The Matrix: A new tool for probing the whisker-to-barrel system with natural stimuli

CNRS, Unité de Neurosciences, Information et Complexité (UNIC), 1 avenue de la Terrasse, 91190 Gif sur Yvette, France.
Journal of Neuroscience Methods (Impact Factor: 2.05). 03/2010; 189(1):65-74. DOI: 10.1016/j.jneumeth.2010.03.020
Source: PubMed


The whisker to barrel system in rodents has become one of the major models for the study of sensory processing. Several tens of whiskers (or vibrissae) are distributed in a regular manner on both sides of the snout. Many tactile discrimination tasks using this system need multiple contacts with more than one whisker to be solved. With the aim of mimicking those multi-whisker stimuli during electrophysiological recordings, we developed a novel mechanical stimulator composed of 24 independent multi-directional piezoelectric benders adapted to the five rows and the five caudal arcs of the rat whisker pad. The most widely used technology for producing mechanical deflections of the whiskers is based on piezoelectric benders that display a non-linear behavior when driven with high frequency input commands and, if not compensated, show high unwanted ringing at particular resonance frequencies. If not corrected, this non-linear behavior precludes the application of high frequency deflections and the study of cortical responses to behaviorally relevant stimuli. To cope with the ringing problem, a mechanical and a software based solutions have been developed. With these corrections, the upper bound of the linear range of the bender is increased to 1 kHz. This new device allows the controlled delivery of large scale natural patterns of whisker deflections characterized by rapid high frequency vibrations of multiple whiskers.

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Available from: Luc Estebanez, Oct 06, 2015
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    • "We used sparse noise stimuli applied via a nine-whisker stimulator (Jacob et al., 2010) to map receptive fields (Figures 3A and 3B). Examples of LV receptive fields evaluated using peristimulus time histograms (PSTH) and whisker-evoked postsynaptic potentials (wPSP) are shown in Figure 3C (neurons 2 and 4 are D-row deprived). "
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    ABSTRACT: Most functional plasticity studies in the cortex have focused on layers (L) II/III and IV, whereas relatively little is known of LV. Structural measurements of dendritic spines in vivo suggest some specialization among LV cell subtypes. We therefore studied experience-dependent plasticity in the barrel cortex using intracellular recordings to distinguish regular spiking (RS) and intrinsic bursting (IB) subtypes. Postsynaptic potentials and suprathreshold responses in vivo revealed a remarkable dichotomy in RS and IB cell plasticity; spared whisker potentiation occurred in IB but not RS cells while deprived whisker depression occurred in RS but not IB cells. Similar RS/IB differences were found in the LII/III to V connections in brain slices. Modeling studies showed that subthreshold changes predicted the suprathreshold changes. These studies demonstrate the major functional partition of plasticity within a single cortical layer and reveal the LII/III to LV connection as a major excitatory locus of cortical plasticity.
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    • "A recently developed whisker stimulation matrix based on piezoelectric benders (Jacob et al. 2010) was used to deflect independently the 24 most caudal whiskers of the right whisker pad (Fig. 1A). Whiskers were trimmed to 10-mm length and were inserted 3 mm into small plastic tubes of calibrated diameter glued on each bender. "
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