Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character最新文献_第2页

Implementation of the template model of vision. 实现模板模型的视觉化。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-06-22 DOI: 10.1098/rspb.1990.0035

P J Sobey, G A Horridge

{"title":"Implementation of the template model of vision.","authors":"P J Sobey, G A Horridge","doi":"10.1098/rspb.1990.0035","DOIUrl":"https://doi.org/10.1098/rspb.1990.0035","url":null,"abstract":"Adopting principles learnt from insect vision we have constructed model of a general-purpose front-end visual system for motion detection that is designed to operate in parallel along each photoreceptor axis with only local connections. The model is also designed to assist electrophysiological analysis of visual processing because it puts the response to a moving scene into sets of template responses similar to the distribution of activity among different neurons. An earlier template model divided the visual image into the fields of adjacent receptors, measured as intensity or receptor modulation at small increments of time. As soon as we used this model with natural scenes, however, we found that we had to look at changes in intensity, not intensity itself. Running the new model also generated new insights into the effects of very fast motion, of blurring the image, and the value of lateral inhibition. We also experimented with ways of measuring the angular velocity of the image moving across the eye. The camera eye is moved at a known speed and the range to objects is calculated from the angular velocity of contrasts moving across the receptor array. The original template model is modified so that contrast is saturated in a new representation of the original image data. This reduces the 8-bit grey-scale image to a log, 3 = 1.6-bit image, which becomes the input to a look-up table of templates. The output consists of groups of responding templates in specific ratios that define the input features, and these ratios lead into types of invariance at a higher level of further logic. At any stage, there can be persistent parallel inputs from all earlier stages. This design would enable groups of templates to be tuned to different expected situations, such as different velocities, different directions and different types of edges.","PeriodicalId":54561,"journal":{"name":"Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character","volume":"240 1298","pages":"211-29"},"PeriodicalIF":0.0,"publicationDate":"1990-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1098/rspb.1990.0035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13131696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

Interpretation of agonist affinity estimations: the question of distributed receptor states. 激动剂亲和估计的解释:分布受体状态的问题。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-06-22 DOI: 10.1098/rspb.1990.0051

J W Black, N P Shankley

引用次数: 26

Energy absorption from ocean waves: a free ride for cetaceans. 从海浪中吸收能量:鲸目动物的免费乘车。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-06-22 DOI: 10.1098/rspb.1990.0054

N Bose, J Lien

引用次数: 46

Mutational order: a major stochastic process in evolution. 突变顺序:进化中一个主要的随机过程。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-05-22 DOI: 10.1098/rspb.1990.0025

G S Mani, B C Clarke

引用次数: 164

Blocking actions of heptachlor at an insect central nervous system GABA receptor. 七氯胺对昆虫中枢神经系统GABA受体的阻断作用。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-05-22 DOI: 10.1098/rspb.1990.0029

S C Lummis, S D Buckingham, J J Rauh, D B Sattelle

{"title":"Blocking actions of heptachlor at an insect central nervous system GABA receptor.","authors":"S C Lummis, S D Buckingham, J J Rauh, D B Sattelle","doi":"10.1098/rspb.1990.0029","DOIUrl":"https://doi.org/10.1098/rspb.1990.0029","url":null,"abstract":"The actions of the polychlorocycloalkane insecticide heptachlor, and its epoxide metabolite, were examined on GABA receptors in insects and vertebrates. Electrophysiological experiments on the cell body of the cockroach (Periplaneta americana) fast coxal depressor motor neuron (Df), and GABA-activated 36Cl- uptake experiments on microsacs prepared from cockroach ventral nerve cords showed that both heptachlor and heptachlor epoxide blocked functional GABA receptors. The block appeared to be non-competitive and was voltage-independent over the membrane potential range -75 mV to -110 mV. There was no significant difference between the potencies of heptachlor and heptachlor epoxide in the functional assays for insect GABA receptors. Both compounds inhibited [35S]-t-butylbicyclophosphorothionate [( 35S]TBPS) binding in insects and vertebrates. The findings provide further evidence for block of an insect GABA receptor/Cl- channel by the cyclodiene class of polychlorocycloalkanes, and reveal differences in the insecticide-[35S]TBPS binding site interactions of insects and vertebrates.","PeriodicalId":54561,"journal":{"name":"Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character","volume":"240 1297","pages":"97-106"},"PeriodicalIF":0.0,"publicationDate":"1990-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1098/rspb.1990.0029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12858850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

A model of the single atrial cell: relation between calcium current and calcium release. 单心房细胞模型:钙电流与钙释放的关系。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-05-22 DOI: 10.1098/rspb.1990.0028

Y E Earm, D Noble

{"title":"A model of the single atrial cell: relation between calcium current and calcium release.","authors":"Y E Earm, D Noble","doi":"10.1098/rspb.1990.0028","DOIUrl":"https://doi.org/10.1098/rspb.1990.0028","url":null,"abstract":"The hypothesis that calcium release from the sarcoplasmic reticulum in cardiac muscle is induced by rises in free cytosolic calcium (Fabiato 1983, Am. J. Physiol 245) allows the possibility that the release could be at least partly regenerative. There would then be a non-linear relation between calcium current and calcium release. We have investigated this possibility in a single-cell version of the rabbit-atrial model developed by Hilgemann & Noble (1987, Proc. R. Soc. Lond. B 230). The model predicts different voltage ranges of activation for calcium-dependent processes (like the sodium-calcium exchange current, contraction or Fura-2 signals) and the calcium current, in agreement with the experimental results obtained by Earm et al. (1990, Proc. R. Soc. Lond. B 240) on exchange current tails, Cannell et al. (1987, Science, Wash. 238) by using Fura-2 signals, and Fedida et al. (1987, J. Physiol., Lond. 385) and Talo et al. (1988, Biology of isolated adult cardiac myocytes) by using contraction. However, when the Fura-2 concentration is sufficiently high (greater than 200 microM) the activation ranges become very similar as the buffering properties of Fura-2 are sufficient to remove the regenerative effect. It is therefore important to allow for the buffering properties of calcium indicators when investigating the correlation between calcium current and calcium release.","PeriodicalId":54561,"journal":{"name":"Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character","volume":"240 1297","pages":"83-96"},"PeriodicalIF":0.0,"publicationDate":"1990-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1098/rspb.1990.0028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13131270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 111

Inward current generated by Na-Ca exchange during the action potential in single atrial cells of the rabbit. 家兔单心房细胞动作电位时钠钙交换产生的内向电流。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-05-22 DOI: 10.1098/rspb.1990.0027

Y E Earm, W K Ho, I S So

{"title":"Inward current generated by Na-Ca exchange during the action potential in single atrial cells of the rabbit.","authors":"Y E Earm, W K Ho, I S So","doi":"10.1098/rspb.1990.0027","DOIUrl":"https://doi.org/10.1098/rspb.1990.0027","url":null,"abstract":"To investigate the underlying ionic mechanism of the late plateau phase of the action potential in rabbit atrium the whole-cell patch-clamp technique with intracellular perfusion was used. We recorded the inward current during repolarizations following a brief 2 ms depolarizing pulse to +40 mV from a holding potential of between -70 and -80 mV. The development of this current coincides with the onset of the late plateau phase of the action potential. Peak activation of the current occurs about 10 ms from the beginning of the depolarizing pulse, and it decays spontaneously with a slow timecourse. Its voltage dependency from -40 mV to +40 mV shows very steep activation (-40 to -20 mV) and shows almost the same maximum magnitude between -10 mV and +40 mV. This behaviour is quite different from that of the calcium current. The inward current and the late plateau phase of the action potential were both abolished by the application of 5 mM EGTA, 1 microM ryanodine and by reducing the Na+ gradient. The fully activated current-voltage relation of the inward current was plotted as the difference current before and after treatment with Ryanodine, Diltiazem, 20 mM Na+ inside or 30% Na+ outside and shows an exponential voltage dependence with the largest magnitude of the current occurring at negative potentials. The current-voltage (I-V) curve was well fitted by the Na-Ca exchange equation, i = A exp (-(1 - r)EF/RT). The results suggest that the inward current contributes to the generation of the late plateau phase of the rabbit atrial action potential, and is activated by intracellular calcium released from the sarcoplasmic reticulum. Sarcoplasmic reticulum calcium release appears to be triggered both by the membrane voltage and by the calcium current. It is concluded that the inward current is generated by Na-Ca exchange.","PeriodicalId":54561,"journal":{"name":"Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character","volume":"240 1297","pages":"61-81"},"PeriodicalIF":0.0,"publicationDate":"1990-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1098/rspb.1990.0027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12858849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 48

Spatial and temporal analysis of calcium-dependent electrical activity in guinea pig Purkinje cell dendrites. 豚鼠浦肯野细胞树突钙依赖性电活动的时空分析。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-05-22 DOI: 10.1098/rspb.1990.0032

W N Ross, N Lasser-Ross, R Werman

{"title":"Spatial and temporal analysis of calcium-dependent electrical activity in guinea pig Purkinje cell dendrites.","authors":"W N Ross, N Lasser-Ross, R Werman","doi":"10.1098/rspb.1990.0032","DOIUrl":"https://doi.org/10.1098/rspb.1990.0032","url":null,"abstract":"We have used the calcium indicator dye arsenazo III, together with a photodiode array, to record intracellular calcium changes simultaneously from all regions of individual guinea pig cerebellar Purkinje cells in slices. The optical signals, recorded with millisecond time resolution, are good indicators of calcium-dependent electrical events. For many cells the sensitivity of the recordings was high enough to detect signals from each array element without averaging. Consequently, it was possible to use these signals to follow the complex spatial and temporal patterns of plateau and spike potentials. Calcium entry corresponding to action potentials was detected from all parts of the dendritic field including the fine spiny branchlets, demonstrating that calcium action potentials spread over the entire arbor. Usually, the entire dendritic tree fired at once. But sometimes only restricted areas had signals at any one moment with transients detected in different regions at other times. In one cell, six separate zones were distinguished. These results show that calcium action potentials could be regenerative in some dendrites and could fail to propagate into others. Signals from plateau potentials were also detected from extensive areas in the dendritic field but were always smaller than those caused by a burst of action potentials.","PeriodicalId":54561,"journal":{"name":"Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character","volume":"240 1297","pages":"173-85"},"PeriodicalIF":0.0,"publicationDate":"1990-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1098/rspb.1990.0032","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13131267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 88

Passive bipedal running. 被动双足跑步。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-05-22 DOI: 10.1098/rspb.1990.0030

T McGeer

引用次数: 234

Ultrastructural localization of dystrophin in human muscle by using gold immunolabelling. 利用金免疫标记技术对肌营养不良蛋白的超微结构定位。

Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character Pub Date : 1990-05-22 DOI: 10.1098/rspb.1990.0034

M J Cullen, J Walsh, L V Nicholson, J B Harris

{"title":"Ultrastructural localization of dystrophin in human muscle by using gold immunolabelling.","authors":"M J Cullen, J Walsh, L V Nicholson, J B Harris","doi":"10.1098/rspb.1990.0034","DOIUrl":"https://doi.org/10.1098/rspb.1990.0034","url":null,"abstract":"Immunolabelling with a 5 nm gold probe was used to localize dystrophin at the ultrastructural level in human muscle. The primary antibody was monoclonal, raised against a segment (amino acids 1181-1388) from the rod domain of dystrophin. The antibody (Dy4/6D3) is specific for dystrophin and shows no immunoreactivity with any protein from mdx mouse muscle or from patients with a gene deletion spanning part of the molecule recognized by the antibody (Nicholson et al. 1989 a; England et al. 1990). Using this antibody, labelling was almost entirely confined to a narrow 75 nm rim at the periphery of the muscle fibres. Histograms of the distance from the gold probe to the cytoplasmic face of the plasma membrane and of the distance between gold probes (nearest neighbour in a plane parallel with the plasma membrane) displayed modes at approximately 15 nm and 120 nm, respectively. The distribution of the probe was the same in longitudinal and transverse sections of the muscle. These observations suggest that the rod portion of the dystrophin molecule is normally arranged close to the cytoplasmic face of the plasma membrane and that the molecules form an interconnecting network. Labelling was not associated with the transverse tubular system.","PeriodicalId":54561,"journal":{"name":"Proceedings of the Royal Society of London Series B-Containing Papers of Abiological Character","volume":"240 1297","pages":"197-210"},"PeriodicalIF":0.0,"publicationDate":"1990-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1098/rspb.1990.0034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13131268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 119