Regensburg 2010 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 21: Neurobiophysics and Sensory Transduction
BP 21.6: Vortrag
Mittwoch, 24. März 2010, 15:45–16:00, H43
Effect of noisy adaptation on the interspike interval statistics of neurons — •Tilo Schwalger1, Karin Fisch2, Jan Benda2, and Benjamin Lindner1 — 1Max-Planck-Institut für Physik komplexer Systeme, Dresden — 2Biozentrum der LMU, Department Biologie II, Planegg-Martinsried
Adaptation and noise are key features of almost any neuron and have a profound impact on signal processing by neurons. This neural processing depends on the specific biophysical implementation of spike generation and spiking variability. In particular, different noise sources might result in markedly different statistics of neural spike trains. However, for many neurons, especially for sensory neurons, the major source of noise is hard to identify. Here, we study analytically a perfect integrate-and-fire neuron with adaptation and either white noise driving or noise resulting from fluctuations in the slow adaptation mechanism. The latter "adaptation noise" could, for instance, arise from channel noise associated to the slow adaption current. Surprisingly, we find a large difference in the statistics of interspike intervals (ISI): A stochastic adaptation current can be mapped to an effective colored noise driving giving rise to long-range positive ISI correlations and a pronounced peak of the ISI density. In contrast, when variability stems from white noise one observes anticorrelations and a less pronounced peak. These results suggest that insight into the major source of noise in certain neurons might be gained from the ISI statistics.