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Identification of afferent C units in intact human skin nerves
Pain, 1 (1975) 183--194 © Elsevier/North-Holland, Amsterdam
183
Abstracts These abstracts have been selected and written by the Editorial Panel Leaders.
PHYSIOLOGY
.Identification of afferent C units in intact human skin nerves H. E. Torebjfrk and R. G. Hallin, Brain Res., 67 (1974) 287-403
Single unit potentials were recorded with microelectrodes from intact human skin nerves, and unitary responses to electrical and natural skin stimuli were studied., The unitary discharges were derived from afferent C fibres since the impulses wele conducted at C velocity and persisted after preferential blocking of activity in myelinated fibres by nerve compresfion, whereas they were abolished before the A fibre discharges by lidoeaine. The afferent C units adapted slowly to mechanie~,! stimuli and in some of them afterdischarges followed when the stimuli were withdrawn. 1~epeated mechanical stimulation decreased the e~:citz.bi!ity. Intense stimuli such as pinpricks or heat stimulation elicited most vigorous responses. The responses of the human C units to different stimuli were reminiscent of responses in 'polymodaI' C rcceptor~ identified in the cat and the monkey. The mo~t intev..se discharges in the uliit.~, were elicited by painful stimuli, but a considerable activity was also aroused oy non-painful ones. Single or a few repeated impulses in an afferent C unit need not be perceived at all.
Perceptual changes accompanyir,g controlled preferential blocking of A and C fibre responses in intact human skin nerves H. E. Torebj6rk and R. G. Hallin, Exp. Brahl Res., i6 (1973) 321-332 In awake human subjects, electrically induced A and C fibre responses were recorded from skin nerves with percutaneously inserted tungsten microelectrodes. By studying the influence of preferential blocking manoeavres upon the nerve response, activity in A and C fibres was correlated with sensatior. Injection oflidocaine of a tow concentration between the stimulaling and recording sites abolished the C wax~es. When mainly A fibre activity was record,.~d, weak elect~;ic skin shocks were still felt as :t tactile sensation. A strong stimulus was perceived as a short, sometimes sharp blow,
183
Abstracts These abstracts have been selected and written by the Editorial Panel Leaders.
PHYSIOLOGY
.Identification of afferent C units in intact human skin nerves H. E. Torebjfrk and R. G. Hallin, Brain Res., 67 (1974) 287-403
Single unit potentials were recorded with microelectrodes from intact human skin nerves, and unitary responses to electrical and natural skin stimuli were studied., The unitary discharges were derived from afferent C fibres since the impulses wele conducted at C velocity and persisted after preferential blocking of activity in myelinated fibres by nerve compresfion, whereas they were abolished before the A fibre discharges by lidoeaine. The afferent C units adapted slowly to mechanie~,! stimuli and in some of them afterdischarges followed when the stimuli were withdrawn. 1~epeated mechanical stimulation decreased the e~:citz.bi!ity. Intense stimuli such as pinpricks or heat stimulation elicited most vigorous responses. The responses of the human C units to different stimuli were reminiscent of responses in 'polymodaI' C rcceptor~ identified in the cat and the monkey. The mo~t intev..se discharges in the uliit.~, were elicited by painful stimuli, but a considerable activity was also aroused oy non-painful ones. Single or a few repeated impulses in an afferent C unit need not be perceived at all.
Perceptual changes accompanyir,g controlled preferential blocking of A and C fibre responses in intact human skin nerves H. E. Torebj6rk and R. G. Hallin, Exp. Brahl Res., i6 (1973) 321-332 In awake human subjects, electrically induced A and C fibre responses were recorded from skin nerves with percutaneously inserted tungsten microelectrodes. By studying the influence of preferential blocking manoeavres upon the nerve response, activity in A and C fibres was correlated with sensatior. Injection oflidocaine of a tow concentration between the stimulaling and recording sites abolished the C wax~es. When mainly A fibre activity was record,.~d, weak elect~;ic skin shocks were still felt as :t tactile sensation. A strong stimulus was perceived as a short, sometimes sharp blow,