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High-Amplitude Positive Spikes Recorded Extracellularly in Cat Visual Cortex

Gold, Carl and Girardin, Cyrille C. and Martin, Kevan A. C. and Koch, Christof (2009) High-Amplitude Positive Spikes Recorded Extracellularly in Cat Visual Cortex. Journal of Neurophysiology, 102 (6). pp. 3340-3351. ISSN 0022-3077. PMCID PMC2804433. doi:10.1152/jn.91365.2008.

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We simulated the shape and amplitude of extracellular action potentials (APs or "spikes") using biophysical models based on detailed reconstructions of single neurons from the cat's visual cortex. We compared these predictions with spikes recorded from the cat's primary visual cortex under a standard protocol. The experimental data were derived from a large number of neurons throughout all layers. The majority of spikes were biphasic, with a dominant negative peak (mean amplitude, –0.11 mV), whereas a minority of APs had a dominant positive peak of +0.54-mV mean amplitude, with a maximum of +1.5 mV. The largest positive amplitude spikes were recorded in layer 5. The simulations demonstrated that a pyramidal neuron under known biophysical conditions may generate a negative peak with amplitude up to –1.5 mV, but that the amplitude of the positive peak may be at most 0.5 mV. We confirmed that spikes with large positive peaks were not produced by juxtacellular patch recordings. We conclude that there is a significant gap in our present understanding of either the spike-generation process in pyramidal neurons, the biophysics of extracellular recording, or both.

Item Type:Article
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URLURL TypeDescription DOIArticle CentralArticle
Koch, Christof0000-0001-6482-8067
Additional Information:© 2009 The American Physiological Society. Submitted 30 December 2008; accepted in final form 23 September 2009. We thank J. Anderson, T. Blanche, and R. Douglas for invaluable contributions to this study. This work was supported by National Institute of Mental Health (NIMH) Fellowship 1-F31-MH-070144-01A1 and Grant MH-12403, National Institute of Neurological Disorders and Stroke Grants NS-34994 and NS-43157, the NIMH-supported Conte Center for the Detection and Recognition of Objects, the National Science Foundation, the Swiss National Fund, and European Union Grant FP6-2005-015803.
Group:Koch Laboratory (KLAB)
Funding AgencyGrant Number
National Institute of Mental Health (NIMH)1-F31-MH-070144-01A1
National Institute of Neurological Disorders and Stroke (NINDS)NS-34994
National Institute of Neurological Disorders and Stroke (NINDS)NS-43157
Swiss National FundUNSPECIFIED
European UnionFP6-2005-015803
Issue or Number:6
PubMed Central ID:PMC2804433
Record Number:CaltechAUTHORS:20100105-092927703
Persistent URL:
Official Citation:Carl Gold, Cyrille C. Girardin, Kevan A. C. Martin, and Christof Koch High-Amplitude Positive Spikes Recorded Extracellularly in Cat Visual Cortex J Neurophysiol 102: 3340-3351, 2009. First published doi:10.1152/jn.91365.2008
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:17056
Deposited By: Tony Diaz
Deposited On:05 Jan 2010 19:50
Last Modified:08 Nov 2021 23:32

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