Independent dendritic domains in the thalamic circuit

Compartment models of thalamocortical cells and thalamic interneurons of ra t lateral geniculate nucleus were used to match whole cell patch recordings showing input impedances of 118.7 +/- 22.5 and 606.5 +/- 220 Mohms, respec tively. As expected, simulation of continuous somatic current injection sho wed far less voltage drop-off to the distal dendrite as compared with previ ous studies based on sharp electrode recordings. However, simulation of mor e physiologically realistic high-frequency signals (action potentials and p ost synaptic potentials) showed substantial drop-off, suggesting the possib ility of independent processing by dendrodendritic domains and emphasizing the importance of synchrony of incoming signals. (C) 2000 Elsevier Science B.V. All rights reserved.