The effects of stimulating locus coeruleus (LC) and nucleus raphe magnus (NRM) on lumbar dorsal horn cells that had been denervated by dorsal rhizotomy were studied. Both LC and NRM stimulation inhibited the responses of dorsal horn cells from the side of the cord with intact dorsal roots. However, when cells from the side of the spinal cord that had had prior rhizotomies were studied, half of ...

As different classes of sensory neurons project into the CNS, their axons segregate and establish distinct trajectories and target zones. One striking instance of axonal segregation is the projection of sensory neurons into the spinal cord, where proprioceptive axons avoid the superficial dorsal horn-the target zone of many cutaneous afferent fibers. PlexinA1 is a proprioceptive sensory axon-sp...

The present study was aimed to examine if protein kinase C (PKC) activation is necessarily involved in both the c-fos protein expression in the nocuously-activated c-fos protein-like immunoreactive (Fos-LI) neurons and the concomitant opioid receptor-mediated modulation in the dorsal horn circuitry of the spinal cord. Formalin was injected into a hindpaw of rats 5 min after the rats were pretre...

We have investigated whether neurons in superficial laminae of the spinal dorsal horn respond to intracutaneous (ic) delivery of histamine and other irritant chemicals, and thus might be involved in signaling sensations of itch or chemogenic pain. Single-unit recordings were made from superficial lumbar dorsal horn neurons in pentobarbital sodium-anesthetized rats. Chemoresponsive units were id...

A-type potassium currents are important determinants of neuronal excitability. In spinal cord dorsal horn neurons, A-type currents are modulated by extracellular signal-regulated kinases (ERKs), which mediate central sensitization during inflammatory pain. Here, we report that Kv4.2 mediates the majority of A-type current in dorsal horn neurons and is a critical site for modulation of neuronal ...

The extracellular signal-regulated kinase (Erk) cascades are suggested to contribute to excitatory synaptic plasticity in the CNS, including the spinal cord dorsal horn. However, many of their upstream signaling pathways remain to be investigated. Here, we demonstrate that glutamate and substance P (SP), two principal mediators of sensory information between primary afferent fibers and the spin...

INTRODUCTION Spinal Cord Injury (SCI) results in a loss of function such as mobility or feeling. SCI can be divided into two types of injury complete and incomplete. A complete injury means that there is no function below the level of the injury; no sensation and no voluntary movement. An incomplete injury means that there is some functioning below the primary level of the injury. A patient wit...

Disinhibition in the dorsal horn accompanies peripheral nerve injury and causes the development of hypersensitivity to mild stimuli. This demonstrates the critical importance of inhibition in the dorsal horn for maintaining normal sensory signaling. Here we show that disinhibition induces a novel polysynaptic low-threshold input onto lamina I output neurons, suggesting that inhibition normally ...

Localization and ultrastructural features of immunoreactive fibers and terminals against RT-97, a mouse monoclonal antibody that recognizes subunit of a 200-kD neurofilament, were examined in the spinal dorsal horn of adult rats. Under a light-microscope, many RT-97 immunoreactive fibers were detected in the dorsal root, collaterals of the dorsal root in the dorsal funiculus, and laminae III an...