Responses of spinal cord neurons following stimulation of Aβ femoral-saphenous venous afferent fibers

摘要: A population of large (A beta) afferents is known to have endings in the wall femoral-saphenous vein. These project lower lumbar spinal cord. The purpose present study was identify, localize, and characterize neurons that receive inputs from such afferents. Responses 50 L6 cord segment decerebrate-spinal cats or intact anesthetized using alpha-chloralose were recorded following electrical stimulation these Observations also made on convergence muscle cutaneous afferent onto driven by terminating All recording sites marked either intracellularly staining element characterized with HRP extracellularly iontophoresing a small quantity this tracer. cells for long durations (mean 51.5 ms, S.E.M. 10.0) single-shock venous located Rexed's laminae IV-VIII X. Eight activated at latencies equal shorter than first negative wave dorsum potential; units mean latency 1.4 ms (S.E.M. 0.25) arrival volley assumed monosynaptic, least relatively direct, primary Most (6 8) lamina V. majority studied (37 50) longer 3 cord; about half (19 37) those VII, rest scattered among other laminae. Twenty-eight 40 afferent-driven tested could be posterior tibial sural nerve. In general, intensities necessary activate only sufficient excite alpha Neurons receiving shortest vein less likely convergent skin latency.