The distribution of cutaneous receptors in the rabbit's hind limb and differential electrical stimulation of their axons

Abstract

SUMMARY1. The receptive field properties and conduction velocities of single dorsal root axons, activated from the sural and cutaneous branches of the posterior tibial (medial plantar) nerves, were examined in anaesthetized rabbits.2. The sural nerve sample included all types of units previously recorded from the saphenous nerve . In particular it was shown that electrical stimulation of the sural nerve at strengths up to 1-3T produced a volley of impulses in a pure population of slowly adapting units (Type I units).3. The medial plantar sample showed an absence of Type I slowly adapting units and Type T hair follicle units. Corresponding to this there were no touch corpuscles or tylotrich hairs in the skin of the hind foot and the fastest medial plantar axons conducted at 60-70 m/sec as opposed to 80-85 m/sec for the sural nerve. Stimulation of the medial plantar nerve at stimulus strengths close to threshold produced a volley of impulses in a nearly pure population of Type G hair follicle units.

Tactile sensibility in the human hand: relative and absolute densities of four types of mechanoreceptive units in glabrous skin.

“…However, there is no indication in the literature of any major differences, neither between the four types of glabrous skin units, nor between similar unit types in hairy skin. Small differences have been reported in some studies suggesting that the SA II and the PC units conduct at a slightly lower velocity than the two other types (Iggo, 1963;Brown & Iggo, 1967;Burgess, Petit & Warren, 1968;Perl, 1968;Jinig et al 1968;Talbot et al 1968;Merzenich & Harrington, 1969;Brown & Hayden, 1971;Knibest6l, 1973Knibest6l, , 1975Whitehorn, Howe, Lessler & Burgess, 1974;Pubols & Pubols, 1976;Iggo & Ogawa, 1977). However, the difference in conduction velocity would correspond to a mean difference in nerve fibre diameter of only 1-2 ,um.…”

Reliability of Cutaneous Electrical Perceptual Threshold in the Assessment of Sensory Perception in Patients with Spinal Cord Injury

“…Square wave cutaneous electrical stimulation at the threshold for sensation has also been reported as tap, flutter, or tingle with considerably higher stimulus strengths being required to cause painful sensations such as pinprick or sting (Sang et al, 2003). Additionally, it is generally appreciated (Blair and Erlanger, 1933;Brown and Hayden, 1971) that weak, electrical stimulation of cutaneous nerves is known to excite preferentially large sensory axons (Aab) that subserve non-noxious modalities of sensation. Higher strengths that cause sharp pain or persistent, burning pain have been shown to cause Ad fiber and C-fiber activation respectively (Collins et al, 1960).…”