Pain Basics & Education | Advanced Spine and Pain | Updated April 2026
Introduction: Why Your Pain Keeps Firing
Sodium channels pain research has transformed how medicine understands and treats chronic pain — and in 2025, it delivered the first new non-opioid painkiller approved in decades.
Every time you feel pain, tiny protein gates called voltage-gated sodium channels are at work. They open, flood nerve cells with electrical charge, and fire a signal from the injury site straight to your brain. The role of sodium channels in pain signaling is now one of the most actively researched areas in all of neuroscience — and understanding it matters not just for scientists, but for anyone living with chronic or neuropathic pain.
This article explains how sodium channels drive pain neuroscience, which subtypes are most critical, why inflammation makes pain worse at the molecular level, and what the latest therapies mean for patients. No PhD required.
What Are Voltage-Gated Sodium Channels?
Every sensation you feel — touch, temperature, pressure, pain — begins with an electrical signal. Neurons generate these signals through a process called an action potential: a rapid shift in electrical charge across the cell membrane.
Voltage-gated sodium channels (VGSCs, also written as Nav channels) are the molecular switches that make this possible. When a neuron is stimulated, these channels snap open, flooding the cell with positively charged sodium ions. That inrush of charge creates the rising phase of the action potential — the electrical impulse that carries pain information from your fingertips to your brain.
There are nine known subtypes (Nav1.1 through Nav1.9), each encoded by a different gene and expressed in different tissues. The three that matter most for pain — Nav1.7, Nav1.8, and Nav1.9 are predominantly found in peripheral sensory neurons, particularly in structures called dorsal root ganglia (DRG), the clusters of nerve cell bodies just outside the spinal cord.
This peripheral expression is critical. Because these channels operate mostly outside the central nervous system, blocking them selectively offers the possibility of pain relief without affecting the brain — a key advantage over opioids.
The Pain Signaling Mechanism: From Stimulus to Perception
Before examining individual sodium channel subtypes, it helps to understand the four-stage journey a pain signal makes. If you want a broader look at how these signals relate to different pain types, our article on Acute, Chronic & Neuropathic Pain: What’s the Difference? is a good companion read.
Detection begins at specialized sensory nerve endings called nociceptors — the biological equivalent of a fire alarm. When these endings detect a harmful stimulus (heat, pressure, a chemical irritant), sodium channels open and an action potential is triggered.
Peripheral transmission carries that electrical signal along sensory nerve fibers from the site of injury toward the spinal cord. This is where Nav1.7 and Nav1.8 do most of their work in the nociception pathway, sustaining and amplifying the signal as it travels.
Central transmission happens when the signal reaches the dorsal horn of the spinal cord, where it crosses a synapse and ascends toward the brain via dedicated nociceptive pathways.
Perception occurs in the brain — in the thalamus, somatosensory cortex, and limbic system — where the raw signal is interpreted as pain, and the emotional and cognitive dimensions of that experience take shape.
This is the journey that targeted sodium channel therapies are designed to interrupt.
Sodium Channels Pain Research: Nav1.7 and Nav1.8 Explained
Nav1.7: The Threshold Channel in Pain Neuroscience
Nav1.7 is often described as the “threshold channel” because it determines whether a nociceptor fires at all. It is exquisitely sensitive to small, subthreshold changes in membrane voltage — essentially acting as an amplifier that decides whether a weak signal is strong enough to launch a full action potential.
The genetic evidence for Nav1.7’s role in pain is some of the most compelling in medicine. Rare inherited mutations in the SCN9A gene (which encodes Nav1.7) that increase channel activity cause devastating chronic pain syndromes, including primary erythromelalgia — a condition marked by severe burning pain in the hands and feet. At the other extreme, individuals born with loss-of-function mutations in SCN9A feel no pain whatsoever. They can break bones, burn themselves, and undergo surgery with no pain response at all.
This complete insensitivity to pain — with no other major neurological deficits — made Nav1.7 the most exciting drug target in pain medicine for over a decade. If you could block it selectively, you could theoretically eliminate pain without the side effects of opioids or the bluntness of general anesthetics.
The clinical reality proved more complicated, and we will return to that shortly.
Nav1.8: The Workhorse of Inflammatory and Neuropathic Pain
Nav1.8, encoded by the SCN10A gene, has a distinct and important property: it is tetrodotoxin-resistant. Most sodium channels are instantly blocked by tetrodotoxin (the famous puffer fish toxin), but Nav1.8 keeps working. This resistance allows it to maintain pain signaling even in the acidic, chemically complex environment created by tissue inflammation — precisely the conditions under which pain is at its worst.
Nav1.8 is responsible for the large, sustained inward current that drives the upstroke of action potentials in nociceptors. In inflammatory and neuropathic pain states, its expression increases, contributing to the heightened electrical excitability that makes chronic pain feel amplified and relentless.
Critically, Nav1.8 is expressed almost exclusively in peripheral sensory neurons — making it, in pharmacological terms, a near-perfect drug target. A compound that selectively blocks Nav1.8 can interrupt pain signals at their source without affecting the brain, heart, or motor neurons.
Nav1.9: The Quiet Background Channel
Nav1.9 generates a slow, persistent sodium current that modulates the resting state of nociceptors — setting how close to firing threshold they sit at baseline. It appears most relevant to cold pain sensing and visceral pain, and gain-of-function mutations have been identified in patients with small fiber neuropathy. Research into its full clinical significance is ongoing.
How Inflammation Sensitizes Sodium Channels
Understanding why chronic pain persists long after the original injury requires understanding what inflammation does to sodium channels at the molecular level. This is also a key reason why conditions like Complex Regional Pain Syndrome (CRPS) generate pain that far outlasts any visible tissue damage.
When tissue is damaged, the immune system releases a cascade of inflammatory mediators — prostaglandins, bradykinin, cytokines like IL-1β and TNF-α, and nerve growth factor (NGF). These molecules bind to receptors on nociceptors and trigger intracellular signaling cascades involving protein kinases PKA and PKC.
These kinases then phosphorylate Nav1.7 and Nav1.8 — attaching a chemical signal that fundamentally changes channel behavior. The result is a lowered activation threshold. Channels that previously required a strong stimulus to open can now be triggered by stimuli that are normally harmless — a condition called peripheral sensitization.
This is the molecular basis of allodynia (pain from normally non-painful touch) and hyperalgesia (exaggerated pain from normally mild stimuli). If you have ever winced at clothing touching sunburned skin, you have experienced peripheral sensitization firsthand.
Over time, if inflammation persists or nerve injury occurs, sodium channel expression itself changes. Channels cluster abnormally at injured nerve endings, generating spontaneous electrical activity called ectopic discharge — which the brain interprets as ongoing pain even when no harmful stimulus is present. Research also shows that psychological stress can amplify this process, lowering pain thresholds and heightening nociceptive circuit sensitivity.
For patients: This is why your chronic pain is not “all in your head.” It reflects measurable, physiological changes in how your neurons express and fire through voltage-gated sodium channels.
Sodium Channel Blockers: Targeted Treatments for Pain
The Promise and Puzzle of Nav1.7 Blockers
Given the genetic evidence, Nav1.7 seemed like the ideal drug target. Multiple pharmaceutical companies developed highly selective Nav1.7 inhibitors, and preclinical animal results were consistently impressive. Yet in human clinical trials, these drugs repeatedly fell short.
Emerging research offers a compelling explanation: nociceptors may be able to compensate for the loss of Nav1.7 by upregulating other Nav subtypes. The system achieves similar excitability through different channels — a form of biological redundancy that protects pain signaling even when one component is blocked.
Novel gene therapy approaches targeting specific regulatory sequences within Nav1.7 have shown reversal of mechanical pain hypersensitivity in animal models, so the research is far from over.
The Nav1.8 Breakthrough: Suzetrigine (Journavx)
The clearest recent success in sodium channels pain research arrived in January 2025. The FDA approved suzetrigine (brand name Journavx), a selective Nav1.8 inhibitor developed by Vertex Pharmaceuticals, for moderate to severe acute pain — the first genuinely new mechanism-based analgesic approved in decades.
Suzetrigine demonstrated more than 31,000-fold selectivity for Nav1.8 over other Nav subtypes. In Phase III trials with surgical patients, it produced clinically meaningful pain score reductions, with rapid onset and no respiratory depression, sedation, or addiction signal.
Because Nav1.8 is expressed peripherally rather than in the brain, suzetrigine avoids the central side effects associated with opioids. It is proof-of-concept that the sodium channel pain targeting strategy, refined to the right subtype, works in humans.
Research into its potential for chronic pain — including diabetic peripheral neuropathy — continues in multiple Phase III trials.
Combination and Multi-Subtype Strategies
With single-subtype blockers showing inconsistent results for chronic pain, researchers are exploring multi-target approaches. Investigational compounds that simultaneously block Nav1.7, Nav1.8, and Nav1.9 have shown broad analgesic efficacy in neuropathic and inflammatory pain models, with strong safety profiles and negligible effects on motor function. Blocking the entire redundancy network — rather than a single node — may be necessary for durable chronic pain relief.
What Sodium Channels Pain Science Means for Your Treatment
For patients with acute pain from surgery or injury, suzetrigine is already available in the United States as a non-opioid option. For patients with inflammatory spine or nerve pain, treatments like epidural steroid injections remain effective by reducing the very inflammation that drives sodium channel sensitization — addressing pain upstream of the channels themselves.
For those with neuropathic or chronic pain, the pipeline is more active than it has been in decades. Genetic testing for sodium channel variants (particularly SCN9A) is increasingly guiding personalized pain management decisions, helping identify patients most likely to respond to channel-targeted therapies.
Most importantly, this science validates what patients have always known: chronic pain is not weakness. It is the result of documented, measurable changes in how neurons express, regulate, and fire through voltage-gated sodium channels.
Frequently Asked Questions
What is the role of sodium channels in pain? Voltage-gated sodium channels — especially Nav1.7, Nav1.8, and Nav1.9 — generate and propagate the action potentials that carry pain information from injured tissue to the brain. Without these channels, pain signals cannot travel.
How does a pain signal travel to the brain? A noxious stimulus activates nociceptors, which open sodium channels and generate an action potential. This signal travels along peripheral nerves to the spinal cord, crosses a synapse in the dorsal horn, and ascends via spinothalamic tracts to pain-processing regions of the brain.
Why is Nav1.7 so important in sodium channels pain research? Nav1.7 sets the firing threshold for nociceptors. Humans born without functional Nav1.7 feel no pain at all — one of the most powerful genetic validations of any drug target in medicine.
Are there approved drugs that target sodium channels for pain? Yes. Suzetrigine (Journavx), FDA-approved in January 2025, selectively blocks Nav1.8 and is the first new non-opioid pain mechanism approved in decades. Older non-selective sodium channel blockers like lidocaine and carbamazepine have also been used in pain management for years.
Key Takeaways
Sodium channels are the molecular foundation of pain signaling. Nav1.7 sets the firing threshold, Nav1.8 sustains the signal under inflammatory conditions, and Nav1.9 modulates baseline nociceptor excitability. Inflammation biochemically lowers the activation threshold of these channels — explaining why chronic pain persists and amplifies. The 2025 FDA approval of suzetrigine proves that selective sodium channel pain targeting can deliver real non-opioid relief in humans. The next frontier is combination strategies and chronic pain indications, where science is advancing faster than at any point in history.
Dealing with chronic or neuropathic pain? The specialists at Advanced Spine and Pain are here to help. Call 877-250-2727 to schedule a consultation at one of our locations across Virginia, Maryland, and Delaware.
