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The effect of tetanic stimulation on functional connectivity

Witteveen, T. (2011) The effect of tetanic stimulation on functional connectivity.

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Abstract:It is generally believed that cognitive processes like learning and memory highly depend on synaptic connections between neurons. These synaptic connections are plastic, meaning that connections between neurons are continuously altered, new connections are formed and others disappear. The communication between neurons takes place at the synapse, at this synapse the membranes of neurons approach each other closely and are able to communicate with each other using either an electrical current or by the release of neurotransmitters. In Figure 1 a post-synaptic neuron, a pre- synaptic neuron and two synapses are shown. The pre- and postsynaptic neuron are connected through a synapse, this synapse affects the membrane potential of the postsynaptic cell. In this project however we are interested in global connectivity changes of a network of neurons caused by tetanic stimulation. A popular method to study cellular and network properties in-vitro is by using cultured neuronal networks. Electrical activity of these cultured neural networks can be measured using a multi electrode array (MEA). Studying these electrical signals provides us a way to study processes, similar to those occurring in our cortex. The MEA’s used in this project contained 60 electrodes (8 by 8 grid, without corner electrodes). These electrodes can both be used for measuring AP’s of nearby neurons and for stimulation of these neurons. Dimensions of these electrodes are small enough (10μm-30μm) for measuring single cell AP’s. Measurement of these AP’s can be used to determine relationships between electrode pairs, therefore providing a way to study connectivity of a network. This kind of network connectivity is called functional connectivity. Functional connectivity describes the behavioral relation between electrodes and neurons at these electrodes. Although functional relations between measured neurons are known, nothing can be said about the actual anatomical connection between those neurons. These may consist of multiple pathways between neurons, some examples are shown in Figure 4. These examples suggest a relation between synaptic connectivity and functional connectivity. Recent studies suggest that functional connectivity is directly related to synaptic connectivity. Thus changes in synaptic connections should lead to changes in functional relationships between the recorded neurons.
Item Type:Essay (Master)
Faculty:EEMCS: Electrical Engineering, Mathematics and Computer Science
Subject:44 medicine
Programme:Biomedical Engineering MSc (66226)
Link to this item:http://purl.utwente.nl/essays/69668
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