active in NG neurons.

Bile acids induce Ca signaling and membrane permeabilizations in vagal nodose ganglion neurons.

Bile acids (BAs) play an important role in the digestion of dietary fats and act as signaling molecules. However, due to their solubilizing properties, high concentrations in the gut may negatively affect gut epithelium and possibly afferent fibers innervating the gastrointestinal tract (GI). To determine the effect of BAs on intracellular Ca and membrane permeabilization we tested a range of concentrations of two BAs on vagal nodose ganglion (NG) neurons, Chinese Hamster Ovary (CHO), and PC12 cell lines.

NPFF Decreases Activity of Human Arcuate NPY Neurons: A Study in Embryonic-Stem-Cell-Derived Model.

Restoring the control of food intake is the key to obesity management and prevention. The arcuate nucleus (ARC) of the hypothalamus is extensively being studied as a potential anti-obesity target. Animal studies showed that neuropeptide FF (NPFF) reduces food intake by its action in neuropeptide Y (NPY) neurons of the hypothalamic ARC, but the detailed mode of action observed in human neurons is missing, due to the lack of a human-neuron-based model for pharmacology testing.

GABAergic Inhibition of Presynaptic Ca Transients in Respiratory PreBötzinger Neurons in Organotypic Slice Cultures.

GABAergic somatodendritic inhibition in the preBötzinger complex (preBötC), a medullary site for the generation of inspiratory rhythm, is involved in respiratory rhythmogenesis and patterning. Nevertheless, whether GABA acts distally on presynaptic terminals, evoking presynaptic inhibition is unknown. Here, we begin to address this problem by measuring presynaptic Ca transients in preBötC neurons, under rhythmic and non-rhythmic conditions, with two variants of genetically encoded Ca indicators (GECIs).