Doctoral dissertation studies mathematical models of nerve cells
Sander Paekivi, a doctoral student at Tallinn University鈥檚 School of Natural Sciences and Health, has defended his dissertation in which he studied models of nerve cells to find formulas describing the behavioural patterns of cells.
Mathematical models have been used in neuroscience for over a century. Paekivi explained that mathematical models can provide information about the functions of nerve cells, which can then be compared through experiments. 鈥淩educed systems are often more useful than the many detailed models that already exist, as they鈥檙e easier to solve and use in simulations,鈥 he said.
The model in question explores the nerve cell as a capacitor that stores within itself a charge up to a certain threshold value. After reaching this threshold, the neuron fires an electric signal known as a nerve impulse. This impulse is directed to further neurons, letting the electric signal spread throughout the brain. Paekivi says that mathematical models allow us to examine the static properties of this output impulse.
More specifically, in his dissertation he studied a certain type of memory effect (temporary addiction from past states) and how it affects nerve cell behaviour.
Experiments have shown that memory effects of the exponential law type should play a roll in nerve cell behaviour. Paekivi鈥檚 dissertation confirms the importance of exponential law memory effects in generating nerve impulses, bringing to light previously unknown behavioural patterns in similar models, such as bursts of high-frequency nerve impulses.
In addition, the work contains information about the location of such neurons in the brain 鈥 in areas where neurons receive signals from at least two different dendritic trees. 鈥淭hese sorts of mathematical expressions of neuron statistics along with biophysical clues are rare and represent an important outcome of the dissertation,鈥 Paekivi said.
The title of the dissertation is 鈥楾he influence of memory on the spike generation for diffusion models of neurons鈥. The dissertation was defended on Friday 28 August. The dissertation鈥檚 supervisors were Tallinn University鈥檚 Professor Emeritus Romi Mankin and Associate Professor Astrid Rekker. Its opponents were Tartu University鈥檚 Professor Emeritus and visiting professor Teet 脰rd and the University of Sofia鈥檚 Professor Michail D. Todorov.
The dissertation can be accessed in TLU鈥檚 Academic Library environment .
