27 research outputs found
Ultrastructure of an identified array of growth cones and possible substrates for guidance in the embryonic medicinal leech, Hirudo medicinalis
Differentiation of the body wall musculature in Macrostomum hystricinum marinum and Hoploplana inquilina (Plathelminthes), as models for muscle development in lower Spiralia
Interactions between the tonic and cyclic postural motor programs in the crayfish abdomen
Neural control of a cyclic postural behavior in the crayfish,Procambarus clarkii: the pattern-initiating interneurons
Heat induced developmental uncoupling of mesoderm from ectoderm and endoderm germ layer derivatives during Artemia postembryonic segmentation
Synaptic interactions between neurons involved in the production of abdominal posture in crayfish
Synaptic responses produced in lobster abdominal postural motor neurons by mechanical stimulation of the swimmeret
Coding characteristics of spiking local interneurons during imposed limb movements in the locust
The performance of adaptive behavior relies on continuous sensory feedback to produce relevant modifications to central motor patterns. The femoral chordotonal organ (FeCO) of the legs of the desert locust monitors the movements of the tibia about the femoro-tibial joint. A ventral midline population of spiking local interneurons in the metathoracic ganglia integrates inputs from the FeCO. We used a Wiener kernel cross-correlation method combined with a Gaussian white noise stimulation of the FeCO to completely characterize and model the output dynamics of the ventral midline population of interneurons. A wide range of responses were observed, and interneurons could be classified into three broad groups that received excitatory and inhibitory or principally inhibitory or excitatory synaptic inputs from the FeCO. Interneurons that received mixed inputs also had the greatest linear responses but primarily responded to extension of the tibia and were mostly sensitive to stimulus velocity. Interneurons that received principally inhibitory inputs were sensitive to extension and to joint position. A small group of interneurons received purely excitatory synaptic inputs and were also sensitive to tibial extension. In addition to capturing the linear and nonlinear dynamics of this population of interneurons, first- and second-order Wiener kernels revealed that the dynamics of the interneurons in the population were graded and formed a spectrum of responses whereby the activity of many cells appeared to be required to adequately describe a particular stimulus characteristic, typical of population coding