THERMOREGULATORY AND RHYTHM-GENERATING MECHANISMS GOVERNING THE SUDOMOTOR AND VASOCONSTRICTOR OUTFLOW IN HUMAN CUTANEOUS NERVES
THERMOREGULATORY AND RHYTHM-GENERATING MECHANISMS GOVERNING THE SUDOMOTOR AND VASOCONSTRICTOR OUTFLOW IN HUMAN CUTANEOUS NERVES
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DOI：
10.1113/jphysiol.1980.sp013413
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发表时间：
1980-01-01
影响因子：
5.5
通讯作者：
WALLIN, BG
中科院分区：
文献类型：
--
作者：
BINI, G;HAGBARTH, KE;WALLIN, BG
对暴露于不同环境温度下的健康受试者的四肢毛状和无毛状皮肤的神经束进行了多单位交感神经活动的记录。通过同时记录神经支配区皮电和脉搏容积描记事件（Pleth）来监测伴随神经活动的舒缩和血管舒缩事件。将实验对象暴露在摄氏43度的温暖环境中。C)或冷（15度）。C)环境中，有可能分别选择性地激活压迫神经系统或血管收缩神经系统，同时抑制另一个系统的自发活动。血管收缩和压迫神经活动的爆发以一定的优选间隔发生，间隔为约0.6秒（100周期/分钟）周期的整数倍。高抑制性或血管收缩性音调时，100周期/分节律显著，而低音调时，较慢的次谐波节律占优势。呼吸节奏也被认为是由于体温调节伺服机制的振荡倾向而导致的较慢的节奏。血管收缩脉冲的平均持续时间比强动性脉冲长，这一发现归因于与强动性脉冲相比，血管收缩脉冲的传导速度较慢。随着脉冲发生率的增加，单个脉冲后的瞬态皮电或脉搏波反应合并，因此在皮电或脉搏波痕迹中都无法识别快速的神经节律。给定神经放电速率的增量，在高放电速率下比在低放电速率下产生更少的额外血管收缩。节律产生机制可能有助于将单个纤维的放电速率限制在低范围内，从而在神经效应传递函数中提供高增益。
Recordings of multiunit sympathetic activity were made from human nerve fascicles supplying hairy and glabrous skin of the extremities in healthy subjects exposed to different ambient temperatures. Sudomotor and vasomotor events accompanying the neural activity were monitored by simultaneous recordings of electrodermal and pulse plethysmographic events (Pleth) in the neural innervation zones. By exposing the subject to warm (43.degree. C) or cold (15.degree. C) environments, it was possible to obtain a selective activation of either the sudomotor or the vasoconstrictor neural system, respectively, with suppression of spontaneous activity in the other system. Bursts of both vasoconstrictor and sudomotor nerve activity occurred at certain preferred intervals which were integer multiplies of a period of about 0.6 sec (100 cycles/min). With high sudomotor or vasoconstrictor tone the 100 cycles/min rhythm was prominent but with decreasing tone slower subharmonic rhythms prevailed. Respiratory rhythms were also discerned as were slower rhythms attributable to oscillatory tendencies in thermoregulatory servomechanisms. Vasoconstrictor bursts had longer mean duration than sudomotor bursts, a finding attributed to a slower conduction velocity of vasoconstrictor as compared to sudomotor impulses. With increasing incidence of bursts transient electrodermal or plethysmographic responses following individual bursts merged, and thus the fast neural rhythms were not discernible in either the electrodermal or Pleth traces. Given increments in firing rate of nerves produced less additional vasoconstriction at high than at low firing rates. The rhythm generating mechanisms may help to restrict firing rates of individual fibers to the low range which provides high gain in the neuroeffector transfer functions.