Eusocial insects, mostly Hymenoptera, have evolved unique colonial lifestyles that rely on the perception of social context mainly through pheromones, and chemoreceptors are hypothesized to have played important adaptive roles in the evolution of sociality. However, because chemoreceptor repertoires have been characterized in few social insects and their solitary relatives, a comprehensive exam...

effects of acute systemic hypoxia on the cardiovascular system (cys) and respiration of spontaneously breathing cats were studied in two conditions. 1): hypoxic air (6-8% 02 in n2) was given to the animal to induce systemic hypoxia for 20 minutes. hyperventilation at this condition lowered arterial c02 tension (pac02 hypocapnia). 2): in the second run, induction of hypocapnia was prevented by a...

Escherichia coli and Salmonella enterica are models for many experiments in molecular biology including chemotaxis, and most of the results obtained with one organism have been generalized to another. While most components of the chemotaxis pathway are strongly conserved between the two species, Salmonella genomes contain some chemoreceptors and an additional protein, CheV, that are not found i...

Peripheral chemoreceptors (carotid and aortic bodies) detect changes in arterial blood oxygen and initiate reflexes that are important for maintaining homeostasis during hypoxemia. This mini-review summarizes the importance of peripheral chemoreceptor reflexes in various physiological and pathophysiological conditions. Carotid bodies are important for eliciting hypoxic ventilatory stimulation i...

The chemosensory complexes in Escherichia coli are localized predominantly in large aggregates at one or both of the cell poles, however, neither the role of the polar localization nor the role of the clustering is understood. In E. coli, the two classes of chemoreceptors or transducers, high- and low-abundance, differ in their ability to support chemotaxis when expressed as the sole chemorecep...

The major objective of this review is to evaluate existing information and reach conclusions regarding whether there is interaction between P(CO(2))/H(+) stimulation of carotid (peripheral) and intracranial (central) chemoreceptors. Interaction is defined as a ventilatory response to simultaneous changes in the degree of Pco2/H(+) stimulation of both chemoreceptors that is greater (hyperadditiv...

Forster HV, Smith CA. Contributions of central and peripheral chemoreceptors to the ventilatory response to CO2/H . J Appl Physiol 108: 989–994, 2010. First published January 14, 2010; doi:10.1152/japplphysiol.01059.2009.—The major objective of this review is to evaluate existing information and reach conclusions regarding whether there is interaction between PCO2/H stimulation of carotid (peri...

Chemoreceptors are key components of the high-performance signal transduction system that controls bacterial chemotaxis. Chemoreceptors are typically localized in a cluster at the cell pole, where interactions among the receptors in the cluster are thought to contribute to the high sensitivity, wide dynamic range, and precise adaptation of the signaling system. Previous structural and genomic s...