Pharmacological profiling of stretch activated channels in proprioceptive neurons.

Proprioception in mammals and invertebrates occurs through stretch activated ion channels (SACs) localized in sensory endings. In mammals, the primary organs for proprioception are the intrafusal muscle spindles embedded within extrafusal muscle. In invertebrates there are varied types of sensory organs, from chordotonal organs spanning joints to muscle receptor organs (MRO) which are analogous to the mammalian muscle spindles that monitor stretch of muscle fibers. A subset of SACs are the PIEZO channels. They are comprised of a distinct type of protein sequence and are similar among species, from mammals to invertebrates. We screened several new agents (YODA 1, JEDI 2, OB 1 and DOOKU) which have been identified to act on SACs of the PIEZO 1 subtype. JEDI 2 increased activity in the crayfish MRO but not the crab chordotonal organs. The SACs of the crustacean proprioceptors have not been satisfactorily pharmacologically classified, nor has their molecular makeup been identified. We screened these pharmacological agents on model sensory organs in crustaceans to learn more about their subtype classification and compare genomic profiles of related species.