532 nm Low-Power Laser Irradiation Facilitates the Migration of GABAergic Neural Stem/Progenitor Cells in Mouse Neocortex

Abstract

Background and ObjectiveAccumulating evidence has shown that low-power laser irradiation (LLI) affects cell proliferation and survival, but little is known about LLI effects on neural stem/progenitor cells (NSPCs). Here we investigate whether transcranial 532 nm LLI affects NSPCs in adult murine neocortex and in neurospheres from embryonic mice.Study Design/Materials and MethodsWe applied 532 nm LLI (Nd:YVO4, CW, 60 mW) on neocortical surface via cranium in adult mice and on cultured cells from embryonic mouse brains in vitro to investigate the proliferation and migration of NSPCs and Akt expression using immunohistochemical assays and Western blotting techniques.ResultsIn vivo experiments demonstrated that 532 nm LLI significantly facilitated the migration of GABAergic NSPCs that were induced to proliferate in layer 1 by mild ischemia. In vitro experiments using GABAergic NSPCs derived from embryonic day 14 ganglionic eminence demonstrated that 532 nm LLI for 60 min promoted the migration of GAD67-immunopositive NSPCs with a significant increase of Akt expression. Meanwhile, the LLI induced proliferation, but not migration, of NSPCs that give rise to excitatory neurons.ConclusionIt is concluded that 532 nm LLI promoted the migration of GABAergic NSPCs into deeper layers of the neocortex in vivo by elevating Akt expression.

New Neurons in the Post-ischemic and Injured Brain: Migrating or Resident?

“…Although this approach facilitated the estimation of the proliferation and differentiation of NPCs, it provided only indirect evidence of neuroblast migration. The signs of migration can be: a distribution pattern of migrating neuroblasts (markers – DCX and sometimes PSA-NCAM) from the place of origin toward the place of destination (Palma-Tortosa et al, 2017), a density gradient of neuroblasts with high density at the presumed place of origin (Thored et al, 2006; Fukuzaki et al, 2015), as well as the change in this gradient at subsequent time points (Yan et al, 2007; Oya et al, 2009; Li et al, 2011). Also, in their works researchers pay due attention to the orientation of migrating cells.…”

“…At the same time, some studies do in fact suggest that the production of new neurons can occur in the injured cortex (Gu et al, 2000; Kuge et al, 2009; Ohira et al, 2010; Shimada et al, 2010, 2012; Bi et al, 2011; Nakagomi et al, 2011, 2015; Fukuzaki et al, 2015). Bi et al (2011) showed by special labeling that, after neonatal hypoxia, cortex astrocytes in neonates gain the properties of NSCs and differentiate into new neurons both in the damaged cortex and after having been translated into cell culture.…”

“…Fukuzaki et al (2015) described in their work that after 10-min cross-clamping of the two carotid arteries they observed proliferation of GAD67-positive NPCs in the cortex. The fact that these cells localized mainly in the first layer showed that they were local precursors.…”

Brain Photobiomodulation Therapy: a Narrative Review

“…Moreover, notable enhancements in brain functions have been achieved using 1064 nm Nd:YAG laser light which has high penetration ability through the skull [210,202]. Increases in neuronal proliferation and ATP production have been found following green laser irradiation (532 nm) [215,216], and promotion of differentiation and proliferation of stem cells following irradiation with blue LED (420 nm) and green light (540 nm) [217] have been also shown. The activation of transducing cellular signals through the several intermediates following the absorption of blue and green light by cryptochromes and opsin photoreceptors, respectively, has been explained as mechanism involved in photostimulatory effects of this range of wavelengths (Fig.…”

Photobiomodulation effect of red LED (630 nm) on the free radical levels produced by pulp cells under stress conditions

“…Different modalities of photobiomodulation have been employed as adjuvant treatments for bone loss, myalgia, skin burns, spinal cord injury, and pulp repair [6][7][8][9][10]. Clinical and laboratory studi es have evaluat ed the eff ect of photobiomodulation on the healing of different tissues, such as the muscle and cartilage [11,12], neuronal cells [13,14], bone [15,16], and the dentin-pulp complex [2,17,18].…”