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Annals of the New York Academy of... Dec 1975Both measurements and rough theoretical calculations suggest that both sites in the plasma membrane where the dark current enters and the mechanism that produces the... (Review)
Review
Both measurements and rough theoretical calculations suggest that both sites in the plasma membrane where the dark current enters and the mechanism that produces the intracellular excitatory transmitter of rod vision operate via ionophoric mechanisms with very low specific conductivities and high ionic specificities properties similar to those of carriers in artificial and natural membranes.
Topics: Animals; Biological Transport; Calcium; Cell Membrane; Ions; Membrane Potentials; Photoreceptor Cells; Structure-Activity Relationship
PubMed: 769641
DOI: 10.1111/j.1749-6632.1975.tb31492.x -
The Journal of Experimental Biology Aug 2019Among animals with visual processing mechanisms, the leech is a rare example in which all neurons can be identified. However, little is known about its visual system,...
Among animals with visual processing mechanisms, the leech is a rare example in which all neurons can be identified. However, little is known about its visual system, which is composed of several pigmented head eyes and photosensitive non-pigmented sensilla that are distributed across its entire body. Although several interneurons are known to respond to visual stimuli, their response properties are poorly understood. Among these, the S-cell system is especially intriguing: it is multimodal, spans the entire body of the leech and is thought to be involved in sensory integration. To improve our understanding of the role of this system, we tested its spectral sensitivity, spatial integration and adaptation properties. The response of the S-cell system to visual stimuli was found to be strongly dependent on the size of the area stimulated, and adaptation was local. Furthermore, an adaptation experiment demonstrated that at least two color channels contributed to the response, and that their contribution was dependent on the adaptation to the background. The existence of at least two color channels was further supported by transcriptomic evidence, which indicated the existence of at least two distinct groups of putative opsins for leeches. Taken together, our results show that the S-cell system has response properties that could be involved in the processing of spatial and color information of visual stimuli. We propose the leech as a novel system to understand visual processing mechanisms with many practical advantages.
Topics: Animals; Color Vision; Electrophysiological Phenomena; Interneurons; Leeches; Opsins; Photic Stimulation; Photoreceptor Cells; Transcriptome
PubMed: 31262786
DOI: 10.1242/jeb.201764 -
[Zhonghua Yan Ke Za Zhi] Chinese... Mar 2008To test the neuroprotective effect of lithium to the photoreceptor apoptosis in mouse model of retinal degeneration.
OBJECTIVE
To test the neuroprotective effect of lithium to the photoreceptor apoptosis in mouse model of retinal degeneration.
METHODS
It was a experimental study. FVB/NJ retinal degeneration mice were fed with lithium diet immediately after birth (P0). At day 7 (P7) and day 14 (P14), eye balls were removed and retinas were sectioned. Meanwhile blood was collected to measure the lithium concentration. H&E staining, TUNEL and immunofluorescence labeling were carried out to analysis the histology and photoreceptor cell apoptosis.
RESULTS
TUNEL-positive cells were found in the outer nuclear layer in the control group. The thickness and count of cell layer in P14 was much lower than that in P7 in the control group. In lithium-treat group, the ONL thickness and count of cell layer was much higher than that in the control group in P14, but has no significant difference with that in P7.
CONCLUSIONS
lithium can prevent photoreceptor cells from apoptosis in mouse model of retinal degeneration.
Topics: Animals; Apoptosis; Female; Lithium; Mice; Photoreceptor Cells; Retinal Degeneration
PubMed: 18785550
DOI: No ID Found -
Photophysiology 1970
Review
Topics: Animals; Color Perception; Electric Conductivity; Electroretinography; Fundus Oculi; Ganglia; Geniculate Bodies; Humans; Luminescent Measurements; Mathematics; Microchemistry; Models, Biological; Photochemistry; Photoreceptor Cells; Potentiometry; Primates; Retina; Retinal Pigments; Species Specificity; Spectrophotometry
PubMed: 4950131
DOI: No ID Found -
Nature Oct 1977
Topics: Action Potentials; Animals; Bufo marinus; Calcium; Electric Conductivity; In Vitro Techniques; Osmolar Concentration; Photic Stimulation; Photoreceptor Cells; Tetraethylammonium Compounds
PubMed: 413050
DOI: 10.1038/269707a0 -
The Journal of Cell Biology Jun 1976The ultrastructure of photoreceptor cells of the crayfish (P. clarkii) has been examined by means of thin sections and freeze-fracturing. The study reveals that in the...
The ultrastructure of photoreceptor cells of the crayfish (P. clarkii) has been examined by means of thin sections and freeze-fracturing. The study reveals that in the photoreceptor membranes there are particles associated primarily with the A faces of freeze-fracture preparations which have a mean diameter of 80-84 A and a density of 6,600 per per micrometer2. Treatment of the retina with digitonin (a substance capable of extracting visual photopigments) in Ringer's causes marked disruption of the hexagonal arrangement of the microvilli, breakdown of the microvilli into smaller segments, and gradual removal of the particles. The estimated photopigment concentration in the microvillus is 4,000 per micrometer. It is suggested that the observed particles represent the photopigment in situ.
Topics: Animals; Astacoidea; Cell Membrane; Digitonin; Photoreceptor Cells; Retinal Pigments
PubMed: 1270516
DOI: 10.1083/jcb.69.3.721 -
Neuroscience Mar 2007The purpose of this study was to investigate the presence of oxidative DNA damage in the photoreceptors of the rd1 mouse, an animal model for retinitis pigmentosa, and...
The purpose of this study was to investigate the presence of oxidative DNA damage in the photoreceptors of the rd1 mouse, an animal model for retinitis pigmentosa, and to determine if antioxidants could delay the progress of photoreceptor cell death. Retinas of rd1 mice and congenic wild type controls were examined for DNA oxidation and fragmentation. To study the rescue effect of antioxidants on retinal degeneration, rd1 retinas were studied in vitro and in vivo using lutein, zeaxanthin, alpha lipoic acid and reduced l-glutathione. For the in vitro studies, antioxidants were added to the culture medium. For the in vivo studies, postnatal day (PN3) pups of rd1 mice were fed antioxidants either individually or in combination and control rd1 animals received vehicle alone. Histological evaluation was performed using hematoxylin/eosin and avidin staining, as well as terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Many of the rd1 rod photoreceptors at PN11 displayed oxidative DNA damage and TUNEL positive reaction which co-localized in a subset of rod photoreceptors. Avidin-labeled rod photoreceptors were more abundant than the TUNEL positive photoreceptors of the rd1 mouse, indicating that oxidative DNA damage precedes fragmentation. The number of TUNEL positive and avidin positive cells was considerably decreased upon treatment with the combination of the antioxidants. Rescue of rd1 photoreceptors was significant at PN18 and PN17, respectively, in the in vitro and in vivo studies. In conclusion individual antioxidants had no significant rescue effect but the combination slowed down the rd1 rod photoreceptor degeneration, indicating an additive or synergistic effect.
Topics: Animals; Antioxidants; DNA Damage; Disease Models, Animal; Drug Therapy, Combination; Mice; Organ Culture Techniques; Photoreceptor Cells; Retina; Retinal Degeneration
PubMed: 17293057
DOI: 10.1016/j.neuroscience.2006.12.034 -
Vision Research 1977
Topics: Animals; Crustacea; Darkness; Ganglia; Insecta; Invertebrates; Mollusca; Photoreceptor Cells
PubMed: 878336
DOI: 10.1016/0042-6989(77)90039-6 -
Proceedings of the National Academy of... May 1996In the vertebrate retina, the light responses of post-receptor neurons depend on the ambient or background illumination. Using intracellular recording, we have found...
In the vertebrate retina, the light responses of post-receptor neurons depend on the ambient or background illumination. Using intracellular recording, we have found that a circadian clock regulates the light responses of dark-adapted fish cone horizontal cells. Goldfish were maintained on a 12-hr light/12-hr dark cycle. At different times of the day or night, retinas were superfused in darkness for 90 min ("prolonged darkness"), following which horizontal cells were impaled without the aid of any light flashes. In some of the experiments, fish were kept in constant darkness for 3-48 hr prior to surgery. After prolonged darkness during the night, but not during the day, the light responses of L-type cone horizontal cells resembled those of rod horizontal cells with respect to threshold, waveform, intensity-response functions, and spectral sensitivity. Following light sensitization during the night and day, the light responses of rod and cone horizontal cells were clearly different with respect to threshold, waveform, intensity-response functions, and spectral sensitivity. Under conditions of constant darkness for two full light/dark cycles, average responses of cone horizontal cells to a bright light stimulus during the subjective day were greater than during the subjective night. Prior reversal of the light/dark cycle reversed the 24-hr rhythm of cone horizontal cell responses to bright lights. In addition, following one full cycle of constant darkness, average cone horizontal cell spectral sensitivity during the subjective night closely matched that of rod horizontal cells, whereas average cone horizontal cell spectral sensitivity during the subjective day was similar to that of red (625 nm) cones. These results indicate that the effects of dark adaptation depend on the time of day and are regulated by a circadian clock so that cone input to cone horizontal cells predominates in the day and rod input predominates in the night.
Topics: Animals; Circadian Rhythm; Dark Adaptation; Electrophysiology; Goldfish; In Vitro Techniques; Light; Photoreceptor Cells; Retinal Cone Photoreceptor Cells
PubMed: 8643459
DOI: 10.1073/pnas.93.10.4655 -
Investigative Ophthalmology & Visual... Oct 1994The authors have established an organ culture method in which the the postnatal development and the structural integrity of the mouse retina can be maintained for at...
PURPOSE
The authors have established an organ culture method in which the the postnatal development and the structural integrity of the mouse retina can be maintained for at least 6 weeks. Additionally, they have examined the emergence and in vitro morphogenesis of the photoreceptors and the development of insoluble components of the interphotoreceptor matrix.
METHODS
Neural retinas and retinal pigment epithelia from 48-hour-old C3H ++/++ mice were cultured. At various ages, the tissues were fixed and cryosectioned or wholemounted. Photoreceptor development was studied by immunocytochemistry with visual pigment antibodies and by lectin cytochemistry. The ultrastructure of the photoreceptors was studied by electron microscopy.
RESULTS
Immunopositive rods and short-wave sensitive cones were detectable as early as 3 days after explantation. From this time on, matrix domains around cones were also identifiable and labelled with peanut agglutinin lectin. However, the antibody specific to the middle-wave sensitive cone pigment failed to recognize any cones throughout the 6-week culture period.
CONCLUSIONS
Both basic photoreceptor types appeared and developed in this organ culture system according to a timetable comparable to normal in vivo development. Surprisingly, under these circumstances, one of the two cone pigments was not expressed by any photoreceptors.
Topics: Animals; Animals, Newborn; Histocytochemistry; Mice; Mice, Inbred C3H; Morphogenesis; Organ Culture Techniques; Photoreceptor Cells; Pigment Epithelium of Eye; Retina; Retinal Cone Photoreceptor Cells; Retinal Pigments
PubMed: 7928189
DOI: No ID Found