Chronic stimulation of a mystacial whisker follicle for 24 h induces structural and functional changes in layer IV of the corresponding barrel, with an insertion of new inhibitory synapses on spines and a depression of neuronal responses to the stimulated whisker. Under urethane anesthesia, we analyzed how sensory responses of single units are affected in layer IV and layers II & III of the sti...

The lateral facial nucleus is the sole output structure whose neuronal activity leads to whisker movements. To understand how single facial nucleus neurons contribute to whisker movement we combined single-cell stimulation and high-precision whisker tracking. Half of the 44 stimulated neurons gave rise to fast whisker protraction or retraction movement, whereas no stimulation-evoked movements c...

Cells in the rat barrel cortex exhibit stimulus-specific response properties. To understand the network mechanism of direction selectivity in response to facial whisker deflection, we examined direction selectivity of neuronal responses to single- and multi-whisker stimulations. In the case of regular-spiking units, i.e., putative excitatory cells, direction preferences were quite similar betwe...

Rats use active, rhythmic movements of their whiskers to acquire tactile information about three-dimensional object features. There are no receptors along the length of the whisker; therefore all tactile information must be mechanically transduced back to receptors at the whisker base. This raises the question: how might the rat determine the radial contact position of an object along the whisk...

Voigts J, Sakmann B, Celikel T. Unsupervised whisker tracking in unrestrained behaving animals. J Neurophysiol 100: 504–515, 2008. First published May 7, 2008; doi:10.1152/jn.00012.2008. Understanding how whisker-based tactile information is represented in the nervous system requires quantification of sensory input and observation of neural activity during whisking and whisker touch. Chronic el...

After half a century of research, the sensory features coded by neurons of the rodent barrel cortex remain poorly understood. Still, views of the sensory representation of whisker information are increasingly shifting from a labeled line representation of single-whisker deflections to a selectivity for specific elements of the complex statistics of the multi-whisker deflection patterns that tak...

A micromechanical model was developed to predict the elastic moduli of hydroxyapatite (HA) whisker reinforced polymer biocomposites based upon the elastic properties of each phase and the reinforcement volume fraction, morphology, and preferred orientation. The effects of the HA whisker volume fraction, morphology, and orientation distribution were investigated by comparing model predictions wi...

Trimming all whiskers except two on one side of an adult rat's face results in cortical plasticity in which the spared whiskers, D2 and one D-row surround whisker (either D1 or D3), evoked responses containing more spikes than the response evoked by the cut whisker (called whisker pairing plasticity). Previously we have reported that acetylcholine (ACh) depletion in cortex prevents surround D-r...

28 29 The function of rodents’ whisker somatosensory system is to transform tactile cues, in the form of 30 vibrissa vibrations, into neuronal responses. It is well established that rodents can detect numerous 31 tactile stimuli and tell them apart. However, the transformation of tactile stimuli obtained through 32 whisker movements to neuronal responses is not well-understood. Here we examine ...

1. The rat whisker-to-barrel system was used to investigate the variability and interhemispheric asymmetry in the functional organization of primary somatosensory cortex as assessed with intrinsic signal optical imaging. The areal extent of whisker D1 functional representation was determined for both the left and right barrel cortex of each of 10 adult male rats. The average size of whisker D1 ...