Inhibitory postsynaptic potentials carry synchronized frequency information in active cortical networks.
Temporal precision in spike timing is important in cortical function, interactions, and plasticity. We found that, during periods of recurrent network activity (UP states), cortical pyramidal cells in vivo and in vitro receive strong barrages of both excitatory and inhibitory postsynaptic potentials, with the inhibitory potentials showing much higher power at all frequencies above approximately 10 Hz and more synchrony between nearby neurons. Fast-spiking inhibitory interneurons discharged strongly in relation to higher-frequency oscillations in the field potential in vivo and possess membrane, synaptic, and action potential properties that are advantageous for transmission of higher-frequency activity. Intracellular injection of synaptic conductances having the characteristics of the recorded EPSPs and IPSPs reveal that IPSPs are important in controlling the timing and probability of action potential generation in pyramidal cells. Our results support the hypothesis that inhibitory networks are largely responsible for the dissemination of higher-frequency activity in cortex.
Hasenstaub
Andrea
A
Department of Neurobiology, Kavli Institute of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
Shu
Yousheng
Y
Haider
Bilal
B
Kraushaar
Udo
U
Duque
Alvaro
A
McCormick
David A
DA
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D003344:Cortical Synchronization; D019706:Excitatory Postsynaptic Potentials; D005289:Ferrets; D066298:In Vitro Techniques; D007395:Interneurons / Q000502:physiology; D008297:Male; D008564:Membrane Potentials; D009415:Nerve Net / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D009991:Oscillometry; D017966:Pyramidal Cells / Q000502:physiology; D011930:Reaction Time; D012032:Refractory Period, Electrophysiological; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission / Q000502:physiology*