Impulse responses in bacterial chemotaxis Export

@article{1982Block, abstract = {The chemotactic behavior of Escherichia coli has been studied by exposing cells tethered by a single flagellum to pulses of chemicals delivered iontophoretically. Normally, wild-type cells spin alternately clockwise and counterclockwise, changing their direction on the average approximately once per second. When cells were exposed to a very brief diffusive wave of attractant, the probability of spinning counterclockwise quickly peaked, then fell below the prestimulus value, returning to baseline within a few seconds; repellent responses were similar but inverted. The width of the response indicates that cells integrate sensory inputs over a period of seconds, while the biphasic character implies that they also take time derivates of these inputs. The sensory system is maximally tuned to concentration changes that occur over a span of approximately 2 sec, an interval over which changes normally occur when cells swim in spatial gradients; it is optimized to extract information from signals subject to statistical fluctuation. Impulse responses of cells defective in methylation were similar to those of wild-type cells, but did not fall as far below the baseline, indicating a partial defect in adaptation. Impulse responses of cheZ mutants were aberrant, indicating a serious defect in excitation.}, author = {Block, S.}, citeulike-article-id = {4730678}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/0092-8674(82)90421-4}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/0092-8674(82)90421-4}, doi = {10.1016/0092-8674(82)90421-4}, issn = {00928674}, journal = {Cell}, keywords = {bacterial, chemotaxis, filter, impulse}, month = {November}, number = {1}, pages = {215--226}, posted-at = {2009-06-03 09:45:02}, priority = {2}, title = {Impulse responses in bacterial chemotaxis}, url = {http://dx.doi.org/10.1016/0092-8674(82)90421-4}, volume = {31}, year = {1982} }

TY - JOUR ID - 1982Block L3 - citeulike-article-id:4730678 N2 - The chemotactic behavior of Escherichia coli has been studied by exposing cells tethered by a single flagellum to pulses of chemicals delivered iontophoretically. Normally, wild-type cells spin alternately clockwise and counterclockwise, changing their direction on the average approximately once per second. When cells were exposed to a very brief diffusive wave of attractant, the probability of spinning counterclockwise quickly peaked, then fell below the prestimulus value, returning to baseline within a few seconds; repellent responses were similar but inverted. The width of the response indicates that cells integrate sensory inputs over a period of seconds, while the biphasic character implies that they also take time derivates of these inputs. The sensory system is maximally tuned to concentration changes that occur over a span of approximately 2 sec, an interval over which changes normally occur when cells swim in spatial gradients; it is optimized to extract information from signals subject to statistical fluctuation. Impulse responses of cells defective in methylation were similar to those of wild-type cells, but did not fall as far below the baseline, indicating a partial defect in adaptation. Impulse responses of cheZ mutants were aberrant, indicating a serious defect in excitation. IS - 1 JF - Cell SN - 00928674 EP - 226 TI - Impulse responses in bacterial chemotaxis VL - 31 SP - 215 KW - bacterial KW - chemotaxis KW - filter KW - impulse AU - Block, S PY - 1982/11// UR - http://dx.doi.org/10.1016/0092-8674(82)90421-4 ER -