Abstract
PURPOSE. A retinal projection into the dorsal raphe nucleus (DRN), namely, the retinoraphe projection, exists in many species. The rat is one of several species in which a retino-raphe projection has been described; however, the retinal ganglion cell (RGC) types that contribute to this pathway are unknown. METHODS. Retrograde tracing via cholera toxin subunit B (CTB) was used to reveal DRN- projecting RGCs in rats, combined with intracellular injection in vitro, melanopsin immunostaining in whole-mounted retinas, and serotonin immunostaining to define the DRN. We modified methods of CTB injection into DRN used previously in order to avoid possible contamination with other retinorecipient regions, particularly the superior colliculus (SC). RESULTS. The majority of DRN-projecting RGCs showed alpha-like morphology, and some CTB- positive RGCs were colabeled with melanopsin. Approximately 80% of the total population of CTB-labeled DRN-projecting RGCs was alpha-like cells including ON alpha cells and OFF alpha cells; these alpha-like cells were melanopsin immunonegative. Approximately 10% of the remaining DRN-projecting RGCs were melanopsin immunopositive, in which the M1 subtype of intrinsically photosensitive retinal ganglion cell (ipRGC) provided the dominant projection of ipRGCs into DRN, with only few non-M1 ipRGCs involved. The DRN-projecting ipRGCs could be retrogradely labeled following tracer injection into all rostrocaudal aspects of the DRN. CONCLUSIONS. Both conventional RGCs with alpha-like morphology and melanopsin-expressing ipRGCs project into the rat DRN. Approximately 10% of DRN-projecting RGCs were colabeled with melanopsin, and the majority of these were the M1 subtype of ipRGCs. An ipRGC component of the retino-raphe projection may contribute to a sustained light-mediated modulation of DRN serotonin release.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 8373-8381 |
| Number of pages | 9 |
| Journal | Investigative Ophthalmology and Visual Science |
| Volume | 56 |
| Issue number | 13 |
| DOIs | |
| State | Published - Dec 1 2015 |
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Keywords
- Dorsal raphe nucleus
- IpRGCs
- Melanopsin
- Retinal ganglion cell
- Retinofugal projection
ASJC Scopus subject areas
- Ophthalmology
- Sensory Systems
- Cellular and Molecular Neuroscience
Cite this
The dorsal raphe nucleus receives afferents from alpha-like retinal ganglion cells and intrinsically photosensitive retinal ganglion cells in the rat. / Li, Xiaotao; Ren, Chaoran; Huang, Lu; Lin, Bin; Pu, Mingliang; Pickard, Gary E.; So, Kwok Fai.
In: Investigative Ophthalmology and Visual Science, Vol. 56, No. 13, 01.12.2015, p. 8373-8381.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The dorsal raphe nucleus receives afferents from alpha-like retinal ganglion cells and intrinsically photosensitive retinal ganglion cells in the rat
AU - Li, Xiaotao
AU - Ren, Chaoran
AU - Huang, Lu
AU - Lin, Bin
AU - Pu, Mingliang
AU - Pickard, Gary E.
AU - So, Kwok Fai
PY - 2015/12/1
Y1 - 2015/12/1
N2 - PURPOSE. A retinal projection into the dorsal raphe nucleus (DRN), namely, the retinoraphe projection, exists in many species. The rat is one of several species in which a retino-raphe projection has been described; however, the retinal ganglion cell (RGC) types that contribute to this pathway are unknown. METHODS. Retrograde tracing via cholera toxin subunit B (CTB) was used to reveal DRN- projecting RGCs in rats, combined with intracellular injection in vitro, melanopsin immunostaining in whole-mounted retinas, and serotonin immunostaining to define the DRN. We modified methods of CTB injection into DRN used previously in order to avoid possible contamination with other retinorecipient regions, particularly the superior colliculus (SC). RESULTS. The majority of DRN-projecting RGCs showed alpha-like morphology, and some CTB- positive RGCs were colabeled with melanopsin. Approximately 80% of the total population of CTB-labeled DRN-projecting RGCs was alpha-like cells including ON alpha cells and OFF alpha cells; these alpha-like cells were melanopsin immunonegative. Approximately 10% of the remaining DRN-projecting RGCs were melanopsin immunopositive, in which the M1 subtype of intrinsically photosensitive retinal ganglion cell (ipRGC) provided the dominant projection of ipRGCs into DRN, with only few non-M1 ipRGCs involved. The DRN-projecting ipRGCs could be retrogradely labeled following tracer injection into all rostrocaudal aspects of the DRN. CONCLUSIONS. Both conventional RGCs with alpha-like morphology and melanopsin-expressing ipRGCs project into the rat DRN. Approximately 10% of DRN-projecting RGCs were colabeled with melanopsin, and the majority of these were the M1 subtype of ipRGCs. An ipRGC component of the retino-raphe projection may contribute to a sustained light-mediated modulation of DRN serotonin release.
AB - PURPOSE. A retinal projection into the dorsal raphe nucleus (DRN), namely, the retinoraphe projection, exists in many species. The rat is one of several species in which a retino-raphe projection has been described; however, the retinal ganglion cell (RGC) types that contribute to this pathway are unknown. METHODS. Retrograde tracing via cholera toxin subunit B (CTB) was used to reveal DRN- projecting RGCs in rats, combined with intracellular injection in vitro, melanopsin immunostaining in whole-mounted retinas, and serotonin immunostaining to define the DRN. We modified methods of CTB injection into DRN used previously in order to avoid possible contamination with other retinorecipient regions, particularly the superior colliculus (SC). RESULTS. The majority of DRN-projecting RGCs showed alpha-like morphology, and some CTB- positive RGCs were colabeled with melanopsin. Approximately 80% of the total population of CTB-labeled DRN-projecting RGCs was alpha-like cells including ON alpha cells and OFF alpha cells; these alpha-like cells were melanopsin immunonegative. Approximately 10% of the remaining DRN-projecting RGCs were melanopsin immunopositive, in which the M1 subtype of intrinsically photosensitive retinal ganglion cell (ipRGC) provided the dominant projection of ipRGCs into DRN, with only few non-M1 ipRGCs involved. The DRN-projecting ipRGCs could be retrogradely labeled following tracer injection into all rostrocaudal aspects of the DRN. CONCLUSIONS. Both conventional RGCs with alpha-like morphology and melanopsin-expressing ipRGCs project into the rat DRN. Approximately 10% of DRN-projecting RGCs were colabeled with melanopsin, and the majority of these were the M1 subtype of ipRGCs. An ipRGC component of the retino-raphe projection may contribute to a sustained light-mediated modulation of DRN serotonin release.
KW - Dorsal raphe nucleus
KW - IpRGCs
KW - Melanopsin
KW - Retinal ganglion cell
KW - Retinofugal projection
UR - http://www.scopus.com/inward/record.url?scp=84952877800&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84952877800&partnerID=8YFLogxK
U2 - 10.1167/iovs.15-16614
DO - 10.1167/iovs.15-16614
M3 - Article
C2 - 26747768
AN - SCOPUS:84952877800
VL - 56
SP - 8373
EP - 8381
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 13
ER -