Excitation and Suppression

Since its inception, the commercial neurostimulation industry has relied primarily on activation of neural signals to achieve the desired result. As Warren Grill points out in his article on page 1 of this issue, suppression of neural signals may prove to be an equally powerful tool for neurotechnology firms.

The presence of two opposing and complementary modes of stimulation in the neural engineer’s arsenal promises to deliver altogether new capabilities to manufacturers of neurostimulation devices. It is particularly appropriate in neuromodulation applications, such as treatment of chronic pain, urinary incontinence, and tinnitus (see article, page 1), where spurious neural signals may be at the root of the problem.

Once neurostimulation products with both excitation and suppression capabilities are on the market, clinicians such as neurologists, urologists, and physiatrists will have much more flexibility in designing and prescribing treatment regimens. To accommodate this flexibility, new devices will need to incorporate more sophisticated programmers that can control and sequence different waveforms and stimulation modalities.

This development highlights the importance of continued advances in our understanding of nervous system function at the systems level. The more success that neurophysiologists have in mapping the functional connections between brain centers, nuclei, and individual nerve fibers, the greater capabilities neurotechnologists will have in addressing dysfunctional connections. A good example of this is NeuroSystec’s exploitation of identifying the NMDA receptors in the spiral ganglion as playing a role in the onset of tinnitus. In general, neurotechnology approaches to treating neurological diseases and disorders will fare better, in relation to bio/pharma approaches, when greater specificity and localization of treatment is called for.

Perhaps there is a metaphoric value to the presence of both excitatory and inhibitory signaling in the nervous system and that is in the way that vendors provide information to investors, clinicians, and the public. Just as neurotech treatments that rely only on excitatory stimulation are more limited than those that include excitation and suppression, so too are neurotech vendors limited by corporate communications efforts that consistently report only positive results of research and clinical trials. Neurotechnology approaches are not appropriate for treating every medical condition and vendors who report research that favors a different treatment modality do the industry a favor. This not only brings more credibility in the eyes of the outside world, it also gives investors and boards more specific information they can use to monitor progress toward existing milestones and help determine of new ones

James Cavuoto
Editor and Publisher