» Articles » PMID: 9007541

Changes of Intracellular Free Calcium Following Mechanical Injury in a Spinal Cord Slice Preparation

Overview
Journal Exp Brain Res
Specialty Neurology
Date 1996 Dec 1
PMID 9007541
Citations 2
Authors
Affiliations
Soon will be listed here.
Abstract

Intracellular calcium ions are, in addition to free radicals, an important mediator of tissue destruction following traumatic injury to the spinal cord. In vivo measurements of calcium in the interstitial space and in the tissue suggest the occurrence of a posttraumatic shift of calcium from the extracellular to the intracellular compartment at the injury site. No information is, however, available on the posttraumatic changes of calcium in the intracellular compartment, where the ion exerts its crucial messenger function. We developed an in vitro model of local traumatic spinal injury, using a spinal cord slice preparation, allowing us to investigate injury-related changes of intracellular free calcium. The injury consisted of the impact of a small needle, and intracellular free calcium was measured with fura-2. Application of the injury at different places within the gray matter caused a transient and reproducible increase in the fura-2 fluorescence ratio. This injury-induced ratio increase was largely, but not completely, suppressed under zero extracellular calcium conditions. It was also largely depressed in the presence of high extracellular potassium and in the absence of extracellular sodium. It was modestly depressed by the calcium channel blocker nifedipin, by the calcium release channel blocker dantrolene, and by the gap junction blockers halothane and octanol. The calcium channel blocker flunarizine, the N-methyl D-aspartate (NMDA)-receptor-channel blocker MK-801 and the endoplasmic reticulum calcium-ATPase blocker thapsigargin had no effect. The experiments suggest that injury is associated with an increase in intracellular free calcium that is mediated by calcium influx, in part via L-type calcium channels. They furthermore give evidence that sodium influx and gap junctions are involved in these injury-associated changes of intracellular free calcium.

Citing Articles

Diffuse traumatic axonal injury in the optic nerve does not elicit retinal ganglion cell loss.

Wang J, Fox M, Povlishock J J Neuropathol Exp Neurol. 2013; 72(8):768-81.

PMID: 23860030 PMC: 3753119. DOI: 10.1097/NEN.0b013e31829d8d9d.


Thoracolumbar burst fractures without neurological deficit: the role for conservative treatment.

Rajasekaran S Eur Spine J. 2009; 19 Suppl 1:S40-7.

PMID: 19669803 PMC: 2899715. DOI: 10.1007/s00586-009-1122-6.

References
1.
Usachev Y, Shmigol A, Pronchuk N, Kostyuk P, Verkhratsky A . Caffeine-induced calcium release from internal stores in cultured rat sensory neurons. Neuroscience. 1993; 57(3):845-59. DOI: 10.1016/0306-4522(93)90029-f. View

2.
De Ley G, Leybaert L . Effect of flunarizine and methylprednisolone on functional recovery after experimental spinal injury. J Neurotrauma. 1993; 10(1):25-35. DOI: 10.1089/neu.1993.10.25. View

3.
Leybaert L, De Ley G . Interstitial and tissue cations and electrical potential after experimental spinal cord injury. Exp Brain Res. 1994; 100(3):369-75. DOI: 10.1007/BF02738397. View

4.
Marcotte G, Millard P, Fewtrell C . Release of calcium from intracellular stores in rat basophilic leukemia cells monitored with the fluorescent probe chlortetracycline. J Cell Physiol. 1990; 142(1):78-88. DOI: 10.1002/jcp.1041420111. View

5.
Leibowitz D . The glial spike theory. I. On an active role of neuroglia in spreading depression and migraine. Proc Biol Sci. 1992; 250(1329):287-95. DOI: 10.1098/rspb.1992.0161. View