Chemoreceptor Cells in Aquatic Invertebrates: Peripheral Mechanisms of Chemical Signal Processing in Decapod Crustaceans

Abstract

The sensory capabilities of any animal are determined by a sequential set of physical and biological filters that regulate which environmental disturbances will stimulate the receptive surface of the animal. The environment itself is the first filter as it transmits physical or chemical disturbances from one or another source. The animal’s sense organs contain additional physical filters that select—each with its own degree of specificity—which part of the disturbances will have best access to the receptor membrane. Subsequent filtering occurs at the level of receptor cells and at each next level of the CNS. Environmental disturbances that alter the activity of receptor cells are called stimuli: they include disturbances that trigger molecular mechanisms, such as adaptation in the cell without necessarily causing it to fire nerve impulses or other means of information coding. Subsequent interneuronal steps of information processing are all based on neural signals that code certain aspects of the original stimuli.