Temporal patterning in the responses of gracile and cuneate neurones in the cat to cutaneous vibration.

AUTOR(ES)

Ferrington, D G

RESUMO

1. Recordings were made in decerebrate cats from gracile and cuneate neurones responding to vibration-induced inputs from Pacinian corpuscle (P.c.) receptors of the hind-limb and forelimb footpads. The two groups of neurones were compared, in particular for their capacities for responding to cutaneous vibration with phase-locked impulse patterns. 2. In both nuclei the P.c. neurones were most sensitive to vibration in the range 80 to greater than 600 Hz. Stimulus-response relations were similar for the two groups, as were measures derived from these relations such as response levels, absolute thresholds and the dynamic range (defined as the vibration amplitude range over which responses were graded). 3. At frequencies up to 300-400 Hz, responses for some neurones in both nuclei remained well phase locked to the vibration; however, quantitative analysis using a factorial analysis of variance indicated that the phase locking was poorer in gracile than cuneate neurones. 4. In both nuclei there was marked variability from neurone to neurone in measures of phase locking which may reflect variations in the extent of convergence of P.c. fibres upon different target neurones. For neurones in either nucleus that had comparatively tight phase locking of responses to vibration it is proposed that their output is functionally dominated by one or a few of their convergent P.c. input fibres.

Documentos Relacionados

• Timing of corticofugal actions on the gracile and cuneate nuclei of the cat.
• Cutaneous excitatory and inhibitory input to neurones of the postsynaptic dorsal column system in the cat.
• Serum endothelin concentrations in workers exposed to vibration.
• Synaptic transmission between single slowly adapting type I fibres and their cuneate target neurones in cat.
• An intracellular study of descending and non-cutaneous afferent input to spinocervical tract neurones in the cat.