Phase-locking of hippocampal interneurons' membrane potential to neocortical up-down states.
During quiet wakefulness and sleep, and under anesthesia, the membrane potentials of neocortical pyramidal neurons show synchronous, slow oscillations, so-called up-down states (UDS), that can be detected in the local field potential (LFP). The influence of this synchronized, spontaneous neocortical activity on the hippocampus is largely unknown. We performed the first in vivo whole-cell recordings from hippocampal dorsal CA1 interneurons and found that their membrane potentials were phase-locked to neocortical up-down states with a small delay. These results provide strong evidence for cortico-hippocampal interaction and suggest that neocortical activity drives hippocampal interneurons during UDS.
Hahn
Thomas T G
TT
Department of Cell Physiology, Max Planck Institute for Medical Research, Heidelberg D-69120, Germany. thahn@mpimf-heidelberg.mpg.de
Sakmann
Bert
B
Mehta
Mayank R
MR
D000200:Action Potentials / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D007395:Interneurons / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology*; D019579:Neocortex / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology