Action-potential-encoded second-harmonic generation as an ultrafast local probe for nonintrusive membrane diagnostics

Humans at the dawn of the in-body electrical nerve stimulation era

Background

The neuroprosthesis laparoscopic implantation technique for electric pelvic nerve stimulation was introduced to gynaecology over 15 years ago to treat intractable pelvic neuropathic pain. Following this first indication, other applications were developed, particularly in parapleology. The LION procedure developed to assist patients with paraplegia and common problems associated with inertia when confined to a wheelchair could find revolutionary applications in aging medicine and prevention.

Materials and Methods

Spinal cord injured patients who have undergone the Possover's LION procedure.

Main outcome measure

PubMed was systematically searched to identify peer-reviewed articles published in English that reported on LION procedure.

Results

Three independent studies published recently (100 patients worldwide) have shown revolutionary recovery of supra-spinal control in patients with chronic spinal cord injury following pelvic nerves stimulation, with 70% of them establishing a walker/crutches-assisted gait. The same studies have also shown significant whole-body muscle-mass building, peripheral vasodilatation, and an unexpected improvement in bone mineral density.

Conclusion

These ground-breaking findings could find revolutionary applications in aging medicine and the prevention of osteoporosis, with a huge impact on global public health. Humanity is on the cusp of an exciting new era following the introduction of the in-body electrical nerve stimulation technique.

What is new?

In-body electrical nerve stimulation for recovery and/or control of human peripheral somatic and autonomic nervous systems.

Does low-frequency pelvic nerves stimulation in people with spinal cord injury allow for the formation of electrical pathways responsible for the recovery of walking functions?

Over the last ten years, we have published various manuscripts on the recovery of assisted voluntary walking in people with chronic spinal chord injuries (SCI), following laparoscopic implantation of stimulation electrodes on the pelvic somatic nerves - the LION procedure. Although at the beginning of this research the objective was to allow "robotic" walking by stimulating the muscles, we realized relatively quickly that continuous low frequency stimulation of the pelvic nerves might allow the recovery of voluntary functions of the lower limbs and of the trunk necessary for walking: Seventeen out of a total of twenty-five complete motor chronic SCI-patients (68%) developed enough recovery of supra-spinal control of leg movements, that voluntary walking became feasible, even though a minimal amount of stimulation may be required. All current theories for recovery these voluntary functions below the spinal cord lesion are based on the induced regrowth or reconnection of nerves or at least the recovery of functional anatomical pathways. In this manuscript we formulate the hypothesis that electrical stimulation could be responsible for inducing the formation of "electrical pathways" within the body, which under conditions of electrical stimulation might enable the transport of necessary information from the brain to below the spinal cord lesion allowing voluntary movements of the lower limbs.

Initiation and blocking of the action potential in an axon in weak ultrasonic or microwave fields

In this paper, we analyze the effect of the redistribution of the transmembrane ion channels in an axon caused by longitudinal acoustic vibrations of the membrane. These oscillations can be excited by an external source of ultrasound and weak microwave radiation interacting with the charges sitting on the surface of the lipid membrane. It is shown, using the Hodgkin-Huxley model of the axon, that the density redistribution of transmembrane sodium channels may reduce the threshold of the action potential, up to its spontaneous initiation. At the significant redistribution of sodium channels in the membrane, the rarefaction zones of the transmembrane channel density are formed, blocking the propagation of the action potential. Blocking the action potential propagation along the axon is shown to cause anesthesia in the example case of a squid axon. Various approaches to experimental observation of the effects considered in this paper are discussed.