Activation of kinetically distinct synaptic conductances on inhibitory interneurons by electrotonically overlapping afferents.
Mossy fiber (MF) and CA3 collateral (CL) axons activate common interneurons via synapses comprised of different AMPA receptors to provide feedforward and feedback inhibitory control of the CA3 hippocampal network. Because synapses potentially occur over variable electrotonic distances that distort somatically recorded synaptic currents, it is not known whether the underlying afferent-specific synaptic conductances are associated with different time courses. Using a somatic voltage jump technique to alter the driving force at the site of the synapse, we demonstrate that MF and CL synapses overlap in electrotonic location yet differ in conductance time course. Thus, afferent-specific conductance time courses allow single interneurons to differentially integrate feedforward and feedback information without the need to segregate distinct AMPA receptor subunits to different electrotonic domains.
Laboratory of Cellular and Synaptic Neurophysiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Harrison C
HC
Walker
J Josh
JJ
Lawrence
Chris J
CJ
McBain
D000344:Afferent Pathways / Q000166:cytology / Q000378:metabolism; D000818:Animals; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D004558:Electric Stimulation; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D005246:Feedback / Q000502:physiology; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D007700:Kinetics; D019599:Mossy Fibers, Hippocampal / Q000378:metabolism* / Q000648:ultrastructure; D009415:Nerve Net / Q000378:metabolism / Q000648:ultrastructure; D009431:Neural Conduction / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D009924:Organ Culture Techniques; D051381:Rats; D011930:Reaction Time / Q000502:physiology; D018091:Receptors, AMPA / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology*; D013997:Time Factors
D018091:Receptors, AMPA