Abstract: | The dominant paradigm in neuroscience assumes that nueron's excitability is characterised by repetitiveness: once the membrane voltage has crossed a threshold, changes occur in a stereotype pattern named action potential independent of the stimulation characteristics or history. Recent studies has demonstrated that this assumption doesn't hold, high frequency stimulation derive neuron excitability to a regime of complex dynamics and broadly distributed timescales. One interpretation suggests that these complex dynamics reflects residence of the system near a second order phase transition. The lecture will start with an explanation of this interpretation and proceed with presentation of an experiment that was carried out to establish it. In the experiment, neuron responsiveness was monitored under long lasting stimulation in different frequencies in order to identify increasing correlation time characterizes approaching a critic point. |