Orientation to vibrations in sand by the nocturnal scorpionParuroctonus mesaensis: Mechanism of target localization

Tactile Information Processing for the Orientation Behaviour of Sand Scorpions

“…In this paper, we investigate the role of inhibition mechanism and synaptic delays in the network configuration among the command neurons to determine the direction of a vibration source. Also we will re-visit the triad inhibition hypothesis suggested by Brownell and Farley (1979). Relevant works were presented in the paper (Kim, 2006a(Kim, , 2006b).…”

“…The sand scorpions show their orientation behaviour of positioning themselves directly towards their prey and then run into the prey when there is a vibration disturbance caused by the prey. According to the biological researches (Brownell & Farley, 1979, Brownell, 1984, it is presumed that the sand scorpions respond to Rayleigh waves, surface waves of sand, to detect the direction of a vibration source and possibly longitudinal vibrations to estimate the distance. Especially, the time delay between arrival of a vibration signal at the BCSS sense organs is an important cue to determine the direction of their prey (Brownell & Farley, 1979).…”

“…According to the biological researches (Brownell & Farley, 1979, Brownell, 1984, it is presumed that the sand scorpions respond to Rayleigh waves, surface waves of sand, to detect the direction of a vibration source and possibly longitudinal vibrations to estimate the distance. Especially, the time delay between arrival of a vibration signal at the BCSS sense organs is an important cue to determine the direction of their prey (Brownell & Farley, 1979). The central nervous system should process stimulus-locked neuron firings of the sense organs on their eight legs to induce the orientation behaviour.…”

“…In fact, arachnids have sensory projections to the central nervous system for each leg (Babu & Barth, 1989, Anton & Barth, 1993. Previously Brownell and Farley (1979) suggested that eight command neurons (or eight clusters of neurons in the brain) accumulate neuron firings from mechanoreceptors on the eight legs of scorpions, respectively and also interact each other with triad inhibitions. According to the triad inhibition hypothesis, early arrival of vibration stimulus to mechanoreceptors on a leg excites the corresponding command neuron and the command neuron subsequently inhibits three command neurons on the opposite side.…”

“…This inhibition mechanism forms an appropriate tuning curve of neuron firings for the resource direction. Brownell and Farley (1979) built this conceptual model with triad inhibitions for interaction over the eight receptor neurons (command neurons) and later Stuezl et al, (2001) tested the hypothesis with a neuronal model. Triad inhibition mechanism over a stimulus vibration showed a good agreement with the real orientation data of sand scorpions.…”