| dc.description.abstract | Glial cells have been known as bystanders for many years. However, recent studies have revealed that besides neurons but also glial cells are essential for brain functions and neurological diseases. In fact, glia-neuron interaction plays a vital role in understanding the nervous system. Current research suggest possible involvement of glial cells during seizure generation. Although the characterization of glia-neuron communication could underlie future therapeutic applications for epilepsy, the mechanism behind neuroglia connectivity still remains as a mystery. Therefore, this thesis aimed to characterize neuron-glia communications in the zebrafish telencephalon through both electrophysiology, imaging and genetics tools.
To begin with, the morphology of zebrafish astrocytes were identified using confocal microscopy and compared with mammals. In addition, astrocytic network in zebrafish brain explants were investigated and spontaneous glial calcium bursts were displayed using epifluorescence calcium imaging. Moreover, neurons were stimulated indirectly by optogenetics activation of glia, besides K+ concentration had no impact on this communication expected. Next, to test the hypothesis regarding the generalized seizures are due to the extreme glutamate release from glia cells, the involvement of the EAAT2 transporter in seizure generation was investigated using perturbations and genetically modified animals. Lastly, the glia-neuron connectivity and glial calcium were examined after electrical stimulation of individual cells. As both glia and neuron are electrically active cells, in principle, electrical activation of both cells should lead alterations in glial calcium in nearby cells. To test this, current pulses were applied to single cells, either neuron or glia, however, no fluctuation was observed.
Taken together, this data provides more evidence for zebrafish neuroglia and its interactions. Nevertheless, further research needs to be performed to identify properties of glia-neuron interactions. | |