Measurements of dendritic conductance changes to GABA in granule cells of the rat dentate gyrus.
The magnitude of dendritic conductance changes occurring distantly from the somatic site of recording can be difficult to measure. We have used measurements of the neuronal time constant, tau 0, instead of the neuronal input resistance, RN, to estimate the resistance decrease that accompanies the depolarizing response of the dendrites of granule cells when GABA is applied. From the changes in tau 0, we estimated the reversal potential of the response and found that the conductance change accompanying a given GABA-mediated voltage response as measured at the cell body was the same regardless of where in the dendritic tree the drug was applied. On the other hand, RN changes underestimated the increase in conductance of the GABA responses in the distal dendrites and were not accurate for determining the reversal potential.
Blaxter
T J
TJ
Department of Physiology, University of Toronto, Ontario, Canada.
Carlen
P L
PL
D000465:Algorithms; D000818:Animals; D003712:Dendrites / Q000502:physiology*; D004553:Electric Conductivity; D006179:Gyrus Cinguli / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials; D051381:Rats; D011919:Rats, Inbred Strains; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D005680:gamma-Aminobutyric Acid