The Effect of Astrocytes in Synaptic Transmission and Rhythmogenesis in Hippocampus

We study the role of astrocytes in the regulation of synaptic transmission and hippocampal rhythmogenesis. We examine the concept known as ‘tripartite synapse’ that refers to an existence of feedback loop between astrocytes and neurons. To study the peculiarities of astrocytic regulation of synaptic transmission, we built biological model (biological experiment) of neuron-astroglial network based on the hippocampal slices of laboratory mice. Light-sensitive receptors (channelrhodopsin 2) were pre-expressed in astrocytes, which were activated by light and transmit Ca ²⁺ ions. As a result, a cascade of biochemical reactions was activated in astrocytes, which leads to the gliotransmitters release and synaptic transmission modulation. Preliminary experimental resuts shown that the gliotransmitters released from optogenetically activated astrocytes have an impact on GABAergic currents on postsynaptic neuron in the tripartite synapse and regulate spontaneous sharp-wave-ripples (SWR). Obtained results of biological experiment were confirmed by mathematical modeling.