Tactile localisation: the function of active antennal movements in the crayfishCherax destructor

Abstract

Video recordings and single frame analysis were used to study the function of the second antennae of crayfish (Cherax destructor) as a sensory system in freely behaving animals. Walking crayfish move their antennae back and forth through horizontal angles of 100 degrees and more, relative to the body long axis. At rest, animals tend to hold their antennae at angular positions between 20 and 50 degrees. Movements of the two antennae are largely independent of each other. Before and during a turn of the body the ipsilateral antenna is moved into the direction of the turn. Solid objects are explored by repeatedly moving the antennae towards and across them. Both seeing and blinded crayfish can locate stationary objects following antennal contact. On antennal contact with a small novel object, a moving animal withdraws its antenna and attacks the object. When the antenna of a blinded crayfish is lightly touched with a brush the animal turns and attacks the point of stimulation. The direction taken and the distance covered during an attack can be correlated with: the angle at which the antenna is held at the moment of contact and the distance along the antennal flagellum at which the stimulus is applied. From behavioural evidence we conclude that crayfish use information about the angular position of their antennae and about the position of stimulated mechanoreceptors along the antennal flagellum to locate objects in their environment. We suggest ways in which an active tactile system-like the crayfish's antennae--could supply animals with information about the three-dimensional layout of their environment.

Mechanical processing via passive dynamic properties of the cockroach antenna can facilitate control during rapid running

“…3, Table 1). The implications for sensing are that antenna mechanics could condition sensing during high-speed tactile navigation with the position of the point of bend acting as a one-dimensional sensory map, as originally proposed in P. americana (Camhi and Johnson, 1999) and in the crayfish Cherax destructor (Zeil et al, 1985;Sandeman, 1989). Especially during rapid running where neural delays can impose severe constraints on control (Cowan et al, 2006), sensory mapping conditioned by mechanics could be a very desirable feature for simplifying sensing and control.…”

“…Specifically, antennal bending properties that include how the point of bend (relative to the base of the antenna) and/or the contact point shift as the antenna bends, have been linked directly to body-to-wall distance discrimination during high-speed wall following (Camhi and Johnson, 1999). As cockroaches (Camhi and Johnson, 1999) and crayfish (Zeil et al, 1985;Sandeman, 1989) move closer to an object, the straight portion of their antenna (region from base of antenna to bend) shortens as the bend 'moves' towards the base and the flagellum's contact point with the wall (relative to the tip) increases. Camhi and Johnson (Camhi and Johnson, 1999) proposed that the point of bend or the contact point could constitute a onedimensional map along the length of the antenna that could provide a cue to induce a change in body angle, thus a form of morphological or mechanical processing.…”

Orienting and avoidance turning are precisely computed by the predatory sea-slugPleurobranchaea californicaMcFarland

“…What is more, hungry animals may avoid food items with which they have had a previous negative experience, such as induced sickness or distress from effects of strong prey defenses (Garcia and Koelling, 1966;Mpitsos and Collins, 1975;Gillette et al, 2000). Diverse studies have elucidated the computations for directional behavior in arthropods and fish (Murphey, 1971;Levi and Camhi, 2000;Zeil et al, 1985;Eaton and Emberly, 1991), but few have similarly examined elements of foraging behavior in molluscs (but see Teyke et al, 1990). Further, to our knowledge none have quantitatively studied the interactions of sensation and internal state for which these model systems are most useful.…”

“…Thus, in the present study, we tested the effects of appetitive and only moderately aversive chemotactile stimuli. We adapted procedures for quantitatively relating stimulus site to turn response in other species (Murphey, 1971;Zeil et al, 1985;Teyke et al, 1990;Levi and Camhi, 2000) for use with Pleurobranchaea. Our findings indicate that the angle of the turn response to a punctate chemotactile stimulus applied to the animal's oral veil is precisely computed on the basis of stimulus site and strength, while the turn direction is a function of both stimulus modality and satiation state.…”

Effects of the Radical Scavenger, Water Soluble Protein from Broad Beans on Lipofuscin, Cathepsin B, Cell Growth in Human Lung Fibroblasts

“…The voluntary movement of antenna has been described in some insects, flies (Horn and Kessler, 1975), crickets (Honegger, 1981;Horseman et al, 1997), locusts (Saager and Gewecke, 1989), bees (Erber et al, 1993), beetles (Pelletier and McLeod, 1994), ants (Ehmer and Gronenberg, 1997a, b) and stick insects (Dürr et al, 2001), and also for crustacean crayfishes (Sandeman and Wilkens, 1983;Zeil et al, 1985), in relation with their specific behaviors. In the cockroach P. americana, antennal deflections induced by the sex and aggregation pheromones have been examined (Rust et al, 1976), where both antennae first responded to the pheromones with outward deflections regardless of the direction of odor source, and then turned antennae toward the source mainly by the head movement.…”