RT Journal Article
SR Electronic
T1 Selective Silencing of Individual Dendritic Branches by an mGlu2-Activated Potassium Conductance in Dentate Gyrus Granule Cells
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 7285
OP 7298
DO 10.1523/JNEUROSCI.4537-12.2013
VO 33
IS 17
A1 Brunner, János
A1 Ster, Jeanne
A1 Van-Weert, Susan
A1 Andrási, Tibor
A1 Neubrandt, Máté
A1 Corti, Corrado
A1 Corsi, Mauro
A1 Ferraguti, Francesco
A1 Gerber, Urs
A1 Szabadics, János
YR 2013
UL http://www.jneurosci.org/content/33/17/7285.abstract
AB Group II metabotropic glutamate receptors (mGlu-IIs) modulate hippocampal information processing through several presynaptic actions. We describe a novel postsynaptic inhibitory mechanism mediated by the mGlu2 subtype that activates an inwardly rectifying potassium conductance in the dendrites of DG granule cells of rats and mice. Data from glutamate-uncaging experiments and simulations indicate that mGlu2-activated potassium conductance uniformly reduces the peak amplitude of synaptic inputs arriving in the distal two-thirds of dendrites, with only minor effects on proximal inputs. This unique shunting profile is consistent with a peak expression of the mGlu2-activated conductance at the transition between the proximal and middle third of the dendrites. Further simulations under various physiologically relevant conditions showed that when a shunting conductance was activated in the proximal third of a single dendrite, it effectively modulated input to this specific branch while leaving inputs in neighboring dendrites relatively unaffected. Therefore, the restricted expression of the mGlu2-activated potassium conductance in the proximal third of DG granule cell dendrites represents an optimal localization for achieving the opposing biophysical requirements for uniform yet selective modulation of individual dendritic branches.