Dynamics of ultrastructural alterations in photosensitized crayfish glial and neuronal cells: Structures involved in transport processes and neuroglial interactions

Abstract

Photodynamic therapy (PDT) is used for cancer treatment, including brain tumors. To explore the dynamics of photodynamic injury of glial cells and neurons and corresponding neuroglial interactions, we studied ultrastructure of the PDT-treated crayfish stretch receptor that consists of a single sensory neuron enwrapped by glial cells. Just after PDT, swelling of some mitochondria, dictyosomes, and endoplasmic reticulum cisterns occurred in neurons and glial cells. Tubular lattices involved in intraglial transport became swollen and disintegrated. At 1 hr postirradiation, these alterations were expanded to the whole cells. Segregation of the neuronal cytoplasm by Nissl bodies, which were involved in protein synthesis and transport along neurites, was lost. Swelling of submembrane cisterns prevented formation of glial protrusions and double-wall vesicles involved in the glia-to-neuron transport. Five hours later, glial layers lost organelles, stuck together, or dilated locally as a result of edema. In the neuronal cytoplasm, only demises of ER and swollen mitochondria were present, but few mitochondria retained normal structure. Thus, swelling of intracellular organelles, the first sign of photodynamic injury, occurred simultaneously in neurons and glia, but glial organelles were eliminated more quickly. Therefore, glial cells were less resistant to PDT than neurons. Adjacent glial layers were damaged less than remote ones, suggesting their protection by the neuron. The structures involved in glia-to-neuron (neuronal submembrane cisterns, glial protrusions, double-wall vesicles), intraglial (tubular lattices), and intraneuronal (Nissl bodies, Golgi apparatus, microtubular bundles) transport were impaired at the earlier stages of stretch receptor damage.

Neuroprotective response after photodynamic therapy: Role of vascular endothelial growth factor

“…Cytological changes after PDT have been shown in a crayfish stretch receptor that consists of a single sensory neuron enwrapped by glial cells. These include swelling of some mitochondria, the Golgi apparatus, and endoplasmic reticulum cisterns [ 40 ]. The changes in the mitochondria and Golgi apparatus are the first to occur and persist the longest, and therefore these subcellular organelles are judged to have the greatest sensitivity to PDT [ 41 ].…”

Calcium in Neuronal and Glial Response to Axotomy

“…In some invertebrates, glia can enter the lumen of a transected axon up to its complete filling [43]. There exists a mechanism of vesicular transport of substances from glia to neuron [56][57][58][59][60][61], but it is still unknown whether the opposite process exists.…”

Dreams in Cybernetic Fugue

“…It was based on LEMM (54 researchers), but also absorbed a group devoted to the study of the effectiveness of capital investment from the Institute of Economics (11), the Department of Transportation Cybernetics from the Institute of Complex Transportation Problems (16), Nemchinov's former laboratory at the Council for the Study of the Productive Forces (SOPS), and the department of mathematical economics of Dorodnitsyn's Computer Center of the Academy of Sciences. 97 Most of these economists did not initially have a selfconscious identity as mathematical economists opposed to the ''political economy of socialism.'' They acquired one only through their traffic with cybernetics.…”