Intraspinal microstimulation for respiratory muscle activation.

Intraspinal microstimulation for respiratory muscle activation. Exp Neurol. 2018 Jan 02;: Authors: Sunshine MD, Ganji CN, Reier PJ, Fuller DD, Moritz CT Abstract A complex propriospinal network is synaptically coupled to phrenic and intercostal motoneurons, and this makes it difficult to predict how gray matter intraspinal microstimulation (ISMS) will recruit respiratory motor units. We therefore mapped the cervical and high thoracic gray matter at locations which ISMS activates diaphragm (DIA) and external intercostal (EIC) motor units. Respiratory muscle electromyography (EMG) was recorded in anesthetized female spinally intact adult rats while a stimulating electrode was advanced ventrally into the spinal cord in 600μm increments. At each depth, single biphasic stimuli were delivered at 10-90μA during both the inspiratory and expiratory phase independently. Twenty electrode tracks were made from C2-T1 at medial and lateral gray matter locations. During inspiration, ISMS evoked DIA and EIC activity throughout C2-T1 gray matter locations, with mutual activation occurring at 17±9% of sites. During inspiratory phase ISMS the average latency for DIA activation was 4.40±0.70ms. During the expiratory phase, ISMS-induced DIA activation required electrodes to be in close proximity to the phrenic motoneuron pool, and average activation latency was 3.30±0.50ms. We conclude that appropriately targeted ISMS can co-activate DIA and EIC mot...
Source: Experimental Neurology - Category: Neurology Authors: Tags: Exp Neurol Source Type: research