The influence of nerve fiber distribution on the recruitment behavior resulting from intraneural stimulation

Abstract

Abstrwi -Force recruitment cumes have been recorded for the rat extensor digitorum longus muscle (EDL) using monopolar stimulation with intraneural wire electrodes. The recruitment curves vary with the position of the electrode in the nerve This has implications when intraneural stimulation techniques are used to precisely control muscle force. To assess this effect, two parameters were extracted for each recruitment cuwe: the threshold current and the slnpe in the low-farce range. When these experimental parameters are compared with the same parameters resulting from simulated recruitment curves, it becomes clear that the low density of nodes of Ranvier and the degree of clustering of nerve fibers are of major importance for the recruitment behavior resulting from intraneural stimulation. It is also shown that the external medium conductivity a, is an important parameter influencing the recruitment behavior.

Endoneural selective stimulating using wire-microelectrode arrays

“…It is obvious that endoneural selective stimulation of an arbitrary nerve fiber is best served by approaching that fiber very closely, preferably by putting an electrode in close proximity to one of its nodes of Ranvier [11], [17]. Experiments with endoneural microelectrodes support this idea, as they have shown that the recruitment behavior in the low-force range varies strongly with the position of a monopolar stimulating electrode [8], [13], [18], [19], [22]. Model simulations have confirmed this variation [8], [18].…”

Intraneural stimulation using 2D wire-microelectrode arrays. II. Comparison with single-wire electrode results

“…A similar scattergram is presented for single wireelectrode experiments [1,2], in which the nerve was immersed in Ringer's solution (Fig. l(b)).…”

“…wire-electrodes as presented in [l] and [2]. Since wire electrodes can be introduced into the nerve without making an incision first, current leakage is minimal in this case.…”

“…Each cuve was characterized by the threshold current and the slope in the low-force range [1,2]. The low-force range was defined as the range where the twitch-force maximum was between 4.9" and 147" (corresponding to the force associated with a weight of 0.5 g and 15 g, respectively).…”