| Abstract |
Pyramidal cells are the most abundant type of neurons found in the cerebral cortex and their action has been associated with higher cognitive and emotional functions. These neurons have characteristic structure, consisting of a triangular shaped soma whereon descend two extended and complex dendritic trees, and a long bifurcated axon. All the morphological components of the pyramidal neurons exhibit significant variability across different brain areas and layers. Pyramidal neurons receive numerous synaptic inputs along their structure, whose integration in space and in time generates local dendritic spikes that shape their firing pattern. Two major electrophysiological categories of pyramidal cells have been established, based on the action potential frequency, generated from a fixed somatic stimulus: (1) cells that fire repetitive action potentials (Regular Spiking-RS) and (2) cells that fire clusters of 2-5 action potentials (Intrinsic Bursting-IB). In vitro and in silico scientific studies, correlate the firing patterns of the pyramidal neurons to their morphological features. This dissertation study provides a morphology analysis of the pyramidal cells, residing in the layer V of the rat prefrontal cortex and exams the influence of each part of the cell structure to their firing pattern. The role of the basal dendritic tree is pointed out, due to the so far focusing of the scientific approach on the apical tree. Moreover, the properties of the local generated NMDA dentritic spikes and their contribution to the somatic action potentials are investigated. The results suggest a correlation of the more complex apical and simpler basal trees to bursting firing patterns. Additionally, the more simple basal trees are correlated to greater number and lower latency of action potentials that are generated from the activation of the NMDA receptor. Consequently, it appears that the morphology of the pyramidal cells influences their firing patterns and, as a step further, the information coding that these neurons support.
Keywords: morphology, firing patterns, layer V pyramidal neurons, basal tree, NMDA spikes
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Επίδραση της μορφολογίας στα σχέδια εκφόρτισης των πυραμιδικών κυττάρων του προμετωπιαίου φλοιού αρουραίου
