Comprehensive measurement of neural activity remains challenging due to the large numbers of neurons in each brain area. We used volumetric two-photon imaging in mice expressing GCaMP6s and nuclear red fluorescent proteins to sample activity in 75% of superficial barrel cortex neurons across the relevant cortical columns, approximately 12,000 neurons per animal, during performance of a single w...

The barrel cortex and whisker thalamus preferentially respond to whisker movements during REM sleep in infant rats. Understanding why the brain tunes into sensory signals while it's tuned out in sleep may provide clues about the functions of REM sleep.

Rodents use active whisker movements to explore their environment. The "slip hypothesis" of whisker-related tactile perception entails that short-lived kinematic events (abrupt whisker movements, called "slips", due to bioelastic whisker properties that occur during active touch of textures) carry the decisive texture information. Supporting this hypothesis, previous studies have shown that sli...

The role of cortical activity in experience-dependent cortical plasticity was studied in the rat barrel cortex. Plasticity was induced by depriving every other whisker in a chessboard pattern, which is known to cause depression of responses to deprived whisker stimulation and potentiation of responses to spared whisker stimulation. Postsynaptic activity was blocked by muscimol released from elv...

Resin composites currently available are not suitable for use as large stress-bearing posterior restorations involving cusps due to their tendencies toward excessive fracture and wear. The glass fillers in composites provide only limited reinforcement because of the brittleness and low strength of glass. The aim of the present study was to reinforce dental resins with ceramic single-crystalline...

We examine the e€ect of 10 vol.% TiB whisker reinforcement on transformation superplasticity of Ti±6Al±4V, induced by thermal cycling about the a/b phase transformation range of the matrix under a uniaxial tensile stress. During superplastic deformation, the whiskers gradually align along the external loading axis, as measured by electron back-scattering diffraction of deformed specimens. The c...

The ability of rats to use their whiskers for fine tactile discrimination rivals that of humans using their fingertips. Rats perform discriminations rapidly and accurately while palpating the environment with their whiskers. This suggests that whisker deflections produce a robust and reliable neural code. Whisker primary afferents respond with highly reproducible temporal spike patterns to tran...

This paper discusses some theoretical aspects in deforming nano-whiskers of monocrystalline copper by uniaxial tension. With the aid of the molecular dynamics analysis, the present study revealed that the behaviour of a nano-whisker is very sensitive to its size, crystal orientation and geometry. The most stable surface is with (111) atomic structure and the most reliable whisker for testing is...

Many rodents explore their environment by rhythmically palpating objects with their mystacial whiskers. These rhythmic whisker movements ("whisking"; 5-9 Hz) are thought to be regulated by an unknown brainstem central pattern generator (CPG). We tested the hypothesis that serotonin (5-HT) inputs to whisking facial motoneurons (wFMNs) are part of this CPG. In response to exogenous serotonin, wFM...

Tactile information is actively acquired and processed in the brain through concerted interactions between movement and sensation. Somatosensory input is often the result of self-generated movement during the active touch of objects, and conversely, sensory information is used to refine motor control. There must therefore be important interactions between sensory and motor pathways, which we ch...