Retinal ganglion cell response to axotomy and nerve growth factor antiserum in the regenerating visual system of the newt (Notophthalmus viridescens): an ultrastructural morphometric analysis.
One 3.0 mg dose of the nerve growth factor antiserum (anti-NGF) injected into the vitreous chamber of the eye at the time of optic nerve transection elicits significant changes in the normal newt (Notophthalmus viridescens) retinal ganglion cell body response to axotomy at 7 and 14 days postaxotomy (DPA). Light microscopic observations indicate that anti-NGF treatment significantly reduces the per cent of retinal ganglion cells demonstrating nuclear chromatin reactivity (ie., homogeneous to a more heterogeneous state) from 33.36 +/- 3.02 to 22.82 +/- 2.98%. In addition, the per cent of retinal ganglion cells demonstrating prominent nucleoli is dramatically decreased from 32.08 +/- 1.64 to 18.20 +/- 1.79% at 7 DPA. It is also important to note that the number of prominent nucleoli in the 7 DPA group is reduced to such an extent by anti-NGF treatment that the value is not significantly different from that of intact controls. Intact controls will routinely exhibit approximately half the number of prominent nucleoli that are normal for the untreated 7 DPA group. A definite dose-response relationship can be shown to exist between the per cent of nuclear reactive ganglion cells demonstrating prominent nucleoli and various anti-NGF concentrations at 14 DPA. There does not appear to be a dose-response relationship between various anti-NGF concentrations and the per cent of retinal ganglion cells demonstrating nuclear reactivity at 14 DPA. However, the degree of nuclear chromatin reactivity appears to be less at the higher anti-NGF concentrations (ie., greater than or equal to 3.0 mg/eye) at 14 DPA. Electron microscopic morphometric analysis reveals that anti-NGF treatment significantly reduces the cell perikaryal area at 7 and 14 DPA while the nuclear area remains unchanged. Therefore, there is a significant decrease in the cytoplasmic/nuclear ratios at both 7 and 14 DPA in response to anti-NGF treatment which appears more pronounced by 14 DPA. Anti-NGF treatment also significantly reduces the mitochondrial and nucleolar densities, as well as the nucleolar areas of cells at 7 and 14 DPA. There are no significant changes in Golgi field densities in response to anti-NGF treatment.
D000818:Animals; D001369:Axons / Q000187:drug effects* / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D007106:Immune Sera / Q000494:pharmacology*; D009414:Nerve Growth Factors / Q000276:immunology*; D009416:Nerve Regeneration / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects / Q000648:ultrastructure; D009900:Optic Nerve / Q000033:anatomy & histology / Q000187:drug effects; D012160:Retina / Q000033:anatomy & histology / Q000187:drug effects*; D012455:Salamandridae
D007106:Immune Sera; D009414:Nerve Growth Factors