Novel, whisker-dependent texture discrimination task for mice.

Many mammals use their mystacial vibrissae to palpate objects in their environment and encode information such as size, shape and texture. We have developed a novel method to assess the sensitivity with which mice can discriminate textures using their mystacial vibrissae. Our texture discrimination task can be performed within 3 days, requiring approximately 1 h of handling time, per subject, over the entire testing period. No appetitive or aversive training is required. We have demonstrated that this novel texture discrimination task is dependent on intact mystacial vibrissae and can be performed by both young (2-month old) and older (6-month old) C57BL/6 mice. The parameters of the task can be adjusted to assess the sensitivity of mice using a gradient of textures with different roughness. We have developed a novel, efficient method to assess whisker-mediated texture discrimination in mice.

Increased mobility and stem-cell proliferation rate in Dugesia tigrina induced by 880nm light emitting diode.

The therapeutic effects elicited by photobiostimulation in the near infrared range may be associated with increased proliferation rate of particular cell-types. The present study utilized commercial light emitting diodes to investigate the effects of low-level near-infrared radiation on the proliferation rate of stem cells in amputated planarian. Whole and amputated animals were exposed to either ambient diurnal lighting, darkness, white light, red light, or near-infrared (880 nm) light. Irradiation was consistent for the duration of the experiments and was provided using commercial 5mm light emitting diodes (∼1.0 mW/m(2) in power density and ∼0.01 J/cm(2) in radiant exposure). Compared to other groups amputated planarian exposed to near-infrared displayed increased mobility by the 3rd day of exposure (F((4,26))=4.31, p<0.04, η(2)=41%). Higher densities of stem cells were measured in these worms 84 h post injury (F((4,72))=4.78, p<0.01, η(2)=21%). These findings suggest that non-coherent light sources with power-densities about 1000 times lower than contemporary low-power laser settings remain effective in generating photobiostimulation effects and warrants further investigation on stem-cell proliferation induced by near-infrared light emitting diodes.