Abstract
BackgroundPrevious studies have shown that neurons of the cerebral cortex can be injured by implantation of, and stimulation with, implanted microelectrodes. ObjectivesObjective 1 was to determine parameters of microstimulation delivered through multisite intracortical microelectrode arrays that will activate neurons of the feline cerebral cortex without causing loss of neurons. Objective2 was to determine if the stimulus parameters that induced loss of cortical neurons differed for all cortical neurons vs. the subset of inhibitory neurons expressing parvalbumin. MethodsThe intracortical microstimulation was applied for 7 h/day for 20 days (140 h). Microelectrode site areas were 2000 and 4000 μm2, Q was 2–8 nanocoulombs (nC) at 50 Hz, and QD was 50–400 μcoulombs/cm2. ResultsNeuron loss due to stimulation was minimal at Q = 2 Ncp, but at 8 Ncp, 20%–50% of neurons within 250 μm of the stimulated microelectrodes were lost, compared to unstimulated microelectrodes. Loss was greatest in tissue facing electrode sites. Stimulation-induced loss was similar for neurons labeled for NeuN and for inhibitory neurons expressing parvalbumin. Correlation between neuron loss and QD was not significant.Electrodes in the medullary pyramidal tract recorded neuronal activity evoked by stimulation in the cerebral cortex. The pyramidal neurons were activated by intracortical stimulation of 2 nC/phase. 140 h of microstimulation at 2 nC/phase and 50 Hz induced minimal neuron loss.
Highlights
1 was to determine parameters of microstimulation delivered through multisite intracortical microelectrode arrays that will activate neurons of the feline cerebral cortex without causing loss of neurons
2 was to determine if the stimulus parameters that induced loss of cortical neurons differed for all cortical neurons vs. the subset of inhibitory neurons expressing parvalbumin
The procedures for implanting the intracortical arrays and for the animal's care were approved by the Huntington Medical Research Institutes' Institutional Animal Care and Use Committee (IACUC) in accordance with the National Institutes of Health Guide to the Care and Use of Animals
Summary
Objective 1 was to determine parameters of microstimulation delivered through multisite intracortical microelectrode arrays that will activate neurons of the feline cerebral cortex without causing loss of neurons. The size of that correspondence provides an indication of the extent to which findings for all cortical neurons can be generalized to neurons which serve various functions. Microstimulation in the sensorimotor cortex could provide sensory and proprioceptive feedback for closed-loop control of prosthetic limbs [2,5,6]. Previous studies have shown that neurons of the cerebral cortex can be injured by implantation of, and stimulation with, implanted microelectrodes. Objectives: Objective 1 was to determine parameters of microstimulation delivered through multisite intracortical microelectrode arrays that will activate neurons of the feline cerebral cortex without causing loss of neurons. Microelectrode site areas were 2000 and 4000 mm, Q was 2e8 nanocoulombs (nC) at 50 Hz, and QD was 50 e400 mcoulombs/cm
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
