Optic nerve response and retinal structure in rainbow trout of different sizes

1993 ◽  
Vol 33 (13) ◽  
pp. 1739-1746 ◽  
Author(s):  
Luc Beaudet ◽  
Howard I. Browman ◽  
Craig W. Hawryshyn
1996 ◽  
Vol 36 (6) ◽  
pp. 797-816 ◽  
Author(s):  
Bernhard Jurklies ◽  
Alain Kaelin-Lang ◽  
Günter Niemeyer

2017 ◽  
Vol 284 (1862) ◽  
pp. 20170759 ◽  
Author(s):  
Iñigo Novales Flamarique

Besides colour and intensity, some invertebrates are able to independently detect the polarization of light. Among vertebrates, such separation of visual modalities has only been hypothesized for some species of anchovies whose cone photoreceptors have unusual ultrastructure that varies with retinal location. Here, I tested this hypothesis by performing physiological experiments of colour and polarization discrimination using the northern anchovy, Engraulis mordax . Optic nerve recordings showed that the ventro-temporal (VT), but not the ventro-nasal (VN), retina was polarization sensitive, and this coincided with the exclusive presence of polarization-sensitive photoreceptors in the VT retina. Spectral (colour) sensitivity recordings from the VN retina indicated the contribution of two spectral cone mechanisms to the optic nerve response, whereas only one contributed to the VT retina. This was supported by the presence of only one visual pigment in the VT retina and two in the VN retina, suggesting that only the VN retina was associated with colour sensitivity. Behavioural tests further demonstrated that anchovies could discriminate colour and the polarization of light using the ventral retina. Thus, in analogy with the visual system of some invertebrates, the northern anchovy has a retina with segregated retinal pathways for colour and polarization vision.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Riwanti Estiasari ◽  
Adisresti Diwyacitta ◽  
Muhammad Sidik ◽  
Ni Nengah Rida Ariarini ◽  
Freddy Sitorus ◽  
...  

Background. Multiple sclerosis (MS) is an autoimmune disease characterized by inflammation and demyelination of the central nervous system which often involves the optic nerve even though only 20% of the patients experience optic neuritis (ON). Objective. This study aims to compare the retinal structure and optic nerve function between patients with MS and healthy controls (HCs), evaluate optic nerve alterations in MS over 1-year follow-up, and analyze its correlations with disease duration, number of relapses, degree of disability, and different subtypes. Methods. This is a prospective cohort study involving 58 eyes of MS patients. Optic nerve function was evaluated with best-corrected visual acuity (BCVA), contrast sensitivity, and P100 latency, while the retinal structure was evaluated from the GCIPL and RNFL thickness measured with optical coherence tomography (OCT) and fundus photography. Results. The MS group had lower BCVA ( p = 0.001 ), contrast sensitivity ( p < 0.001 ), mean GCIPL thickness ( p < 0.001 ), and mean RNFL thickness ( p < 0.001 ) than HC. At 6 and 12 months of observations, GCIPL and RNFL (nasal quadrant) of MS patients decreased significantly ( p = 0.007 and p = 0.004 , respectively). Disease duration and the number of relapses correlated with delayed P100 latency (r = −0.61, p < 0.001 and r = −0.46, p = 0.02 ). GCIPL and RNFL in the SPMS subtype were thinner than in RRMS. Conclusions. The retinal structure and optic nerve function of MS patients are worse than those of normal individuals. GCIPL and RNFL thinning occurs at 6 and 12 months but do not correlate with disease duration, the number of relapses, and degree of disability.


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