Dynamical and coherence resonance in a photoelectric neuron under autaptic regulation

Photoelectric neuron can perceive external illumination, and partial external energy is absorbed for generating output voltage and/or current. During the occurrence of photoelectric conversion, external illumination is filtered and transformed into equivalent electric stimulus, and then the external light signals are adjusted to control the neural activities by changing the excitability. Visual neuron has its intrinsic self-adaption, and appropriate firing patterns are induced under external illumination within specific frequency band. Therefore, the light-sensitive neuron developed from neural circuit driven by photocurrent can be used study the signal processing in visual neuron. Autapse is a special synaptic structure, which can create an auxiliary loop by inducing time-delayed feedback on membrane potential and the neural activities can be controlled. Autapse connection to a light-sensitive neuron and its modulation on neural activities is explored for knowing its self-adaption in neuron when phototube is connected as voltage/current source to the circuit. In addition, noise is applied on this biophysical neuron with autaptic driving and coherence resonance is induced. The mode selection is controlled by intrinsic parameters including gain and time delay in the autapse in presence of photocurrent even under noise. Furthermore, the intrinsic Hamilton energy for an isolated neuron under autaptic exciting is estimated, and the firing modes have important impact on the energy in the neuron. In presence of noise, the activation of autaptic driving is effective to control the firing patterns and induce possible coherence resonance.