Modeling spatial filters of primary visual cortex Seres, I.; Marczell, Z.; Fomin, T. ...
Proceedings of 1994 IEEE International Conference on Neural Networks (ICNN'94),
1994, Volume:
4
Conference Proceeding
Here we address the issue of unsupervised learning for primary visual cortex (V/sub 1/) formation. According to the most popular model, single cells in the primary visual cortex are spatio-temporal ...filters. Receptive fields of simple cells can be subdivided into separate excitatory and inhibitory regions, which can be described by a Gaussian-weighted sine wave. These cells transform the fairly broadband input, arriving from lower visual areas, into bandlimited information in the orientation, spatial frequency and temporal frequency domains. The existence of relatively independent spatial frequency and orientation selective channels in the visual system has been shown by human psychophysics. Inhibitory interactions between neighbouring channels were suggested to perform more complex image-analysis, like texture processing or detecting long and smooth contours. Our goal is to introduce a model that imposes minimal assumptions and beyond producing spatial filters can account for some psychophysical results with the help of nonlinearities. Efforts to design self-organizing neurocontrol led to spatial filters. Here, we shall try to identify these filters with the local filters of V/sub 1/.< >
The elastin-laminin receptor Fülöp, T; Jacob, M P; Wallach, J ...
Journal de la Société de biologie,
2001, Volume:
195, Issue:
2
Journal Article
Elastin is a major component of the extracellular matrix. Elastin peptides derived from its degradation are present in human sera. Elastin peptides induce on fibroblasts, phagocytic cells, ...lymphocytes, smooth muscle cells and endothelial cells, a variety of biological effects mediated by the elastin-laminin receptor which has been demonstrated to be present on the membrane of these cells. The transduction pathway of the ELR receptor involves the activation of phospholipase C (PLC) by a pertussis toxin sensitive G-protein. PLC induces the production of inositol trisphosphate (IP3) leading to the increase of the intracellular free calcium on one hand, and of diacylglycerol (DAG) which stimulates the translocation to the membrane of PKC leading to the phosphorylation of members of the MAPK family, such as p42/p44 MAPK. Considering the multiple biological effects of ELR the elucidation of the complexity of the signaling pathways will help to better modulate it, mainly in pathological situations such as atherosclerosis.
A case of idiopathic cholestasis Maroş, T; Seres-Sturm, M T; Keresztessy, A ...
Morphologie et embryologie,
1977 Apr-Jun, Volume:
23, Issue:
2
Journal Article
