Abstract
The calculation and memory of position variables by temporal integration of velocity signals is essential for posture, the vestibulo-ocular reflex (VOR) and navigation. Integrator neurons exhibit persistent firing at multiple rates, which represent the values of memorized position variables. A widespread hypothesis is that temporal integration is the outcome of reverberating feedback loops within recurrent networks, but this hypothesis has not been proven experimentally. Here we present a single-cell model of a neural integrator. The nonlinear dynamics of calcium gives rise to propagating calcium wave-fronts along dendritic processes. The wave-front velocity is modulated by synaptic inputs such that the front location covaries with the temporal sum of its previous inputs. Calcium-dependent currents convert this information into concomitant persistent firing. Calcium dynamics in single neurons could thus be the physiological basis of the graded persistent activity and temporal integration observed in neurons during analog memory tasks.
| Original language | English |
|---|---|
| Pages (from-to) | 961-967 |
| Number of pages | 7 |
| Journal | Nature Neuroscience |
| Volume | 6 |
| Issue number | 9 |
| DOIs | |
| State | Published - 1 Sep 2003 |
Bibliographical note
Funding Information:We thank M. Goldman, D. Hansel, H.G. Rotstein, M. Spira and Y. Yarom for discussions. This work was supported in part by the Israeli Science Foundation (Center of Excellence 8006-00). Y.L. was supported by the Yeshaya Horowitz Association.