A glutamatergic innervation from medial area of secondary visual cortex to lateral posterior thalamic nucleus facilitates nociceptive and neuropathic pain.

Neuropathic pain involves complex cortical mechanisms, yet the role of the medial secondary visual cortex (V2M) remains poorly understood. We hypothesized that glutamatergic neurons in V2M (V2M) contribute to pain modulation and explored their functional involvement in both normal and neuropathic pain states. Here, we found that V2M could be activated by peripheral stimulation under normal conditions.

Ventral posteromedial nucleus of the thalamus gates the spread of trigeminal neuropathic pain.

Background: Widespread neuropathic pain usually affects a wide range of body areas and inflicts huge suffering on patients. However, little is known about how it happens and effective therapeutic interventions are lacking.

Methods: Widespread neuropathic pain was induced by partial infraorbital nerve transection (p-IONX) and evaluated by measuring nociceptive thresholds.

Glutamatergic and GABAergic neurons in the vLGN mediate the nociceptive effects of green and red light on neuropathic pain.

Phototherapy is an emerging non-pharmacological treatment for depression, circadian rhythm disruptions, and neurodegeneration, as well as pain conditions including migraine and fibromyalgia. However, the mechanism of phototherapy-induced antinociception is not well understood. Here, using fiber photometry recordings of population-level neural activity combined with chemogenetics, we found that phototherapy elicits antinociception via regulation of the ventral lateral geniculate body (vLGN) located in the visual system.