Original Research ARTICLE

Front. Syst. Neurosci., 10 April 2009 | doi: 10.3389/neuro.06.004.2009

Retinal oscillations carry visual information to cortex

1
Redwood Center for Theoretical Neuroscience, University of California Berkeley, CA, USA
2
Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
3
Center for Neuroscience, University of California, Davis, CA, USA
Thalamic relay cells fire action potentials that transmit information from retina to cortex. The amount of information that spike trains encode is usually estimated from the precision of spike timing with respect to the stimulus. Sensory input, however, is only one factor that influences neural activity. For example, intrinsic dynamics, such as oscillations of networks of neurons, also modulate firing pattern. Here, we asked if retinal oscillations might help to convey information to neurons downstream. Specifically, we made whole-cell recordings from relay cells to reveal retinal inputs (EPSPs) and thalamic outputs (spikes) and then analyzed these events with information theory. Our results show that thalamic spike trains operate as two multiplexed channels. One channel, which occupies a low frequency band (<30 Hz), is encoded by average firing rate with respect to the stimulus and carries information about local changes in the visual field over time. The other operates in the gamma frequency band (40–80 Hz) and is encoded by spike timing relative to retinal oscillations. At times, the second channel conveyed even more information than the first. Because retinal oscillations involve extensive networks of ganglion cells, it is likely that the second channel transmits information about global features of the visual scene.
Keywords:
LGN, retina, visual coding, natural stimuli, oscillations
Citation:
Koepsell K, Wang X, Vaingankar V, Wei Y, Wang Q, Rathbun DL, Usrey WM, Hirsch JA and Sommer FT (2009). Retinal oscillations carry visual information to cortex. Front. Syst. Neurosci. 3:4. doi: 10.3389/neuro.06.004.2009
Received:
5 December 2008;
 Paper pending published:
5 January 2009;
Accepted:
18 March 2009;
 Published online:
10 April 2009.

Edited by:

S. M. Sherman, University of Chicago, USA

Reviewed by:

Gregory C. DeAngelis, University of Rochester, USA
Michele Basso, University of Wisconsin, USA
Copyright:
© 2009 Koepsell, Wang, Vaingankar, Wei, Wang, Rathbun, Usrey, Hirsch and Sommer. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence:
Kilian Koepsell, Redwood Center for Theoretical Neuroscience, University of California Berkeley, 156 Stanley Hall, MC# 3220, Berkeley, CA 94720-3220, USA. e-mail: kilian@berkeley.edu; Friedrich T. Sommer, Redwood Center for Theoretical Neuroscience, University of California Berkeley, 156 Stanley Hall, MC# 3220, Berkeley, CA 94720-3220, USA. e-mail: fsommer@berkeley.edu
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