Management of glaucoma with neuroprotective drug

Glaucoma is an optic neuropathy characterized by progressive loss of retinal ganglion cells (RGCs). Death of ganglion cells is not always only pressure dependent mechanism but also have several pressure independent mechanism that establish a cascade of changes that ultimately leads to cell death. Neuro- protection is a process that attempt to preserve the cells that were spared during initial insult, but are still vulnerable to damage. Although not yet available, a neuroprotective agent would be great use that rescue neurons already compromised or that promote regrowth of axonal or dendritic connection to restore function. This review based on literature, giving the idea of varies mechanism of RGC death delineated by research and discussed some pharmacological agent believed to have a neuroprotective role in glaucoma. DOI: 10.3329/bjms.v9i4.6685Bangladesh Journal of Medical Science Vol.09 No.4 July 2010 pp.199-203

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Involvement of glycinergic neurons in the diminished surround activity of ganglion cells in the dark-adapted rabbit retina

Visual Neuroscience ◽

10.1017/s0952523800000894 ◽

1991 ◽

Vol 6 (1) ◽

pp. 43-53 ◽

Cited By ~ 24

Author(s):

Ralph J. Jensen

Keyword(s):

Retinal Ganglion Cells ◽

Dopaminergic Neurons ◽

Dark Adaptation ◽

Ganglion Cells ◽

Dopamine Antagonist ◽

Intracellular Camp ◽

Rabbit Retina ◽

Retinal Ganglion ◽

Camp Levels ◽

Dependent Mechanism

AbstractPrevious studies have reported that the surround responses of retinal ganglion cells weaken or disappear upon dark adaptation. The mechanism(s) by which this occurs is largely unknown, although changes in activity of retinal dopaminergic neurons have been implicated. In the light-adapted rabbit retina, the surround ON responses of OFF-center ganglion cells have been shown to be markedly reduced or abolished by a dopamine antagonist. This effect of a dopamine antagonist was recently shown to be reversed by the glycine antagonist strychnine and by compounds that elevate intracellular cAMP levels. The present study was conducted to determine whether strychnine and cAMP-elevating compounds could bring out the surround ON responses in OFF-center ganglion cells that are diminished upon dark adaptation. Extracellular recordings of OFF-center brisk ganglion cells were made from isolated, superfused retinal preparations. During the course of dark adaptation, the surround On responses of many cells decreased markedly.Application in both brisk-transient and brisk-sustained OFF-center ganglion cells. The center OFF responses of these cells, on the other hand, were not enhanced by strychnine. Of the cAMP-elevating compounds tested, 8-(4-chlorophenylthio) cyclic AMP was the most effective in bringing out the surround ON responses in dark-adapted OFF-center ganglion cells. The findings from this study suggest that under dark-adapted conditions glycinergic neurons inhibit the surround component of OFF-center ganglion cells. The release of glycine from these neurons is suggested to be regulated by a cAMP-dependent mechanism.

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