Lesica, NA;
Weng, C;
Jin, JZ;
Yeh, CI;
Alonso, JM;
Stanley, GB;
(2006)
Dynamic encoding of natural luminance sequences by LGN bursts.
PLOS BIOL
, 4
(7)
, Article e209. 10.1371/journal.pbio.0040209.
![[thumbnail of 88326.pdf]](https://discovery.ucl.ac.uk/style/images/fileicons/application_pdf.png) Preview |
PDF
88326.pdf Download (427kB) |
Abstract
In the lateral geniculate nucleus (LGN) of the thalamus, visual stimulation produces two distinct types of responses known as tonic and burst. Due to the dynamics of the T-type Ca2+ channels involved in burst generation, the type of response evoked by a particular stimulus depends on the resting membrane potential, which is controlled by a network of modulatory connections from other brain areas. In this study, we use simulated responses to natural scene movies to describe how modulatory and stimulus-driven changes in LGN membrane potential interact to determine the luminance sequences that trigger burst responses. We find that at low resting potentials, when the T channels are deinactivated and bursts are relatively frequent, an excitatory stimulus transient alone is sufficient to evoke a burst. However, to evoke a burst at high resting potentials, when the T channels are inactivated and bursts are relatively rare, prolonged inhibitory stimulation followed by an excitatory transient is required. We also observe evidence of these effects in vivo, where analysis of experimental recordings demonstrates that the luminance sequences that trigger bursts can vary dramatically with the overall burst percentage of the response. To characterize the functional consequences of the effects of resting potential on burst generation, we simulate LGN responses to different luminance sequences at a range of resting potentials with and without a mechanism for generating bursts. Using analysis based on signal detection theory, we show that bursts enhance detection of specific luminance sequences, ranging from the onset of excitatory sequences at low resting potentials to the offset of inhibitory sequences at high resting potentials. These results suggest a dynamic role for burst responses during visual processing that may change according to behavioral state.
| Type: | Article |
|---|---|
| Title: | Dynamic encoding of natural luminance sequences by LGN bursts |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1371/journal.pbio.0040209 |
| Publisher version: | http://dx.doi.org/10.1371/journal.pbio.0040209 |
| Language: | English |
| Additional information: | © 2006 Lesica et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: NAL and GBS were supported by National Geospatial-Intelligence Agency Grant HM1582-05-C-0009. CW, JJ, CIY, and JMA were supported by National Eye Institute Grant EY-05253 and by the Research Foundation of The State University of New York. |
| Keywords: | LATERAL GENICULATE-NUCLEUS, VISUAL INFORMATION, THALAMOCORTICAL RELAY, RECEPTIVE-FIELDS, THALAMIC NEURONS, CAT, SLEEP, MODE, RESPONSES, SPIKES |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Brain Sciences > The Ear Institute |
| URI: | https://discovery.ucl.ac.uk/id/eprint/88326 |
Archive Staff Only
 |
View Item |
