Integrated micro-electrodes and micro-capillaries for the study and control of neuronal activity

Hyper-reflexia and hyper-tonicity of the muscles, commonly referred to as spasticity, is a common and debilitating phenomenon in motor disorders like stroke, spinal cord injury, multiple sclerosis or severe brain trauma. This work aims to explore a possible long term and adaptable treatment route via the exploitation of standard silicon and Micro-Electro Mechanical System (MEMS) manufacturing methods to form micron scale electrode arrays formed alongside micro-capillaries with the intention of implanting these electrodes in the brain and spine for localized stimulation and sensing. The materials and sizes will be chosen to have the least possible adverse effects and it is hoped that this can provide a long term means of receiving, stimulating and control of nerve signals after trauma such as spinal cord injury or stroke.This is technically challenging and novel and would also permit for the first time a much more detailed and comprehensive study of neuronal signals with micron precision within the spine. External stimulation both electrical and pharmacological (using directed picolitre quantities of drugs), together with electrical sensing and feedback, is unique, allowing a hitherto impossible level of manipulation, understanding and thereby control, of neurological behaviour, and without the drawbacks of systemic drug treatments. Ultimately the aim of the work will be to control pain and motor responses (and smart prosthetics) using adaptable electronic and pharmacological signals.

Hyper-reflexia and hyper-tonicity of the muscles - commonly referred to as spasticity, is a common and debilitating phenomenon in motor disorders like stroke, spinal cord injury, multiple sclerosis or severe brain trauma. It is presently treated with systemic infusion of Baclofen - GABA is a potent inhibitory neurotransmitter prevalent throughout the central nervous system. Although its primary action is in the spinal cord, its uptake is weak if administered orally (25 - 100 mg/day), so intrathecal infusion (ITB) in the spinal cord is widely used (50 - 1500 ug/day). Infusion of baclofen is highly effective in reducing hyper-tonicity of the muscles; however, long term use still has ill effects. This work will exploit standard Micro-Electro Mechanical System (MEMS) processing to form micron scale electrode arrays embedded alongside micro-capillaries with the lowest possible cross-section profile for localized stimulation and sensing in nerves. This is technically challenging and novel and would also permit for the first time a much more detailed and comprehensive study of neuronal interactions and their modulation with a precision at the micron-scale within the spine. Highly localised stimulation both electrical and pharmacological (using directed picolitre quantities of neurotransmitters or their agonist and antagonists), together with electrical sensing both near and far, is unique, allowing a hitherto impossible level of manipulation, understanding and thereby control, of neurological behaviour, and without the drawbacks of systemic or even intrathecal drug treatments. Ultimately the work will be aimed at external control of pain and motor responses using adaptable electronic and pharmacological signals.

Summary of Impact activities:

The milestones and milestone description along with target date and Impact funding requested is given below*

M1 - Engage with public at the University of Leeds and outside (All laboratory members, throughout project, no specific funding requested)

M2 - Bring in summer (high school) and under-graduate students in order to give students the chance to explore the new technologies in use (at 6 months, no specific funding requested)

M3 - Development and maintenance of project website to disseminate and present the progress of the project to both the scientific community and general public (established by month 3, and updated throughout the lifetime of the project, £1000 funding requested)

M4 - Talks at local Café Scientifique to present our findings (Year 1, no specific funding requested)

M5 - Dissemination of project results by publishing and presenting at conferences and in high impact journals, and on the project and university websites (Year 1, no specific funding requested)

M6 - Introduce a new seminar series to discuss miniaturised medical devices for medical purposes to introduce the hypothesis and early findings (Year 1, £6,000 funding requested)

M7 - Present data at SFN 2014 to disseminate project findings (Year 2, no specific funding requested)