This work has identified properties of such a sensor such as long time constant and opened up the comparative domain, with searches for other receptors in different animal groups. Key questions remain regarding the detailed organization of the transduction mechanism, and how such long lasting signals are processed and integrated in the nervous sytem. The mechanism seems to involve differential compression of cuticular thread hairs in the statocyst which are linked to paired mechanoreceptors by a cuticular chorda. The sealed statocyst sac appears to reduce the sensitivity of the system. The ways in which the thread hairs process the information are being investigated in isolated statocyst systems and in whole tethered crabs with implanted electrodes.
Techniques involved are conventional extracellular recording from nerves near the brain of the crab.
Teflon coated silver wires 0.125mm diameter are inserted through a 0.3mm hole in the carapace and sealed with cyanoacrylate glue when correctly positioned. Identified interneurones, known physiologically and anatomically from previous dye injection studies with intracellular electrodes have been recorded during pressure cycles. Hydrostatic pressure is controlled with a computer controlled stepper motor system which allows sinusoidal and ramp pressure functions with periods from 10 minutes to several days and amplitudes up to 0.5 bar.