RESUMO

We study the transient regime of type-II biophysical neuron models and determine the scaling behavior of relaxation times tau near but below the repetitive firing critical current, tau approximately or equal to C(I(c)-I)(-Delta). For both the Hodgkin-Huxley and Morris-Lecar models we find that the critical exponent is independent of the numerical integration time step and that both systems belong to the same universality class, with Delta=1/2. For appropriately chosen parameters, the FitzHugh-Nagumo model presents the same generic transient behavior, but the critical region is significantly smaller. We propose an experiment that may reveal nontrivial critical exponents in the squid axon.

Assuntos

Potenciais de Ação/fisiologia , Relógios Biológicos/fisiologia , Limiar Diferencial/fisiologia , Modelos Neurológicos , Plasticidade Neuronal/fisiologia , Neurônios/fisiologia , Adaptação Fisiológica/fisiologia , Animais , Axônios/fisiologia , Simulação por Computador , Decapodiformes , Fatores de Tempo