Quantificação e agrupamento de neurônios in vitro usando mapas auto-organizáveis em matriz de microeletrodos
Resumen
Understanding how information is encoded in large neuronal networks
is one of the biggest challenges in neuroscience. A possible approach
to investigate the information processing capabilities of
neuronal nets is given by the use of dissociated neuronal cultures
attached to the Microelectrode Array. For instance, cortical neurons dissociated from rat embryos
cultivated in vitro in MEA show characteristic patterns of electrophysiological activities, ranging from isolated peaks in the early days
up to highly synchronized bursts after 3-4
weeks. In this context it is important to know
the spatial distribution function of neurons and, for that the
microscopic images are an alternative used to find out the positioning of the
neuron cells on the glass substrate of the MEA. However,
it is worth noting that microscopy is not always performed mainly
at short intervals during signal recording.
Of course there is a lack in the context of methods capable to
perform such functions without impairing the measurement of spontaneous signals
produced by the neuronal networks. To minimize this problem, it is proposed in this thesis
a framework for quantifying and classifying
neuron cells and thus estimate the topological arrangement of the culture,
by identifying spikes and bursts,
on the MEA electrodes. The framework developed for mapping
the topology of neurons, using Self-Organizing Map (SOM) neural network, is applied to the recording signals of the
experiment entitled Culture 371 of dissociated neuronal cells,
carried out at the Laboratory of Neuroengineering and
Bionanotechnology at the University of Genoa, Italy.
To validate the procedure, a topological map obtained as
result of this thesis is compared with a microscopic image obtained on day 38 of maturation
of Culture 371. Considering the majority number of MEA electrodes, the Chi-Square test resulted in confront of this validation. In addition, it is applied in the topological maps
the classification the neurons observed around the microelectrodes using
the analysis and separation of the registered spike waveforms.
Colecciones
El ítem tiene asociados los siguientes ficheros de licencia: