Limits...
Effects of low level laser treatment on the survival of axotomized retinal ganglion cells in adult Hamsters.

So KF, Leung MC, Cui Q - Neural Regen Res (2014)

Bottom Line: Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate.We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy.These findings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal ganglion cells.

View Article: PubMed Central - PubMed

Affiliation: GHM Institute of CNS Regeneration, and Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, Guangdong Province, China ; Department of Anatomy, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China ; Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.

ABSTRACT
Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the first week with a short period of treatment time (5 minutes) in which 65-66% of retinal ganglion cells survived the optic nerve axotomy whereas 45-47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These findings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal ganglion cells.

No MeSH data available.


Related in: MedlinePlus

Effects of delayed laser irradiation on the survival of retinal ganglion cells (RGCs) after optic nerve axotomy.The average number of granular blue-labeled RGCs after axotomy at 7 days post-axotomy was declined with the increased time from the commencement of a 5-minute single dose laser irradiation. Laser treatment was no longer neuroprotective if the commencement of the treatment was delayed 1 hour (h) or more. Data are expressed as the mean ± SD. *P < 0.05 (one-way analysis of variance followed by Bonferroni multiple comparison test).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4281419&req=5

Figure 5: Effects of delayed laser irradiation on the survival of retinal ganglion cells (RGCs) after optic nerve axotomy.The average number of granular blue-labeled RGCs after axotomy at 7 days post-axotomy was declined with the increased time from the commencement of a 5-minute single dose laser irradiation. Laser treatment was no longer neuroprotective if the commencement of the treatment was delayed 1 hour (h) or more. Data are expressed as the mean ± SD. *P < 0.05 (one-way analysis of variance followed by Bonferroni multiple comparison test).

Mentions: We further studied the effect of delayed commencement of laser treatment. Since 5-minute laser treatment groups had the best neuropretective effect at both 7 and 14 days post-axotomy, the 5-minute laser treatment regime was selected as the optimal treatment duration for delayed treatment studies. As shown in Figure 5, the average number of GB-labeled RGCs after axotomy at 7 days post-axotomy declined with the increased time-delay of commencement of a 5-minute single dose laser irradiation. Though the 0.5 hour delay still exerted a neuroprotective action on RGCs (44,002 ± 1,203/retina, n = 4; P < 0.05; Figure 5), the average numbers of GB-labeled RGCs in 1, 3 and 12 hour delay treatment groups decreased to 40,339 ± 1,987/retina (n = 4), 36,029 ± 2,459/retina (n = 4) and 36,956 ± 1,741/retina (n = 4), respectively (Figure 5). There was no significant difference (P < 0.05) between these three delayed treatment groups and the axotomy control, or among these three groups. In other words, there will be no protective effect if 5-minute laser irradiation treatment started 1 hour after ON axotomy.


Effects of low level laser treatment on the survival of axotomized retinal ganglion cells in adult Hamsters.

So KF, Leung MC, Cui Q - Neural Regen Res (2014)

Effects of delayed laser irradiation on the survival of retinal ganglion cells (RGCs) after optic nerve axotomy.The average number of granular blue-labeled RGCs after axotomy at 7 days post-axotomy was declined with the increased time from the commencement of a 5-minute single dose laser irradiation. Laser treatment was no longer neuroprotective if the commencement of the treatment was delayed 1 hour (h) or more. Data are expressed as the mean ± SD. *P < 0.05 (one-way analysis of variance followed by Bonferroni multiple comparison test).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4281419&req=5

Figure 5: Effects of delayed laser irradiation on the survival of retinal ganglion cells (RGCs) after optic nerve axotomy.The average number of granular blue-labeled RGCs after axotomy at 7 days post-axotomy was declined with the increased time from the commencement of a 5-minute single dose laser irradiation. Laser treatment was no longer neuroprotective if the commencement of the treatment was delayed 1 hour (h) or more. Data are expressed as the mean ± SD. *P < 0.05 (one-way analysis of variance followed by Bonferroni multiple comparison test).
Mentions: We further studied the effect of delayed commencement of laser treatment. Since 5-minute laser treatment groups had the best neuropretective effect at both 7 and 14 days post-axotomy, the 5-minute laser treatment regime was selected as the optimal treatment duration for delayed treatment studies. As shown in Figure 5, the average number of GB-labeled RGCs after axotomy at 7 days post-axotomy declined with the increased time-delay of commencement of a 5-minute single dose laser irradiation. Though the 0.5 hour delay still exerted a neuroprotective action on RGCs (44,002 ± 1,203/retina, n = 4; P < 0.05; Figure 5), the average numbers of GB-labeled RGCs in 1, 3 and 12 hour delay treatment groups decreased to 40,339 ± 1,987/retina (n = 4), 36,029 ± 2,459/retina (n = 4) and 36,956 ± 1,741/retina (n = 4), respectively (Figure 5). There was no significant difference (P < 0.05) between these three delayed treatment groups and the axotomy control, or among these three groups. In other words, there will be no protective effect if 5-minute laser irradiation treatment started 1 hour after ON axotomy.

Bottom Line: Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate.We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy.These findings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal ganglion cells.

View Article: PubMed Central - PubMed

Affiliation: GHM Institute of CNS Regeneration, and Guangdong Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, Guangdong Province, China ; Department of Anatomy, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China ; Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.

ABSTRACT
Injury to axons close to the neuronal bodies in the mammalian central nervous system causes a large proportion of parenting neurons to degenerate. It is known that optic nerve transection close to the eye in rodents leads to a loss of about half of retinal ganglion cells in 1 week and about 90% in 2 weeks. Using low level laser treatment in the present study, we demonstrated that treatment with helium-neon (660 nm) laser with 15 mW power could delay retinal ganglion cell death after optic nerve axotomy in adult hamsters. The effect was most apparent in the first week with a short period of treatment time (5 minutes) in which 65-66% of retinal ganglion cells survived the optic nerve axotomy whereas 45-47% of retinal ganglion cells did so in optic nerve axotomy controls. We also found that single dose and early commencement of laser irradiation were important in protecting retinal ganglion cells following optic nerve axotomy. These findings thus convincingly show that appropriate laser treatment may be neuroprotective to retinal ganglion cells.

No MeSH data available.


Related in: MedlinePlus