A silicon implementation of the thalamic low threshold calcium current
A silicon model of the thalamic low threshold calcium current is presented. The channel current (IT) is the product of an activation and inactivation current, normalized by their sum. The individual currents are modeled by a simple current-mirror integrator circuit. A modified differential pair controls the threshold of activation while a leak transistor added to the inactivation mirror controls the rate of inactivation and deinactivation. The dynamics of IT are the result of the interaction between the fast activation and slow inactivation currents. By adjusting the base level of the activation current, we can realize a hyperpolarization activated cation current (Ih), responsible for rhythmic bursting in thalamic cells. By attaching the circuit to a constant leak integrate-and-fire neuron, we demonstrate in silicon both burst and tonic firing modes.
Date of presentation
Date Range for Data Collection (Start Date)
Date Range for Data Collection (End Date)
Digital Object Identifier
Series name and number
Copyright 2003 IEEE. Reprinted from Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society 2003, pages 2228-2231. Publisher URL: http://ieeexplore.ieee.org/xpl/tocresult.jsp?isNumber=28615&page=4 This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to firstname.lastname@example.org. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.