Juanita J. Anders

Phototherapy promotes regeneration and functional recovery of injured peripheral nerve.

Abstract Numerous attempts have been made to enhance and/or accelerate the recovery of injured peripheral nerves. One of the methods studied is the use of phototherapy (low power laser or light irradiation) to enhance recovery of the injured peripheral nerve. A critical analysis of the literature on the employment of phototherapy for the enhancement of the regeneration process of the rat facial and sciatic nerve (after crush injury or transection followed by surgical reconstruction) is provided, together with the description of some of the most suitable basic biological mechanisms through which laser radiation exerts its action on peripheral nerve regeneration.

New method of purification for establishing primary cultures of ensheathing cells from the adult olfactory bulb

Ensheathing cells exclusively enfold olfactory axons. The ability of olfactory axons to reinnervate the adult mammalian olfactory bulb throughout the lifetime of an organism is believed to result from the presence of this unique glial cell in the olfactory system. This theory has been substantiated by research demonstrating the ability of transplanted ensheathing cells to promote axonal regrowth in areas of the central nervous system that are normally nonpermissive. A simple method for purifying ensheathing cells resulting in a large yield of cells is therefore invaluable for transplantation studies. We have developed such a method based on the differing rates of attachment of the various harvested cell types. The greatest percentage of cells (70.4%) that attached during the first step of the separation was determined to be fibroblasts. The remainder of the cells were classified as astrocytes (20.8%) and ensheathing cells (6.8%). The percentage of attached astrocytes (67.6%) was greatly increased during the second purification step while the percentage of fibroblasts decreased greatly (27.9%) and the percentage of ensheathing cells (5.3%) slightly decreased. In the final cultures, 93.2 % of the attached cells were ensheathing cells, while astrocytes (5.9%) and fibroblasts (1.4%) were only minor components. This simple, inexpensive method of purifying ensheathing cells will facilitate their use in central nervous system regeneration research. GLIA 34:81–87, 2001.

810 nm Wavelength light: An effective therapy for transected or contused rat spinal cord

Light therapy has biomodulatory effects on central and peripheral nervous tissue. Spinal cord injury (SCI) is a severe central nervous system trauma with no effective restorative therapies. The effectiveness of light therapy on SCI caused by different types of trauma was determined.

Single-cell printing to form three-dimensional lines of olfactory ensheathing cells

Biological laser printing (BioLP) is a unique tool capable of printing high resolution two- and three-dimensional patterns of living mammalian cells, with greater than 95% viability. These results have been extended to primary cultured olfactory ensheathing cells (OECs), harvested from adult Sprague-Dawley rats. OECs have been found to provide stimulating environments for neurite outgrowth in spinal cord injury models. BioLP is unique in that small load volumes ( approximately microLs) are required to achieve printing, enabling low numbers of OECs to be harvested, concentrated and printed. BioLP was used to form several 8 mm lines of OECs throughout a multilayer hydrogel scaffold. The line width was as low as 20 microm, with most lines comprising aligned single cells. Fluorescent confocal microscopy was used to determine the functionality of the printed OECs, to monitor interactions between printed OECs, and to determine the extent of cell migration throughout the 3D scaffold. High-resolution printing of low cell count, harvested OECs is an important advancement for in vitro study of cell interactions and functionality. In addition, these cell-printed scaffolds may provide an alternative for spinal cord repair studies, as the single-cell patterns formed here are on relevant size scales for neurite outgrowth.

Quantitative analysis of transcranial and intraparenchymal light penetration in human cadaver brain tissue.

Photobiomodulation (PBM) also known as low‐level light therapy has been used successfully for the treatment of injury and disease of the nervous system. The use of PBM to treat injury and diseases of the brain requires an in‐depth understanding of light propagation through tissues including scalp, skull, meninges, and brain. This study investigated the light penetration gradients in the human cadaver brain using a Transcranial Laser System with a 30 mm diameter beam of 808 nm wavelength light. In addition, the wavelength‐dependence of light scatter and absorbance in intraparenchymal brain tissue using 660, 808, and 940 nm wavelengths was investigated. in vivo. Lasers Surg. Med. 47:312–322, 2015.

Dual-confocal fiber-optic method for absolute measurement of refractive index and thickness of optically transparent media

We present a novel noncontact optical method for absolute measurement of refractive index and thickness of optically transparent media. The method is based on a simple dual-confocal fiber-optic sensor design. It includes two independent confocal channels consisting of two identical apertureless fiber-optic-type confocal microscopes constructed by use of a single 2x2 fiber coupler. A geometrical-ray model is used to obtain the analytical dependence between the samples refractive index and its thickness. The measurement method provides high accuracy in spatially locating the specific imaging points that correspond to the backreflected intensity peaks of the confocal responses. Thus, a simultaneous measurement of the sample refractive index and thickness is achieved.

In vitro and in vivo optimization of infrared laser treatment for injured peripheral nerves.

Repair of peripheral nerve injuries remains a major challenge in restorative medicine. Effective therapies that can be used in conjunction with surgical nerve repair to improve nerve regeneration and functional recovery are being actively investigated. It has been demonstrated by a number of peer reviewed publications that photobiomodulation (PBM) supports nerve regeneration, reinnervation of the denervated muscle, and functional recovery after peripheral nerve injury. However, a key issue in the use of PBM as a treatment for peripheral nerve injury is the lack of parameter optimization for any given wavelength. The objective of this study was to demonstrate that for a selected wavelength effective in vitro dosing parameters could be translated to effective in vivo parameters.

Light Supports Neurite Outgrowth of Human Neural Progenitor Cells In Vitro : The Role of P2Y Receptors

The purpose of this study was to compare the effects of growth factors and 810-nm-wavelength light on the differentiation of normal human neural progenitor cells (NHNPCs) in vitro. Although growth factors are routinely used to study neural stem and progenitor cells in vitro, to date, light has not been used as a replacement for growth factors. This study demonstrates that NHNPCs are not only capable of being sustained by light in the absence of growth factors, but that they are also able to differentiate normally as assessed by neurite formation. The NHNPCs had an up-regulation in the expression of endogenous fibroblast growth factor-2, brain derived neurotrophic factor, and nerve growth factor in response to the light. Suramin, a nonselective P2 receptor antagonist, significantly decreased neurite outgrowth, and P2Y2 and P2Y11 receptors were found to be expressed by the NHNPCs by immunolabeling. Based on these findings, the mechanism by which light supports the NHNPC differentiation is hypothesized to be due to increases in adenosine triphosphate acting via P2Y receptors.

Light therapy and supplementary Riboflavin in the SOD1 transgenic mouse model of familial amyotrophic lateral sclerosis (FALS).

Familial amyotrophic lateral sclerosis (FALS) is a neurodegenerative disease characterized by progressive loss of motor neurons and death. Mitochondrial dysfunction and oxidative stress play an important role in motor neuron loss in ALS. Light therapy (LT) has biomodulatory effects on mitochondria. Riboflavin improves energy efficiency in mitochondria and reduces oxidative injury. The purpose of this study was to examine the synergistic effect of LT and riboflavin on the survival of motor neurons in a mouse model of FALS.

Meningeal cells increase in vitro astrocytic gap junctional communication as measured by fluorescence recovery after laser photobleaching.

SummaryThe presence of meningeal cells is necessary for the normal development of the glia limitans. Astrocytes comprising the adult glia limitans have several unique features, including many more gap junctions than is typical for astrocytes in the underlying molecular layer. This study examines the possible influence of meningeal cells on the establishment and maintenance of specific characteristics of astrocytes in the glia limitans. Primary cultures of rat astrocytes and meningeal cells were used to examine whether meningeal cells could alter astrocytic gap junctional dye coupling. Astrocytes and meningeal cells were grown on separate glass slides and co-cultured by forming a sandwich with the slides. The sides of the slides containing the cells faced each other and were separated by a 1 mm thick gasket along the edge of the slides. Although the meningeal cells and astrocytes were bathed in the same medium, they were separated by a distance of 1 mm and were not in direct contact during the co-culture period. The cells were co-cultured for 24, 48 or 72 hours, and astrocytic gap junctional dye coupling was examined using the gap-FRAP technique. The mean total recovery of fluorescence for control astrocytes was 14%. Astrocytes co-cultured with meningeal cells for 24 hours did not show a significant difference in the fluorescence recovery when compared to the control values. After 48 hours of co-culture, there was a significant increase in the gap junctional dye coupling. After 72 hours, gap junctional dye coupling continued to increase (total fluorescence recovery=53%). These results indicate that meningeal cells can influencein vitro gap junctional coupling. It is speculated that the prevalence of gap junctions in the glia limitans is due to-the meningeal-glial interaction.