Melanopsin-derived visual responses under light adapted conditions in the mouse dLGN.
A direct projection from melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) reaches the primary visual thalamus (dorsal lateral geniculate nucleus; dLGN). The significance of this melanopsin input to the visual system is only recently being investigated. One unresolve...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2015-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC4379008?pdf=render |
| _version_ | 1818490858563960832 |
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| author | Katherine E Davis Cyril G Eleftheriou Annette E Allen Christopher A Procyk Robert J Lucas |
| author_facet | Katherine E Davis Cyril G Eleftheriou Annette E Allen Christopher A Procyk Robert J Lucas |
| author_sort | Katherine E Davis |
| collection | DOAJ |
| description | A direct projection from melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) reaches the primary visual thalamus (dorsal lateral geniculate nucleus; dLGN). The significance of this melanopsin input to the visual system is only recently being investigated. One unresolved question is the degree to which neurons in the dLGN could use melanopsin to track dynamic changes in light intensity under light adapted conditions. Here we set out to address this question. We were able to present full field steps visible only to melanopsin by switching between rod-isoluminant 'yellow' and 'blue' lights in a mouse lacking cone function (Cnga3-/-). In the retina these stimuli elicited melanopsin-like responses from a subset of ganglion cells. When presented to anaesthetised mice, we found that ~25-30% of visually responsive neurones in the contralateral dLGN responded to these melanopsin-isolating steps with small increases in firing rate. Such responses could be elicited even with fairly modest increases in effective irradiance (32% Michelson contrast for melanopsin). These melanopsin-driven responses were apparent at bright backgrounds (corresponding to twilight-daylight conditions), but their threshold irradiance was strongly dependent upon prior light exposure when stimuli were superimposed on a spectrally neutral ramping background light. While both onset and offset latencies were long for melanopsin-derived responses compared to those evoked by rods, there was great variability in these parameters with some cells responding to melanopsin steps in <1 s. These data indicate that a subset of dLGN units can employ melanopsin signals to detect modest changes in irradiance under photopic conditions. |
| first_indexed | 2024-12-10T17:23:01Z |
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| id | doaj.art-e39853dae3994fb291a39c26ff30932e |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-10T17:23:01Z |
| publishDate | 2015-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-e39853dae3994fb291a39c26ff30932e2022-12-22T01:39:56ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01103e012342410.1371/journal.pone.0123424Melanopsin-derived visual responses under light adapted conditions in the mouse dLGN.Katherine E DavisCyril G EleftheriouAnnette E AllenChristopher A ProcykRobert J LucasA direct projection from melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) reaches the primary visual thalamus (dorsal lateral geniculate nucleus; dLGN). The significance of this melanopsin input to the visual system is only recently being investigated. One unresolved question is the degree to which neurons in the dLGN could use melanopsin to track dynamic changes in light intensity under light adapted conditions. Here we set out to address this question. We were able to present full field steps visible only to melanopsin by switching between rod-isoluminant 'yellow' and 'blue' lights in a mouse lacking cone function (Cnga3-/-). In the retina these stimuli elicited melanopsin-like responses from a subset of ganglion cells. When presented to anaesthetised mice, we found that ~25-30% of visually responsive neurones in the contralateral dLGN responded to these melanopsin-isolating steps with small increases in firing rate. Such responses could be elicited even with fairly modest increases in effective irradiance (32% Michelson contrast for melanopsin). These melanopsin-driven responses were apparent at bright backgrounds (corresponding to twilight-daylight conditions), but their threshold irradiance was strongly dependent upon prior light exposure when stimuli were superimposed on a spectrally neutral ramping background light. While both onset and offset latencies were long for melanopsin-derived responses compared to those evoked by rods, there was great variability in these parameters with some cells responding to melanopsin steps in <1 s. These data indicate that a subset of dLGN units can employ melanopsin signals to detect modest changes in irradiance under photopic conditions.http://europepmc.org/articles/PMC4379008?pdf=render |
| spellingShingle | Katherine E Davis Cyril G Eleftheriou Annette E Allen Christopher A Procyk Robert J Lucas Melanopsin-derived visual responses under light adapted conditions in the mouse dLGN. PLoS ONE |
| title | Melanopsin-derived visual responses under light adapted conditions in the mouse dLGN. |
| title_full | Melanopsin-derived visual responses under light adapted conditions in the mouse dLGN. |
| title_fullStr | Melanopsin-derived visual responses under light adapted conditions in the mouse dLGN. |
| title_full_unstemmed | Melanopsin-derived visual responses under light adapted conditions in the mouse dLGN. |
| title_short | Melanopsin-derived visual responses under light adapted conditions in the mouse dLGN. |
| title_sort | melanopsin derived visual responses under light adapted conditions in the mouse dlgn |
| url | http://europepmc.org/articles/PMC4379008?pdf=render |
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