Alteration of oscillatory potentials in diabetics induced by photocoagulation of the retina

1984 ◽  
Vol 221 (5) ◽  
pp. 230-233 ◽  
Author(s):  
R. Hennekes ◽  
R. Deschner
1991 ◽  
Vol 76 (4) ◽  
pp. 389-394 ◽  
Author(s):  
Xiao-Xin Li ◽  
Nin Yuan ◽  
Jie Hong ◽  
Pei Song

1991 ◽  
Vol 78 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Neal S Peachey ◽  
Kenneth R Alexander ◽  
Deborah J Derlacki ◽  
Phyllis Bobak ◽  
Gerald A Fishman

1993 ◽  
Vol 114 (2) ◽  
pp. 144-151 ◽  
Author(s):  
Nobuyoshi Nakatake ◽  
Aiko Hori ◽  
Akihiro Yasuhara ◽  
Hiroe Naito ◽  
Motohiro Yasuhara

2004 ◽  
Vol 91 (3) ◽  
pp. 1450-1454 ◽  
Author(s):  
P. Durante ◽  
C. G. Cardenas ◽  
J. A. Whittaker ◽  
S. T. Kitai ◽  
R. S. Scroggs

Ca2+ channel subtypes expressed by dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc) were studied using whole cell patch-clamp recordings and blockers selective for different channel types (L, N, and P/Q). Nimodipine (Nim, 2 μM), ω-conotoxin GVIA (Ctx, 1 μM), or ω-agatoxin IVA (Atx, 50 nM) blocked 27, 36, and 37% of peak whole cell Ca2+ channel current, respectively, indicating the presence of L-, N-, and P-type channels. Nim blocked approximately twice as much Ca2+ channel current near activation threshold compared with Ctx or Atx, suggesting that small depolarizations preferentially opened L-type versus N- or P-type Ca2+ channels. N- and L-channels in DA neurons opened over a significantly more negative voltage range than those in rat dorsal root ganglion cells, recorded from using identical conditions. These data provide an explanation as to why Ca2+-dependent spontaneous oscillatory potentials and rhythmic firing in DA neurons are blocked by L-channel but not N-channel antagonists and suggest that pharmacologically similar Ca2+ channels may exhibit different thresholds for activation in different types of neurons.


2019 ◽  
Vol 4 (4) ◽  
pp. 91-95
Author(s):  
Yu. N. Savina ◽  
S. I. Zhukova ◽  
A. V. Korolenko ◽  
D. A. Averyanov

Arterial hypertension is a problem not only for adults, but also for children, but there are very few data on changes in the organ of vision under the influence of an elevated level of blood pressure in children.The aim of the work is to identify disturbances of the choroidal blood flow in children and adolescents with essential arterial hypertension.Methods. Fifty patients with essential arterial hypertension were examined. The age of patients ranged from 10 to 17 years, the duration of the disease ranged from 2 months to 8 years. All patients underwent color Doppler mapping of the orbital vessels, registration of the oscillatory potentials of the ERG.Results. It was revealed that increased arterial pressure causes retinal and choroidal ischemia, which is accompanied primarily by impaired blood flow in the orbital vessels and is reflected in a decrease in the amplitude and deformation of the peaks of the ERG oscillatory potentials.Conclusion. Hypertension causes and supports retinal and choroidal ischemia, which is accompanied primarily by impaired blood flow in the orbital vessels, functional depression of photoreceptors, ganglion cells and neuroglia of the retina, aggravating the identified changes as the experience of essential hypertension increases. A marker of chorioretinal ischemia is amplitude depression, a change in the shape of the teeth of the oscillatory potentials of the ERG, which indicates a decrease in the functional activity of the retinal ganglion complex.That is, these changes can be considered as a predictor of hypertensive angioretinopathy in children and adolescents with essential arterial hypertension.


2018 ◽  
Vol 103 (3) ◽  
pp. 404-409 ◽  
Author(s):  
Kunihiko Akiyama ◽  
Kaoru Fujinami ◽  
Ken Watanabe ◽  
Toru Noda ◽  
Yozo Miyake ◽  
...  

AimsTo assess macular function in patients with macula-on rhegmatogenous retinal detachments (RRDs) using focal macular electroretinography (FMERG).MethodsThis is a prospective, observational case series of 27 patients diagnosed with a macula-on RRD. Foveal attachment was confirmed on spectral-domain optical coherence tomography. Eyes with any macular disorder, cataract, vitreous opacity or vitreous haemorrhage were excluded. FMERG was recorded in the affected and fellow eyes using a round stimulus 15° in diameter. The status of four retinal factors in the affected eyes was examined, that is, the number of involved quadrants, number of quadrants with retinal breaks, presence of an RRD invading the vascular arcade, and presence of a giant retinal tear. The implicit time and amplitude of the a-wave, b-wave and oscillatory potentials (OPs) were compared between the affected and fellow eyes using Wilcoxon signed-rank test. The influence of the four retinal factors on each FMERG component of the affected eyes was also evaluated using Mann-Whitney U test and Kruskal-Wallis test.ResultsSignificant reductions in the amplitudes of the a-waves (p=0.001), b-waves (p<0.001) and OPs (p=0.001) were observed in the affected eyes compared with the fellow eyes. There was no significant difference between the affected and fellow eyes in the implicit times of any components. None of the four retinal factors affected the parameters in the affected eyes.ConclusionAltered FMERG responses suggested the presence of macular dysfunction in eyes with macula-on RRDs.


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