Investigations of C-fos expression in rat spinal cord in vitro
Investigations of C-fos expression in rat spinal cord in vitro
We have developed an isolated preparation of rat spinal cord in which c-fos like immunoreactivity can be demonstrated in dorsal horn neurons as a specific response to high intensity dorsal root stimulation.
Rats weighing 30 - 40gm, were killed by halothane overdose and rapidly perfused transcardially with chilled Tyrode's solution prior to decapitation and removal of the spinal cord. Cords were mounted in an incubation chamber and recordings made at 27oC. Trains of electrical stimuli (0.5ms pulses, 10Hz for 10 min) were delivered to a lumbar dorsal root at an intensity of twenty times the threshold of the most excitable axons, and dorsal root activity or dorsal horn field potentials were monitored. Two hours after stimulation cords were processed for c-fos immunoreactivity and counts made of the number of dorsal horn cells expressing c-fos like activity in the lumbar cord.
These experiments demonstrated that c-fos-like immunoreactivity could be expressed in the isolated spinal cord maintained in vitro, and that expression was dependent upon small diameter afferent activation. Replacement of Ca++ by Mn++ blocked fos activity completely and the optimal temperature for c-fos expression was found to be 27oC. The expression of c-fos reach the peak 2 hours after stimulation and could be modified by changes in the incubation medium. The NMDA receptors were shown to mediate the slow dorsal horn field potential which was blocked by DAP5 could also reduce c-fos transcription. The NK1 receptor antagonist CP99994 suppressed the very slow component of the dorsal horn field potential and part of the c-fos immunoreactivity in the dorsal horn. The κ-receptor agonist dynorphin (1-17), but not the μ-receptor agonist morphine, blocked the spinal c-fos expression induced by high intensity dorsal root stimulation. This effect was reversed by the opiate antagonist naloxone.
University of Southampton
1997
Zhang, Li Ping
(1997)
Investigations of C-fos expression in rat spinal cord in vitro.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
We have developed an isolated preparation of rat spinal cord in which c-fos like immunoreactivity can be demonstrated in dorsal horn neurons as a specific response to high intensity dorsal root stimulation.
Rats weighing 30 - 40gm, were killed by halothane overdose and rapidly perfused transcardially with chilled Tyrode's solution prior to decapitation and removal of the spinal cord. Cords were mounted in an incubation chamber and recordings made at 27oC. Trains of electrical stimuli (0.5ms pulses, 10Hz for 10 min) were delivered to a lumbar dorsal root at an intensity of twenty times the threshold of the most excitable axons, and dorsal root activity or dorsal horn field potentials were monitored. Two hours after stimulation cords were processed for c-fos immunoreactivity and counts made of the number of dorsal horn cells expressing c-fos like activity in the lumbar cord.
These experiments demonstrated that c-fos-like immunoreactivity could be expressed in the isolated spinal cord maintained in vitro, and that expression was dependent upon small diameter afferent activation. Replacement of Ca++ by Mn++ blocked fos activity completely and the optimal temperature for c-fos expression was found to be 27oC. The expression of c-fos reach the peak 2 hours after stimulation and could be modified by changes in the incubation medium. The NMDA receptors were shown to mediate the slow dorsal horn field potential which was blocked by DAP5 could also reduce c-fos transcription. The NK1 receptor antagonist CP99994 suppressed the very slow component of the dorsal horn field potential and part of the c-fos immunoreactivity in the dorsal horn. The κ-receptor agonist dynorphin (1-17), but not the μ-receptor agonist morphine, blocked the spinal c-fos expression induced by high intensity dorsal root stimulation. This effect was reversed by the opiate antagonist naloxone.
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Published date: 1997
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Local EPrints ID: 463011
URI: http://eprints.soton.ac.uk/id/eprint/463011
PURE UUID: ae233fd1-9b23-4c5b-b3dd-a3d668ce1b1a
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Date deposited: 04 Jul 2022 20:37
Last modified: 04 Jul 2022 20:37
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Author:
Li Ping Zhang
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