What is the Mechanism of Pain Modulation in the Spinal Cord?
Pain modulation in the spinal cord involves both excitatory and inhibitory pathways:
1. Excitatory Pathways: Nociceptive signals are transmitted by primary afferent fibers (A-delta and C fibers) to the dorsal horn, where they synapse with second-order neurons. These neurons then project to higher brain centers, facilitating pain perception. 2. Inhibitory Pathways: Inhibitory interneurons release neurotransmitters such as GABA (gamma-aminobutyric acid) and glycine, which can dampen the excitatory signals. Additionally, descending pathways from the brainstem release endogenous opioids and other neuromodulators that suppress pain transmission.
