| || |
|Title:||A WIRELESSLY CONTROLLED AND POWERED IMPLANTABLE NERVE STIMULATION AND RECORDING DEVICE FOR MICE|
| || |
|Authors/Affiliations:||1 Thomas Harrison*; 1 Paul Leslie; 1 Carl Spani; 1 Bernie Till; 1 Nigel Livingston; 1 Kerry Delaney; |
1 University of Victoria, BC, Canada
| || |
|Content:||Objectives: Rettâ™s syndrome is a developmental disorder characterized by the predictable time course of its symptoms. This is true both in humans and in MeCP2-null mice, a genetic model of Rettâ€™s syndrome. In mice, symptom onset is at 4-5 weeks of age, leading to death usually from 8-11 weeks in the Jaenisch mouse model we use. We hypothesize that vagus nerve stimulation applied pre-symptomatically could improve the developmental phenotype of these mice by increasing neuromodulatory input and normalizing autonomic function. This experiment requires the design and manufacture of a novel nerve stimulation and recording device suitable for implantation in juvenile mice.|
Material and Methods: Miniaturization of this device was achieved in part by removing a battery from the implantation package and powering the circuitry inductively from a 2.8mHz electromagnetic field generated in the base of the home cage. The device has a 2.4 MHz two-way radio and microprocessor permitting real-time monitoring with 5 kHz sampling of electrophysiological signals and allowing stimulus parameters to be reconfigured at any time. The circuitry draws less than 4.5mA in operation. The implant has dimensions of approximately 10mm x 7mm x 5mm and a mass of 0.6 grams prior to encapsulation in silicone elastomer for sub-cutaneous implantation.
Results: The device is capable of nerve stimulation using a tripolar cuff electrode to generate uni-directionally propagating action potentials at frequencies in excess of 100Hz. Onboard circuitry provides the amplification and filtering required to record high-quality single unit, EEG, ECG, EMG, or ENG data.
Conclusions: This device is suitable for long-term experiments in mice involving stimulation and/or electrophysiological recording. Potential applications include: monitoring of neural activity during progression of postnatal developmental disorders, recovery from stroke, chronic studies of brain, nerve, or muscle stimulation, monitoring drug treatment effects, or functional electrical stimulation for neuroprosthetic devices.
This work was supported by a CIHR High Risk Seed Grant, First Episodes in Early Childhood Program and CanAssist UVic.
| || |