Visual Neuroscience最新文献

{"title":"Two mechanisms for direction selectivity in a model of the primate starburst amacrine cell.","authors":"Jiajia Wu, Yeon Jin Kim, Dennis M Dacey, John B Troy, Robert G Smith","doi":"10.1017/S0952523823000019","DOIUrl":"10.1017/S0952523823000019","url":null,"abstract":"<p><p>In a recent study, visual signals were recorded for the first time in starburst amacrine cells of the macaque retina, and, as for mouse and rabbit, a directional bias observed in calcium signals was recorded from near the dendritic tips. Stimulus motion from the soma toward the tip generated a larger calcium signal than motion from the tip toward the soma. Two mechanisms affecting the spatiotemporal summation of excitatory postsynaptic currents have been proposed to contribute to directional signaling at the dendritic tips of starbursts: (1) a \"morphological\" mechanism in which electrotonic propagation of excitatory synaptic currents along a dendrite sums bipolar cell inputs at the dendritic tip preferentially for stimulus motion in the centrifugal direction; (2) a \"space-time\" mechanism that relies on differences in the time-courses of proximal and distal bipolar cell inputs to favor centrifugal stimulus motion. To explore the contributions of these two mechanisms in the primate, we developed a realistic computational model based on connectomic reconstruction of a macaque starburst cell and the distribution of its synaptic inputs from sustained and transient bipolar cell types. Our model suggests that both mechanisms can initiate direction selectivity in starburst dendrites, but their contributions differ depending on the spatiotemporal properties of the stimulus. Specifically, the morphological mechanism dominates when small visual objects are moving at high velocities, and the space-time mechanism contributes most for large visual objects moving at low velocities.</p>","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":"40 ","pages":"E003"},"PeriodicalIF":1.1,"publicationDate":"2023-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10207453/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9685400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Colin Blakemore (1944–2022)","authors":"L. Spillmann","doi":"10.1017/S0952523822000074","DOIUrl":"https://doi.org/10.1017/S0952523822000074","url":null,"abstract":"Colin Blakemore, who died in Oxford on June 27 last year at the age of 78, was a world-renowned British neuroscientist and a highly influential andmuch-admiredmember of the vision community. As a medical student at Cambridge, Blakemore was influenced by Richard Gregory, and he subsequently maintained a keen interest in all aspects of visual science. He is best remembered for his studies on the development of the visual brain in kittens and the demonstration of neural plasticity. His findings were crucial for a better understanding of how brain cells organize themselves in response to the visual environment after birth. After graduating with a First at Cambridge, Blakemore went to the University of California at Berkeley in 1965 for his Ph.D. There he worked with Horace Barlow and Jack Pettigrew on binocular depth discrimination in the cat. He found that the response of binocular units in area V1 depended crucially on the alignment of the binocular stimulus in the two eyes. When the stimulus in one eye was off target, the response was vetoed. Blakemore returned to Cambridge in 1968 to take up a lectureship in physiology and, 3 years later, to become a Fellow at Downing College. It was during that time that he left the study of perception behind in favor of combining behavioral methods and neurophysiological techniques for the study of the visual system. In a ground-breaking experiment with Grahame Cooper, in 1970, he demonstrated that a kitten, which was reared in complete darkness since birth and then exposed to a vertically striped cylinder for 5 hours every day, was severely visually impaired when tested half a year later. In addition to showing no placement response and being seemingly oblivious toward an approaching object, the kitten behaved as if it was blind to a moving horizontal line. Conversely, a kitten that had been exposed to a horizontally striped cylinder, was blind to a moving vertical line. These results showed that the striate cortex could bemodified by selective experience early in life and that normal visual experience is crucial for normal maturation. When the authors recorded from cortical cells, the typical orientation tuning was gravely disturbed and only those cells tuned to near-vertical (or horizontal) responded, consistent with the behavioral deficit. This experiment triggered the great Nature–Nurture debate in the seventies and eighties. Numerous studies were performed in Cambridge and by other vision scientists, to further elucidate the early development of vision and visual perception. In the early 1970s, for example, Blakemore and Richard Van Sluyters embarked on a series of deprivation studies in kittens, in which they surgically closed the lids of one eye and showed that the normal binocular dominance of cortical cells shifted entirely to the other eye. Conversely, when the previously open eye was closed and the initially closed eye reopened, the ocular dominance was reversed, so that now every cell was dominated","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":"40 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44326981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of glaucoma on the spatial frequency processing of scenes in central vision.","authors":"Audrey Trouilloud,&nbsp;Elvia Ferry,&nbsp;Muriel Boucart,&nbsp;Louise Kauffmann,&nbsp;Aude Warniez,&nbsp;Jean-François Rouland,&nbsp;Carole Peyrin","doi":"10.1017/S0952523822000086","DOIUrl":"https://doi.org/10.1017/S0952523822000086","url":null,"abstract":"<p><p>Glaucoma is an eye disease characterized by a progressive vision loss usually starting in peripheral vision. However, a deficit for scene categorization is observed even in the preserved central vision of patients with glaucoma. We assessed the processing and integration of spatial frequencies in the central vision of patients with glaucoma during scene categorization, considering the severity of the disease, in comparison to age-matched controls. In the first session, participants had to categorize scenes filtered in low-spatial frequencies (LSFs) and high-spatial frequencies (HSFs) as a natural or an artificial scene. Results showed that the processing of spatial frequencies was impaired only for patients with severe glaucoma, in particular for HFS scenes. In the light of proactive models of visual perception, we investigated how LSF could guide the processing of HSF in a second session. We presented hybrid scenes (combining LSF and HSF from two scenes belonging to the same or different semantic category). Participants had to categorize the scene filtered in HSF while ignoring the scene filtered in LSF. Surprisingly, results showed that the semantic influence of LSF on HSF was greater for patients with early glaucoma than controls, and then disappeared for the severe cases. This study shows that a progressive destruction of retinal ganglion cells affects the spatial frequency processing in central vision. This deficit may, however, be compensated by increased reliance on predictive mechanisms at early stages of the disease which would however decline in more severe cases.</p>","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":"40 ","pages":"E001"},"PeriodicalIF":1.9,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9970733/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10796492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Overall patterns of eye-specific retino-geniculo-cortical projections to layers III, IV, and VI in primary visual cortex of the greater galago (<i>Otolemur crassicudatus</i>), and correlation with cytochrome oxidase blobs.","authors":"Jaime F Olavarria, Huixin Qi, Toru Takahata, Jon H Kaas","doi":"10.1017/S0952523822000062","DOIUrl":"10.1017/S0952523822000062","url":null,"abstract":"<p><p>Studies in the greater galago have not provided a comprehensive description of the organization of eye-specific retino-geniculate-cortical projections to the recipient layers in V1. Here we demonstrate the overall patterns of ocular dominance domains in layers III, IV, and VI revealed following a monocular injection of the transneuronal tracer wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP). We also correlate these patterns with the array of cytochrome oxidase (CO) blobs in tangential sections through the unfolded and flattened cortex. In layer IV, we observed for the first time that eye-specific domains form an interconnected pattern of bands 200-250 μm wide arranged such that they do not show orientation bias and do not meet the V1 border at right angles, as is the case in macaques. We also observed distinct WGA-HRP labeled patches in layers III and VI. The patches in layer III, likely corresponding to patches of K lateral geniculate nucleus (LGN) input, align with layer IV ocular dominance columns (ODCs) of the same eye dominance and overlap partially with virtually all CO blobs in both hemispheres, implying that CO blobs receive K LGN input from both eyes. We further found that CO blobs straddle the border between layer IV ODCs, such that the distribution of CO staining is approximately equal over ipsilateral and contralateral ODCs. These results, together with studies showing that a high percentage of cells in CO blobs are monocular, suggest that CO blobs consist of ipsilateral and contralateral subregions that are in register with underlying layer IV ODCs of the same eye dominance. In macaques and humans, CO blobs are centered on ODCs in layer IV. Our finding that CO blobs in galago straddle the border of neighboring layer IV ODCs suggests that this novel feature may represent an alternative way by which visual information is processed by eye-specific modular architecture in mammalian V1.</p>","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":"39 ","pages":"E007"},"PeriodicalIF":1.1,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9634673/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9242523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differences in chromatic noise suppression of luminance contrast discrimination in young and elderly people.","authors":"Rosa Maria Guimarães Brito,&nbsp;Bruna Rafaela Silva Sousa,&nbsp;Letícia Miquilini,&nbsp;Paulo Roney Kilpp Goulart,&nbsp;Marcelo Fernandes Costa,&nbsp;Dora Fix Ventura,&nbsp;Maria Izabel Tentes Cortes,&nbsp;Givago Silva Souza","doi":"10.1017/S0952523822000050","DOIUrl":"https://doi.org/10.1017/S0952523822000050","url":null,"abstract":"<p><p>Aging causes impairment of contrast sensitivity and chromatic discrimination, leading to changes in the perceptual interactions between color and luminance information. We aimed to investigate the influence of chromatic noise on luminance contrast thresholds in young and older adults. Forty participants were divided equally into Young (29.6 ± 6.3-year-old) and Elderly Groups (57.8 ± 6.6-year-old). They performed a luminance contrast discrimination task in the presence of chromatic noise maskers using a mosaic stimulus in a mosaic background. Four chromatic noise masking protocols were applied (protan, deutan, tritan, and no-noise protocols). We found that luminance contrast thresholds were significantly elevated by the addition of chromatic noise in both age groups (<i>P</i> < 0.05). In the Elderly group, but not the younger group, thresholds obtained in the tritan protocol were lower than those obtained from protan and deutan protocols (<i>P</i> < 0.05). For all protocols, the luminance contrast thresholds of elderly participants were higher than in young people (<i>P</i> < 0.01). Tritan chromatic noise was less effective in inhibiting luminance discrimination in elderly participants.</p>","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":" ","pages":"E006"},"PeriodicalIF":1.9,"publicationDate":"2022-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33502861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Glial cell response to constant low light exposure in rat retina.","authors":"Manuel G Bruera,&nbsp;María M Benedetto,&nbsp;Mario E Guido,&nbsp;Alicia L Degano,&nbsp;María A Contin","doi":"10.1017/S0952523822000049","DOIUrl":"https://doi.org/10.1017/S0952523822000049","url":null,"abstract":"<p><p>To study the macroglia and microglia and the immune role in long-time light exposure in rat eyes, we performed glial cell characterization along the time-course of retinal degeneration induced by chronic exposure to low-intensity light. Animals were exposed to light for periods of 2, 4, 6, or 8 days, and the retinal glial response was evaluated by immunohistochemistry, western blot and real-time reverse transcription polymerase chain reaction. Retinal cells presented an increased expression of the macroglia marker GFAP, as well as increased mRNA levels of microglia markers Iba1 and CD68 after 6 days. Also, at this time-point, we found a higher number of Iba1-positive cells in the outer nuclear layer area; moreover, these cells showed the characteristic activated-microglia morphology. The expression levels of immune mediators TNF, IL-6, and chemokines CX3CR1 and CCL2 were also significantly increased after 6 days. All the events of glial activation occurred after 5-6 days of constant light exposure, when the number of photoreceptor cells has already decreased significantly. Herein, we demonstrated that glial and immune activation are secondary to neurodegeneration; in this scenario, our results suggest that photoreceptor death is an early event that occurs independently of glial-derived immune responses.</p>","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":" ","pages":"E005"},"PeriodicalIF":1.9,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40377931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phosphorylation of cysteine string protein-α up-regulates the frequency of cholinergic waves via starburst amacrine cells","authors":"Ching-Feng Chen, R. R. Wo, Chien-Ting Huang, Tzu-Lin Cheng, Juu-Chin Lu, Chih-Tien Wang","doi":"10.1017/S0952523822000013","DOIUrl":"https://doi.org/10.1017/S0952523822000013","url":null,"abstract":"Abstract During the first postnatal week in rodents, cholinergic retinal waves initiate in starburst amacrine cells (SACs), propagating to retinal ganglion cells (RGCs) and visual centers, essential for visual circuit refinement. By modulating exocytosis in SACs, dynamic changes in the protein kinase A (PKA) activity can regulate the spatiotemporal patterns of cholinergic waves. Previously, cysteine string protein-α (CSPα) is found to interact with the core exocytotic machinery by PKA-mediated phosphorylation at serine 10 (S10). However, whether PKA-mediated CSPα phosphorylation may regulate cholinergic waves via SACs remains unknown. Here, we examined how CSPα phosphorylation in SACs regulates cholinergic waves. First, we identified that CSPα1 is the major isoform in developing rat SACs and the inner plexiform layer during the first postnatal week. Using SAC-specific expression, we found that the CSPα1-PKA-phosphodeficient mutant (CSP-S10A) decreased wave frequency, but did not alter the wave spatial correlation compared to control, wild-type CSPα1 (CSP-WT), or two PKA-phosphomimetic mutants (CSP-S10D and CSP-S10E). These suggest that CSPα-S10 phosphodeficiency in SACs dampens the frequency of cholinergic waves. Moreover, the level of phospho-PKA substrates was significantly reduced in SACs overexpressing CSP-S10A compared to control or CSP-WT, suggesting that the dampened wave frequency is correlated with the decreased PKA activity. Further, compared to control or CSP-WT, CSP-S10A in SACs reduced the periodicity of wave-associated postsynaptic currents (PSCs) in neighboring RGCs, suggesting that these RGCs received the weakened synaptic inputs from SACs overexpressing CSP-S10A. Finally, CSP-S10A in SACs decreased the PSC amplitude and the slope to peak PSC compared to control or CSP-WT, suggesting that CSPα-S10 phosphodeficiency may dampen the speed of the SAC-RGC transmission. Thus, via PKA-mediated phosphorylation, CSPα in SACs may facilitate the SAC-RGC transmission, contributing to the robust frequency of cholinergic waves.","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":"39 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44241022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The mosaic of AII amacrine cell bodies in rat retina is indistinguishable from a random distribution.","authors":"Jian Hao Liu,&nbsp;David Olukoya Peter,&nbsp;Maren Sofie Faldalen Guttormsen,&nbsp;Md Kaykobad Hossain,&nbsp;Yola Gerking,&nbsp;Margaret Lin Veruki,&nbsp;Espen Hartveit","doi":"10.1017/S0952523822000025","DOIUrl":"https://doi.org/10.1017/S0952523822000025","url":null,"abstract":"<p><p>The vertebrate retina contains a large number of different types of neurons that can be distinguished by their morphological properties. Assuming that no location should be without a contribution from the circuitry and function linked to a specific type of neuron, it is expected that the dendritic trees of neurons belonging to a type will cover the retina in a regular manner. Thus, for most types of neurons, the contribution to visual processing is thought to be independent of the exact location of individual neurons across the retina. Here, we have investigated the distribution of AII amacrine cells in rat retina. The AII is a multifunctional amacrine cell found in mammals and involved in synaptic microcircuits that contribute to visual processing under both scotopic and photopic conditions. Previous investigations have suggested that AIIs are regularly distributed, with a nearest-neighbor distance regularity index of ~4. It has been argued, however, that this presumed regularity results from treating somas as points, without taking into account their actual spatial extent which constrains the location of other cells of the same type. When we simulated random distributions of cell bodies with size and density similar to real AIIs, we confirmed that the simulated distributions could not be distinguished from the distributions observed experimentally for AIIs in different regions and eccentricities of the retina. The developmental mechanisms that generate the observed distributions of AIIs remain to be investigated.</p>","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":"39 ","pages":"E004"},"PeriodicalIF":1.9,"publicationDate":"2022-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9107964/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10597698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological and electrophysiological specializations of photoreceptors in the love spot of hover fly Volucella pellucens.","authors":"Irina I Ignatova,&nbsp;Ilkka Miinalainen,&nbsp;Roman V Frolov","doi":"10.1017/S0952523821000146","DOIUrl":"https://doi.org/10.1017/S0952523821000146","url":null,"abstract":"<p><p>Studies of functional variability in the compound eyes of flies reveal superior temporal resolution of photoreceptors from the frontal areas that mediate binocular vision, and in males mate recognition and pursuit. However, the mechanisms underlying differences in performance are not known. Here, we investigated properties of hover fly Volucella pellucens photoreceptors from two regions of the retina, the frontal-dorsal \"love spot\" and the lateral one. Morphologically, the microvilli of the frontal-dorsal photoreceptors were relatively few in number per rhabdomere cross-section, short and narrow. In electrophysiological experiments involving stimulation with prolonged white-noise and natural time intensity series, frontal-dorsal photoreceptors demonstrated comparatively high corner frequencies and information rates. Investigation of possible mechanisms responsible for their superior performance revealed significant differences in the properties of quantum bumps, and, unexpectedly, relatively high absolute sensitivity of the frontal-dorsal photoreceptors. Analysis of light adaptation indicated that photoreceptors from two regions adapt similarly but because frontal-dorsal photoreceptors were depolarized much stronger by the same stimuli than the lateral photoreceptors, they reached a deeper state of adaptation associated with higher corner frequencies of light response. Recordings from the photoreceptor axons were characterized by spike-like events that can significantly expand the frequency response range. Seamless integration of spikes into the graded voltage responses was enabled by light adaptation mechanisms that accelerate kinetics and decrease duration of depolarizing light response transients.</p>","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":" ","pages":"E015"},"PeriodicalIF":1.9,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39506704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and function of the gap junctional network of photoreceptive ganglion cells.","authors":"Xiwu Zhao,&nbsp;Kwoon Y Wong","doi":"10.1017/S0952523821000134","DOIUrl":"https://doi.org/10.1017/S0952523821000134","url":null,"abstract":"<p><p>Intrinsically photosensitive retinal ganglion cells (ipRGCs) signal not only anterogradely to drive behavioral responses, but also retrogradely to some amacrine interneurons to modulate retinal physiology. We previously found that all displaced amacrine cells with spiking, tonic excitatory photoresponses receive gap-junction input from ipRGCs, but the connectivity patterns and functional roles of ipRGC-amacrine coupling remained largely unknown. Here, we injected PoPro1 fluorescent tracer into all six types of mouse ipRGCs to identify coupled amacrine cells, and analyzed the latter's morphological and electrophysiological properties. We also examined how genetically disrupting ipRGC-amacrine coupling affected ipRGC photoresponses. Results showed that ipRGCs couple with not just ON- and ON/OFF-stratified amacrine cells in the ganglion-cell layer as previously reported, but also OFF-stratified amacrine cells in both ganglion-cell and inner nuclear layers. M1- and M3-type ipRGCs couple mainly with ON/OFF-stratified amacrine cells, whereas the other ipRGC types couple almost exclusively with ON-stratified ones. ipRGCs transmit melanopsin-based light responses to at least 93% of the coupled amacrine cells. Some of the ON-stratifying ipRGC-coupled amacrine cells exhibit transient hyperpolarizing light responses. We detected bidirectional electrical transmission between an ipRGC and a coupled amacrine cell, although transmission was asymmetric for this particular cell pair, favoring the ipRGC-to-amacrine direction. We also observed electrical transmission between two amacrine cells coupled to the same ipRGC. In both scenarios of coupling, the coupled cells often spiked synchronously. While ipRGC-amacrine coupling somewhat reduces the peak firing rates of ipRGCs' intrinsic melanopsin-based photoresponses, it renders these responses more sustained and longer-lasting. In summary, ipRGCs' gap junctional network involves more amacrine cell types and plays more roles than previously appreciated.</p>","PeriodicalId":23556,"journal":{"name":"Visual Neuroscience","volume":"38 ","pages":"E014"},"PeriodicalIF":1.9,"publicationDate":"2021-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9753619/pdf/nihms-1855317.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10696150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}