Electrotonically mediated oscillatory patterns in neuronal ensembles: an in vitro voltage-dependent dye-imaging study in the inferior olive.
Spatiotemporal profiles of ensemble subthreshold neuronal oscillation were studied in brainstem slices using high-speed voltage-sensitive dye imaging. After local electrical stimuli, the overall voltage profile demonstrated coherent oscillatory waves that spread over the inferior olive (IO). These oscillations were also observed in concurrently obtained intracellular recordings from IO neurons. Over the first few seconds after the stimuli, the optically recorded oscillations clustered into coherent groups comprising hundreds of neurons. Statistical analysis of the spatial profiles of these clusters revealed size fluctuation around stable core regions that were surrounded by a rim the diameter of which varied in time during the oscillation period. The neuronal ensemble oscillations were calcium derived and had an average frequency range of 1-7 Hz. This rhythmic response demonstrated a different spatiotemporal distribution in the presence of picrotoxin, which induced the merging of neuronal clusters into larger areas of coherent activity. The possibility that such clustering is a consequence of intrinsic oscillations in ensembles of coupled neurons was tested using mathematical modeling.
Leznik
Elena
E
Department of Physiology and Neuroscience, New York University School of Medicine, New York, New York 10016, USA.
Makarenko
Vladimir
V
Llinás
Rodolfo
R
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001683:Biological Clocks / Q000187:drug effects / Q000502:physiology*; D003198:Computer Simulation; D004558:Electric Stimulation; D005456:Fluorescent Dyes; D018756:GABA Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000502:physiology; D009415:Nerve Net / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D016571:Neural Networks, Computer; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009847:Olivary Nucleus / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D055095:Optics and Photonics; D010507:Periodicity; D010852:Picrotoxin / Q000494:pharmacology; D011726:Pyridinium Compounds; D051381:Rats; D017207:Rats, Sprague-Dawley; D012815:Signal Processing, Computer-Assisted
D005456:Fluorescent Dyes; D018756:GABA Antagonists; D010852:Picrotoxin; D011726:Pyridinium Compounds; C054158:RH 414