Electrophysiological and pharmacological studies on the isolated mammalian spinal cord preparation
Electrophysiological and pharmacological studies on the isolated mammalian spinal cord preparation
The hamster isolated spinal cord maintained in Mg-free ACSF at 24-25oC survived well in vitro; and exhibits characteristic bursts of spontaneous action potentials emerging from the cord along the dorsal roots and in the dorsal horn. Stimulation of an adjacent dorsal root, leads to a volley of antidromic action potentials (DRR) recorded emerging from the dorsal roots.
The aim of the present study was to study the spinal mechanisms underlying the correlation between the spontaneous activity in two dorsal roots and the spread of the dorsal root reflex, by investigating the pathways mediating the correlation between the two dorsal roots. Spontaneous and evoked action potentials in two dorsal roots (at least two segments apart) were recorded extracellularly before (control) and after sectioning the longitudinal tract or a reversible blockade using lidocaine.
The results revealed that there is a linkage network correlating the spontaneous dorsal root activity along the spinal cord as well as the dorsal root reflex activity within the spinal cord. A good cross correlation of spontaneous activity was obtained between ipsilateral and contralateral dorsal roots, 10 and 4 segments apart respectively. An evoked dorsal root reflex was also recorded propagating for 8 segments rostrocaudally and also across the cord. Transection of the cord above and below the recording electrodes did not alter the correlation between the activity, or the pattern of spontaneous activity in both roots; similarly, when partial cuts were made on the ventral horn and dorsal horn. However, when the dorsal column only was cut the correlation was abolished as was the DRR. The spontaneous activity persisted. In contrast when the dorsal part of the dorsal column cut was cut the correlation was abolished but the DRR persisted. Cutting the dorsal column tracts between the two dorsal root segments did not affect the generation of the spontaneous activity or the number of spikes per burst. This suggests that the bursting pattern is generated locally in each segment.
University of Southampton
Al-Sagair, Othman Abdulrahman
1994
Al-Sagair, Othman Abdulrahman
Al-Sagair, Othman Abdulrahman
(1994)
Electrophysiological and pharmacological studies on the isolated mammalian spinal cord preparation.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The hamster isolated spinal cord maintained in Mg-free ACSF at 24-25oC survived well in vitro; and exhibits characteristic bursts of spontaneous action potentials emerging from the cord along the dorsal roots and in the dorsal horn. Stimulation of an adjacent dorsal root, leads to a volley of antidromic action potentials (DRR) recorded emerging from the dorsal roots.
The aim of the present study was to study the spinal mechanisms underlying the correlation between the spontaneous activity in two dorsal roots and the spread of the dorsal root reflex, by investigating the pathways mediating the correlation between the two dorsal roots. Spontaneous and evoked action potentials in two dorsal roots (at least two segments apart) were recorded extracellularly before (control) and after sectioning the longitudinal tract or a reversible blockade using lidocaine.
The results revealed that there is a linkage network correlating the spontaneous dorsal root activity along the spinal cord as well as the dorsal root reflex activity within the spinal cord. A good cross correlation of spontaneous activity was obtained between ipsilateral and contralateral dorsal roots, 10 and 4 segments apart respectively. An evoked dorsal root reflex was also recorded propagating for 8 segments rostrocaudally and also across the cord. Transection of the cord above and below the recording electrodes did not alter the correlation between the activity, or the pattern of spontaneous activity in both roots; similarly, when partial cuts were made on the ventral horn and dorsal horn. However, when the dorsal column only was cut the correlation was abolished as was the DRR. The spontaneous activity persisted. In contrast when the dorsal part of the dorsal column cut was cut the correlation was abolished but the DRR persisted. Cutting the dorsal column tracts between the two dorsal root segments did not affect the generation of the spontaneous activity or the number of spikes per burst. This suggests that the bursting pattern is generated locally in each segment.
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Published date: 1994
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Local EPrints ID: 462628
URI: http://eprints.soton.ac.uk/id/eprint/462628
PURE UUID: 871d80fc-cc42-4ac0-95d8-570089b7531a
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Date deposited: 04 Jul 2022 19:33
Last modified: 04 Jul 2022 19:33
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Author:
Othman Abdulrahman Al-Sagair
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