Intrinsic adaptive plasticity in mouse and human sensory neurons.

In response to changes in activity induced by environmental cues, neurons in the central nervous system undergo homeostatic plasticity to sustain overall network function during abrupt changes in synaptic strengths. Homeostatic plasticity involves changes in synaptic scaling and regulation of intrinsic excitability. Increases in spontaneous firing and excitability of sensory neurons are evident in some forms of chronic pain in animal models and human patients.

Harmonized cross-species cell atlases of trigeminal and dorsal root ganglia.

Sensory neurons in the dorsal root ganglion (DRG) and trigeminal ganglion (TG) are specialized to detect and transduce diverse environmental stimuli to the central nervous system. Single-cell RNA sequencing has provided insights into the diversity of sensory ganglia cell types in rodents, nonhuman primates, and humans, but it remains difficult to compare cell types across studies and species. We thus constructed harmonized atlases of the DRG and TG that describe and facilitate comparison of 18 neuronal and 11 non-neuronal cell types across six species and 31 datasets.

Bradykinin receptor expression and bradykinin-mediated sensitization of human sensory neurons.

Bradykinin is a peptide implicated in inflammatory pain in both humans and rodents. In rodent sensory neurons, activation of B1 and B2 bradykinin receptors induces neuronal hyperexcitability. Recent evidence suggests that human and rodent dorsal root ganglia (DRG), which contain the cell bodies of sensory neurons, differ in the expression and function of key GPCRs and ion channels; whether bradykinin receptor expression and function are conserved across species has not been studied in depth.

Intrinsic Homeostatic Plasticity in Mouse and Human Sensory Neurons.

In response to changes in activity induced by environmental cues, neurons in the central nervous system undergo homeostatic plasticity to sustain overall network function during abrupt changes in synaptic strengths. Homeostatic plasticity involves changes in synaptic scaling and regulation of intrinsic excitability. Increases in spontaneous firing and excitability of sensory neurons are evident in some forms of chronic pain in animal models and human patients.

Bradykinin receptor expression and bradykinin-mediated sensitization of human sensory neurons.

Bradykinin is a peptide implicated in inflammatory pain in both humans and rodents. In rodent sensory neurons, activation of B1 and B2 bradykinin receptors induces neuronal hyperexcitability. Recent evidence suggests that human and rodent dorsal root ganglia (DRG), which contain the cell bodies of sensory neurons, differ in the expression and function of key GPCRs and ion channels; whether BK receptor expression and function are conserved across species has not been studied in depth.

TMEM120A/TACAN inhibits mechanically activated PIEZO2 channels.

PIEZO2 channels mediate rapidly adapting mechanically activated currents in peripheral sensory neurons of the dorsal root ganglia (DRG), and they are indispensable for light touch and proprioception. Relatively little is known about what other proteins regulate PIEZO2 activity in a cellular context. TMEM120A (TACAN) was proposed to act as a high threshold mechanically activated ion channel in nociceptive DRG neurons.

Crowding-induced opening of the mechanosensitive Piezo1 channel in silico.

Mechanosensitive Piezo1 channels are essential mechanotransduction proteins in eukaryotes. Their curved transmembrane domains, called arms, create a convex membrane deformation, or footprint, which is predicted to flatten in response to increased membrane tension. Here, using a hyperbolic tangent model, we show that, due to the intrinsic bending rigidity of the membrane, the overlap of neighboring Piezo1 footprints produces a flattening of the Piezo1 footprints and arms.

Gi-coupled receptor activation potentiates Piezo2 currents via Gβγ.

Mechanically activated Piezo2 channels are key players in somatosensory touch, but their regulation by cellular signaling pathways is poorly understood. Dorsal root ganglion (DRG) neurons express a variety of G-protein-coupled receptors that modulate the function of sensory ion channels. Gi-coupled receptors are generally considered inhibitory, as they usually decrease excitability.

Structure-based characterization of novel TRPV5 inhibitors.

Transient receptor potential vanilloid 5 (TRPV5) is a highly calcium selective ion channel that acts as the rate-limiting step of calcium reabsorption in the kidney. The lack of potent, specific modulators of TRPV5 has limited the ability to probe the contribution of TRPV5 in disease phenotypes such as hypercalcemia and nephrolithiasis. Here, we performed structure-based virtual screening (SBVS) at a previously identified TRPV5 inhibitor binding site coupled with electrophysiology screening and identified three novel inhibitors of TRPV5, one of which exhibits high affinity, and specificity for TRPV5 over other TRP channels, including its close homologue TRPV6.

Death Associated Protein Kinase (DAPK) -mediated neurodegenerative mechanisms in nematode excitotoxicity.

Background: Excitotoxicity (the toxic overstimulation of neurons by the excitatory transmitter Glutamate) is a central process in widespread neurodegenerative conditions such as brain ischemia and chronic neurological diseases. Many mechanisms have been suggested to mediate excitotoxicity, but their significance across diverse excitotoxic scenarios remains unclear. Death Associated Protein Kinase (DAPK), a critical molecular switch that controls a range of key signaling and cell death pathways, has been suggested to have an important role in excitotoxicity.

Tumor necrosis factor-α inhibitors alleviation of experimentally induced neuropathic pain is associated with modulation of TNF receptor expression.

Inflammation plays a key role in the development of sensitization after peripheral nerve damage. We recently demonstrated that tumor necrosis factor-α receptor (TNFR) levels in the spinal cord correlate with pain sensation in herniated disc patients in a rat chronic constriction injury (CCI) model. By using the sciatic nerve CCI model, we studied the effect of anti-TNF-α treatment on recovery from hypersensitivity and TNFR expression in the dorsal root ganglion (DRG) and dorsal horn (DH).

The thalidomide analgesic effect is associated with differential TNF-α receptor expression in the dorsal horn of the spinal cord as studied in a rat model of neuropathic pain.

The proinflammatory cytokine tumor necrosis factor-α (TNF-α) is well recognized as a key player in nociceptive signaling. Yet, therapeutic capitalization of this knowledge requires a better understanding of how TNF receptors (TNFR) contribute to pain. To address this question, we studied TNFR expression in the chronic sciatic nerve constriction (CCI) model of neuropathic pain.