In vivo, low-resistance, whole-cell recordings from neurons in the anaesthetized and awake mammalian brain.
A blind patch-clamp technique for in vivo whole-cell recordings in the intact brain is described. Recordings were obtained from various neuronal cell types located 100-5,000 microm from the cortical surface. Access resistance of recordings was as low as 10 M Omega but increased with recording depth and animal age. Recordings were remarkably stable and it was therefore possible to obtain whole-cell recordings in awake, head-fixed animals. The whole-cell configuration permitted rapid dialysis of cells with a calcium buffer. In most neurons very little ongoing action potential (AP) activity was observed and the spontaneous firing rates were up to 50-fold less than what has been reported by extracellular unit recordings. AP firing in the brain might therefore be far sparser than previously thought.
Abteilung Zellphysiologie, Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, Heidelberg 69120, Germany. tmargrie@sun0.mpimf-heidelberg.mpg.de
Troy W
TW
Margrie
Michael
M
Brecht
Bert
B
Sakmann
D000200:Action Potentials / Q000502:physiology; D000758:Anesthesia; D000818:Animals; D001823:Body Composition; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D003243:Consciousness; D017097:Electric Impedance; D004594:Electrophysiology; D051379:Mice; D008839:Microelectrodes; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D014738:Vibrissae / Q000294:innervation