18,685 research outputs found
Impact of membrane bistability on dynamical response of neuronal populations
Neurons in many brain areas can develop pronounced depolarized state of
membrane potential (up state) in addition to the normal hyperpolarized down
state near the resting potential. The influence of the up state on signal
encoding, however, is not well investigated. Here we construct a
one-dimensional bistable neuron model and calculate the linear response to
noisy oscillatory inputs analytically. We find that with the appearance of an
up state, the transmission function is enhanced by the emergence of a local
maximum at some optimal frequency and the phase lag relative to the input
signal is reduced. We characterize the dependence of the enhancement of
frequency response on intrinsic dynamics and on the occupancy of the up state
Confinement induced by fermion damping in three-dimensional QED
The three-dimensional non-compact QED is known to exhibit weak confinement
when fermions acquire a finite mass via the mechanism of dynamical chiral
symmetry breaking. In this paper, we study the effect of fermion damping caused
by elastic scattering on the classical potential between fermions. By
calculating the vacuum polarization function that incorporates the fermion
damping effect, we show that fermion damping can induce a weak confinement even
when the fermions are massless and the chiral symmetry is not broken.Comment: 4 pages, no figur
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