A computational model of the integration of noxious and innocuous input in the dorsal horn

AbstractThe first site for a synaptic relay in the somatosensory nervous system is the spinal cord, where peripheral afferents synapse onto interneurons and projection neurons. Here, we present a model of the integration of noxious and innocuous somatosensory afferent input in the dorsal horn of the spinal cord. This model specifically examines the interaction of nociceptive responsive, innocuous responsive, and inhibitory interneurons, all of which receive afferent input from the periphery and in turn synapse onto projection neurons that transmit information to supraspinal neural circuits for further processing. We modeled the dynamics of these neuronal populations using a rate-based Wilson-Cowan approach. The model successfully recreates common observations related to noxious and innocuous stimulation, as well as the resulting intensity of pain. Furthermore, we explored how modifications of the synaptic connections between the different neuron populations can give rise to aberrant pain. These explorations provide insights into the possible mechanisms of neuropathic pain conditions such as phantom limb pain, hyperalgesia, and allodynia.