PT  - JOURNAL ARTICLE
AU  - Greg Stuart
AU  - Nelson Spruston
TI  - Determinants of Voltage Attenuation in Neocortical Pyramidal Neuron Dendrites
AID  - 10.1523/JNEUROSCI.18-10-03501.1998
DP  - 1998 May 15
TA  - The Journal of Neuroscience
PG  - 3501--3510
VI  - 18
IP  - 10
4099  - http://www.jneurosci.org/content/18/10/3501.short
4100  - http://www.jneurosci.org/content/18/10/3501.full
SO  - J. Neurosci.1998 May 15; 18
AB  - How effectively synaptic and regenerative potentials propagate within neurons depends critically on the membrane properties and intracellular resistivity of the dendritic tree. These properties therefore are important determinants of neuronal function. Here we use simultaneous whole-cell patch-pipette recordings from the soma and apical dendrite of neocortical layer 5 pyramidal neurons to directly measure voltage attenuation in cortical neurons. When combined with morphologically realistic compartmental models of the same cells, the data suggest that the intracellular resistivity of neocortical pyramidal neurons is relatively low (∼70 to 100 Ωcm), but that voltage attenuation is substantial because of nonuniformly distributed resting conductances present at a higher density in the distal apical dendrites. These conductances, which were largely blocked by bath application of CsCl (5 mm), significantly increased steady-state voltage attenuation and decreased EPSP integral and peak in a manner that depended on the location of the synapse. Together these findings suggest that nonuniformly distributed Cs-sensitive and -insensitive resting conductances generate a “leaky” apical dendrite, which differentially influences the integration of spatially segregated synaptic inputs.