Characteristics of Receptors and Afferent Fibres of the Forelimb Interosseous Nerve of the Cat

Publisher Website
Google Scholar
Abstract
Silfvenius, H. Characteristics of receptors and afferent fibres of the forelimb interosseous nerve of the cat. Acta physiol. scand. 1970. 79. 6–23.A description is given for dissection and identification of the forelimb interosseous nerve, Int. f., a branch of the median nerve. The nerve contained on average 225 axons. The measured diameters of the myelinated axons of the Int. f. ranged between 1 and 16 μ. A bimodal distribution of fibres was found, with peaks around 4 μ and 10 μ. The fibres of the low threshold main component of the compound action potential conducted at velocities between 85 and 110 m per sec. The properties of receptors and afferent fibres were studied in 52 single fibres of the median nerve. About 50 per cent of these were rapidly adapting, the others slowly adapting. Among the rapidly adapting, 33 per cent were low threshold vibration sensitive Pacinian receptors whose fibres conducted at velocities between 63 and 117m per sec. The remaining 15 per cent were identified as high threshold tap receptors, some of which were vibration sensitive. Their fibres conducted at velocities between 27 and 118 m per sec. 36 per cent of the slowly adapting units were tension receptors with fibres conducting at velocities between 27 and 110 m per sec. The other group (12 per cent) consisted of muscle spindles. They conducted at velocities between 85 and 110 m per sec. About 4 per cent of the population remained unidentified. Functional aspects of the findings are discussed.