Structure and physiology of the locust femoral chordotonal organ

The insecticide pymetrozine selectively affects chordotonal mechanoreceptors

“…The response of the fCO to joint movement, including position-and velocity-sensitivity (Burns, 1974;, is abolished by pymetrozine. A tonic spike discharge may be present, although usually transiently just after pymetrozine application.…”

“…To stimulate the fCO (Burns, 1974;Field and Pflüger, 1989), a window was cut into the anterior dorsal surface of the femur, sparing the attachment sites of tibia muscles as far as possible.…”

“…All physiological types of receptor cells were affected, those responding to joint position, to the velocity of joint movement (exemplified in Fig.·6) or to a combination of these parameters (e.g. Burns, 1974;Field and Pflüger, 1989; detailed analyses for the stick insect in Büschges, 1994). This held true for stimulus velocities between 108 and 2730· m·s -1 (18-455·deg.·s -1 ) and stimulus amplitudes between 240 and 480· m (40-80°).…”

Chordotonal organs in hemipteran insects: unique peripheral structures but conserved central organization revealed by comparative neuroanatomy

“…This is reasonable given that measurements of local mechanical properties of the body surface, which have transmission properties that are different from those of substrate vibrations, are particularly important for small insects to attain directional information (Cocroft et al 2000). The location, cell clustering manner, cellular displacements according to tibial positions, and dendritic morphologies collectively suggest that the ventral and dorsal scoloparia in stink bugs are homologous to the ventral and dorsal scoloparia, respectively, in stick insects (Kittmann and Schmitz 1992) and crickets (Nowel et al 1995;Nishino 2000) and the distal and proximal scoloparia, respectively, in locusts (Burns 1974). The latter scoloparium has been suggested to participate preferentially in vibration detection rather than mediation of slow and large tibial movements (Field and (Shelton et al 1992) and crickets (Nowel et al 1995).…”

Motor output characterizing thanatosis in the cricketGryllus bimaculatus

“…Activation of the slow exciters occurs largely through persistence of the postural resistance reflex (Field and Coles, 1994) mediated by the femoral chordotonal organ (FCO), which contains position-sensitive sensory neurones as well as velocity-and accelerationsensitive neurones (Burns, 1974;Matheson, 1990Matheson, , 1992. This was revealed by an ablation study in which removal of sensory cells in the ventral part of the FCO scoloparia led to a severe loss of flexor muscle tonus in the respective leg during thanatosis (Nishino et al, 1999).…”