Dinâmica de circuitos neuronais

Abstract

Two identical autonomous dynamical systems, unidirectionally coupled in a sender receiver configuration, can exhibit a counter intuitive regime called anticipated synchronization (AS) if the receiver also receives a negative delayed self-feedback. This phenomenon was proposed in years 2000 and was verified inexperiments and computational simulations in electronic circuits and semi conductor lasers. Recently, it was shown that AS may occurin a circuit with three neurons with chemical synapses, where the self-feedback of the receiver neuron is provided by an inter neuron sending an inhibitory synapse. Furthermore, it was shown that a two-neuron model in the presence of an inhibitory autapse, which is a massive self-innervation present in cortical architecture, may also presents AS. Both the inhibitory autapse and the interneuron regulate the internal dynamics of the receiver neuron and acts as a negative delayed self-feedback required forth is circuits of few neurons to exhibit AS. In these biologically plausible scenarios, a smooth transition from the usual delayed synchronization (DS) to AS typically occurs when the inhibitory conductance is increased. The phenomenon was shown to be robust when model parameters were varied with in an acceptable physiological range. For extremely large values of the inhibition the systems can also present a phase-drift regime in which the receiver is faster than the sender. The inhibition also promotes an internal dynamic faster from the receiver when sender and receiver are uncoupled, which could be the mechanism underlying anticipated synchronization and the DS-AS transition via zero lag synchronization. Here, we reproduce these results and show that they are robust for different sets of parameters and neuron models.