Investigation of synchronization in biological neural circuits

The nervous system is an organized structure in which vital functions are controlled in advanced organisms such as vertebrates or invertebrates. The vital functions of living organisms take place through electrical activities between neuronal communities connected by different topologies. Neuronal communication through these activities can also be monitored from local field potentials or EEG recordings, where brain rhythms at different frequencies exhibiting oscillatory behavior can be monitored. The synchronization of neuronal activity underlies the emergence of these rhythmic oscillations, which are of great importance in the nervous system. Nervous system, which has a complex system structure, consists of nerve cells and synapses in the form of transmission lines between each cell. In order to fully understand the system synchronization, starting from the smallest neural circuit, the complete analysis of neural networks over biophysically plausible parameters is essential and the main research topic. In this study, the synchronization conditions of the neuron pairs which consist of different types of synaptic connections of two nerve cells were investigated in terms of biologically reasonable changes in the intrinsic cell mechanisms and the communication between cells that make up the neuronal activity. In the simulations, deterministic and stochastic Hodgkin-Huxley (H-H) equations were used. The results showed that excitability states, levels of the synaptic and ionic conductivity are vital for the neurons to be synchronized. It has also shown that channel noise in neurons which have a stochastic nature is a realistic and auxiliary biological component to achieve synchronization.