Nitrous Oxide activates layer 5 prefrontal neurons via SK2 channel inhibition for antidepressant effect.

Nitrous oxide (NO) induces rapid and durable antidepressant effects. The cellular and circuit mechanisms mediating this process are not known. Here we find that a single dose of inhaled NO induces rapid and specific activation of layer V (L5) pyramidal neurons in the cingulate cortex of rodents exposed to chronic stress conditions.

Sertraline modulates hippocampal plasticity via sigma 1 receptors, cellular stress and neurosteroids.

In addition to modulating serotonin transport, selective serotonin reuptake inhibitors (SSRIs) have multiple other mechanisms that may contribute to clinical effects, and some of these latter actions prompt repurposing of SSRIs for non-psychiatric indications. In a recent study of the SSRIs fluvoxamine, fluoxetine and sertraline we found that, unlike the other two SSRIs, sertraline acutely inhibited LTP at a low micromolar concentration through inverse agonism of sigma 1 receptors (S1Rs). In the present studies, we pursued mechanisms contributing to sertraline modulation of LTP in rat hippocampal slices.

Synthesis and evaluation of photoaffinity labeling reagents for identifying binding sites of sulfated neurosteroids on NMDA and GABA receptors.

The endogenous neurosteroids dehydroepiandrosterone sulfate (DHEAS) and pregnenolone sulfate (PS) are allosteric modulators of γ-aminobutyric acid type A (GABA) and -methyl-d-aspartate (NMDA) type glutamate receptors. Analogues of these endogenous steroid sulfates can be either positive or negative allosteric modulators (PAMs or NAMs, respectively) of these receptors, but there is limited information about the steroid-protein binding interactions that mediate these effects and photoaffinity labeling reagents (PALs) of sulfated steroids have not been reported previously. The synthesis of a panel of ten sulfated steroid analogues containing a diazirine group, five of which also contain an alkyne group for click chemistry reactions, for use in photoaffinity labeling studies to identify binding sites for steroid sulfates that are either positive or negative allosteric modulators is reported.

Nitrous Oxide Alters Functional Connectivity in Medial Limbic Structures in Treatment-Resistant Major Depression.

While nitrous oxide (NO) has demonstrated antidepressant properties in treatment-resistant major depression (TRD), little is known about neural mechanisms mediating these effects. Employing serial resting-state functional magnetic resonance imaging (rs-fMRI), we compared spatiotemporal effects of inhaled NO on brain functional connectivity in TRD patients (n=14) and non-depressed healthy controls (n=16, CNTL). Participants received sequential, one-hour inhalations of either 50% NO/oxygen or air/oxygen (placebo), with sessions separated by at least one month in random cross-over order.

Modeling late-onset Alzheimer's disease neuropathology via direct neuronal reprogramming.

Late-onset Alzheimer's disease (LOAD) is the most common form of Alzheimer's disease (AD). However, modeling sporadic LOAD that endogenously captures hallmark neuronal pathologies such as amyloid-β (Aβ) deposition, tau tangles, and neuronal loss remains an unmet need. We demonstrate that neurons generated by microRNA (miRNA)-based direct reprogramming of fibroblasts from individuals affected by autosomal dominant AD (ADAD) and LOAD in a three-dimensional environment effectively recapitulate key neuropathological features of AD.