Plasticity of body axis polarity in Hydra regeneration under constraints.

One of the major events in animal morphogenesis is the emergence of a polar body axis. Here, we combine classic grafting techniques with live imaging to explore the plasticity of polarity determination during whole body regeneration in Hydra. Composite tissues are made by fusing two rings, excised from separate animals, in different configurations that vary in the polarity and original positions of the rings along the body axes of the parent animals.

Canalized Morphogenesis Driven by Inherited Tissue Asymmetries in Regeneration.

The emergence and stabilization of a body axis is a major step in animal morphogenesis, determining the symmetry of the body plan as well as its polarity. To advance our understanding of the emergence of body axis polarity, we study regenerating . Axis polarity is strongly memorized in regeneration even in small tissue segments.

Texture coarseness responsive neurons and their mapping in layer 2-3 of the rat barrel cortex in vivo.

Texture discrimination is a fundamental function of somatosensory systems, yet the manner by which texture is coded and spatially represented in the barrel cortex are largely unknown. Using in vivo two-photon calcium imaging in the rat barrel cortex during artificial whisking against different surface coarseness or controlled passive whisker vibrations simulating different coarseness, we show that layer 2-3 neurons within barrel boundaries differentially respond to specific texture coarsenesses, while only a minority of neurons responded monotonically with increased or decreased surface coarseness. Neurons with similar preferred texture coarseness were spatially clustered.

Nonlinear dendritic processing determines angular tuning of barrel cortex neurons in vivo.

Layer 4 neurons in primary sensory cortices receive direct sensory information from the external world. A general feature of these neurons is their selectivity to specific features of the sensory stimulation. Various theories try to explain the manner in which these neurons are driven by their incoming sensory information.