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Scientific Reports Mar 2021Multisensory integration of auditory and tactile information occurs already at the level of the cochlear nucleus. Rodents use their whiskers for tactile perception to...
Multisensory integration of auditory and tactile information occurs already at the level of the cochlear nucleus. Rodents use their whiskers for tactile perception to guide them in their exploration of the world. As nocturnal animals with relatively poor vision, audiotactile interactions are of great importance for this species. Here, the influence of whisker deflections on sound-evoked spiking in the cochlear nucleus was investigated in vivo in anesthetized mice. Multichannel, silicon-probe electrophysiological recordings were obtained from both the dorsal and ventral cochlear nucleus. Whisker deflections evoked an increased spiking activity in fusiform cells of the dorsal cochlear nucleus and t-stellate cells in ventral cochlear nucleus, whereas bushy cells in the ventral cochlear nucleus showed a more variable response. The response to broadband noise stimulation increased in fusiform cells and primary-like bushy cells when the sound stimulation was preceded (~ 20 ms) by whisker stimulation. Multi-sensory integration of auditory and whisker input can thus occur already in this early brainstem nucleus, emphasizing the importance of early integration of auditory and somatosensory information.
Topics: Acoustic Stimulation; Animals; Cochlear Nucleus; Electric Stimulation; Evoked Potentials, Somatosensory; Male; Mice; Mice, Inbred C57BL; Neural Inhibition; Neurons; Sensation; Vibrissae
PubMed: 33767295
DOI: 10.1038/s41598-021-86236-9 -
Current Biology : CB Nov 2023New work reveals whisker landmark coding in the retrosplenial cortex of mice, broadening our understanding of multisensory spatial cognition, contextual processing, and...
New work reveals whisker landmark coding in the retrosplenial cortex of mice, broadening our understanding of multisensory spatial cognition, contextual processing, and spatial predictive coding.
Topics: Animals; Mice; Cognition; Gyrus Cinguli; Spatial Navigation; Touch; Touch Perception; Vibrissae
PubMed: 37989098
DOI: 10.1016/j.cub.2023.10.018 -
Proceedings of the National Academy of... Mar 2021For neuronal circuits in the brain to mature, necessary synapses must be maintained and redundant synapses eliminated through experience-dependent mechanisms. However,...
For neuronal circuits in the brain to mature, necessary synapses must be maintained and redundant synapses eliminated through experience-dependent mechanisms. However, the functional differentiation of these synapse types during the refinement process remains elusive. Here, we addressed this issue by distinct labeling and direct recordings of presynaptic terminals fated for survival and for elimination in the somatosensory thalamus. At surviving terminals, the number of total releasable vesicles was first enlarged, and then calcium channels and fast-releasing synaptic vesicles were tightly coupled in an experience-dependent manner. By contrast, transmitter release mechanisms did not mature at terminals fated for elimination, irrespective of sensory experience. Nonetheless, terminals fated for survival and for elimination both exhibited developmental shortening of action potential waveforms that was experience independent. Thus, we dissected experience-dependent and -independent developmental maturation processes of surviving and eliminated presynaptic terminals during neuronal circuit refinement.
Topics: Action Potentials; Afferent Pathways; Animals; Calcium Channels; Mice; Nerve Net; Neurotransmitter Agents; Presynaptic Terminals; Synaptic Vesicles; Trigeminal Nuclei; Ventral Thalamic Nuclei; Vibrissae
PubMed: 33688051
DOI: 10.1073/pnas.2022423118 -
Zhongguo Xiu Fu Chong Jian Wai Ke Za... Sep 2023To investigate the preparation and properties of the novel silica (SiO )/hydroxyapatite (HAP) whiskers porous ceramics scaffold.
OBJECTIVE
To investigate the preparation and properties of the novel silica (SiO )/hydroxyapatite (HAP) whiskers porous ceramics scaffold.
METHODS
The HAP whiskers were modified by the SiO microspheres using the Stöber method. Three types of SiO /HAP whiskers were fabricated under different factors (for the No.1 samples, the content of tetraethoxysilane, stirring time, calcination temperature, and soaking time were 10 mL, 12 hours, 560℃, and 0.5 hours, respectively; and in the No.2 samples, those were 15 mL, 24 hours, 650℃, and 2 hours, respectively; while those in the No.3 samples were 20 mL, 48 hours, 750℃, and 4 hours, respectively). The phase and morphology of the self-made HAP whisker and 3 types of SiO /HAP whiskers were detected by the X-ray diffraction analysis and scanning electron microscopy. Taken the self-made HAP whisker and 3 types of SiO /HAP whiskers as raw materials, various porous ceramic materials were prepared using the mechanical foaming method combined with extrusion molding method, and the low-temperature heat treatment. The pore structure of porous ceramics was observed by scanning electron microscopy. Its porosity and pore size distribution were measured. And further the axial compressive strength was measured, and the biodegradability was detected by simulated body fluid. Cell counting kit 8 method was used to conduct cytotoxicity experiments on the extract of porous ceramics.
RESULTS
The SiO microspheres modified HAP whiskers and its porous ceramic materials were prepared successfully, respectively. In the SiO /HAP whiskers, the amorphous SiO microspheres with a diameter of 200 nm, uniform distribution and good adhesion were attached to the surface of the whiskers, and the number of microspheres was controllable. The apparent porosity of the porous ceramic scaffold was about 78%, and its pore structure was composed of neatly arranged longitudinal through-holes and a large number of micro/nano through-holes. Compared with HAP whisker porous ceramic, the axial compressive strength of the SiO /HAP whisker porous ceramics could reach 1.0 MPa, which increased the strength by nearly 4 times. Among them, the axial compressive strength of the No.2 SiO /HAP whisker porous ceramic was the highest. The SiO microspheres attached to the surface of the whiskers could provide sites for the deposition of apatite. With the content of SiO microspheres increased, the deposition rate of apatite accelerated. The cytotoxicity level of the prepared porous ceramics ranged from 0 to 1, without cytotoxicity.
CONCLUSION
SiO /HAP whisker porous ceramics have good biological activity, high porosity, three-dimensional complex pore structure, good axial compressive strength, and no cytotoxicity, which make it a promising scaffold material for bone tissue engineering.
Topics: Animals; Durapatite; Porosity; Vibrissae; Apatites; Ceramics; Silicon Dioxide
PubMed: 37718429
DOI: 10.7507/1002-1892.202304073 -
BioRxiv : the Preprint Server For... Dec 2023High-resolution awake mouse fMRI remains challenging despite extensive efforts to address motion-induced artifacts and stress. This study introduces an implantable...
High-resolution awake mouse fMRI remains challenging despite extensive efforts to address motion-induced artifacts and stress. This study introduces an implantable radiofrequency (RF) surface coil design that minimizes image distortion caused by the air/tissue interface of mouse brains while simultaneously serving as a headpost for fixation during scanning. Using a 14T scanner, high-resolution fMRI enabled brain-wide functional mapping of visual and vibrissa stimulation at 100×100×200μm resolution with a 2s per frame sampling rate. Besides activated ascending visual and vibrissa pathways, robust BOLD responses were detected in the anterior cingulate cortex upon visual stimulation and spread through the ventral retrosplenial area (VRA) with vibrissa air-puff stimulation, demonstrating higher-order sensory processing in association cortices of awake mice. In particular, the rapid hemodynamic responses in VRA upon vibrissa stimulation showed a strong correlation with the hippocampus, thalamus, and prefrontal cortical areas. Cross-correlation analysis with designated VRA responses revealed early positive BOLD signals at the contralateral barrel cortex (BC) occurring 2 seconds prior to the air-puff in awake mice with repetitive stimulation, which was not detectable with the randomized stimulation paradigm. This early BC activation indicated learned anticipation through the vibrissa system and association cortices in awake mice under continuous training of repetitive air-puff stimulation. This work establishes a high-resolution awake mouse fMRI platform, enabling brain-wide functional mapping of sensory signal processing in higher association cortical areas.
PubMed: 38106227
DOI: 10.1101/2023.12.08.570803 -
Annals of Anatomy = Anatomischer... Jan 2020Animal models of nerve function have been subject to extensive study in order to understand and investigate methods which may improve axon regeneration and promote... (Review)
Review
Animal models of nerve function have been subject to extensive study in order to understand and investigate methods which may improve axon regeneration and promote functional outcomes following nerve injury and repair. As the facial nerve is a cranial nerve, there is mounting evidence that cranial nerve regeneration differs from peripheral, and outcome models specifically addressing the facial nerve are required. Murine models are the most commonly utilized, with a variety of methods employed to measure the actions of whisking, eye closure, or ear movement as indicators of facial nerve regeneration. Each method of measurement is reviewed in terms of validity, strengths, limitations, and the specific outcome data provided. The authors propose that prior to choosing an outcome model, the goals and objectives of a planned study should be well defined, as various outcome measures may be useful depending on the information which is desired. The aim of this paper, therefore, is to provide the reader with a concise review which may facilitate project design.
Topics: Animals; Ear, External; Electromyography; Eyelids; Facial Nerve; Mice; Microscopy, Confocal; Microscopy, Fluorescence; Models, Animal; Nerve Regeneration; Rats; Spectrophotometry, Infrared; Vibrissae; Video Recording
PubMed: 31394169
DOI: 10.1016/j.aanat.2019.07.011 -
Neuroscience Jul 2022In Robo3cKO mouse brain, rhombomere 3-derived trigeminal principal nucleus (PrV) neurons project bilaterally to the somatosensory thalamus. As a consequence,...
In Robo3cKO mouse brain, rhombomere 3-derived trigeminal principal nucleus (PrV) neurons project bilaterally to the somatosensory thalamus. As a consequence, whisker-specific neural modules (barreloids and barrels) representing whiskers on both sides of the face develop in the sensory thalamus and the primary somatosensory cortex. We examined the morphological complexity of layer 4 barrel cells, their postsynaptic partners in layer 3, and functional specificity of layer 3 pyramidal cells. Layer 4 spiny stellate cells form much smaller barrels and their dendritic fields are more focalized and less complex compared to controls, while layer 3 pyramidal cells did not show notable differences. Using in vivo 2-photon imaging of a genetically encoded fluorescent [Ca] sensor, we visualized neural activity in the normal and Robo3cKO barrel cortex in response to ipsi- and contralateral single whisker stimulation. Layer 3 neurons in control animals responded only to their contralateral whiskers, while in the mutant cortex layer 3 pyramidal neurons showed both ipsi- and contralateral whisker responses. These results indicate that bilateral whisker map inputs stimulate different but neighboring groups of layer 3 neurons which normally relay contralateral whisker-specific information to other cortical areas.
Topics: Animals; Mice; Neurons; Pyramidal Cells; Somatosensory Cortex; Thalamus; Vibrissae
PubMed: 35598701
DOI: 10.1016/j.neuroscience.2022.05.018 -
Current Opinion in Neurobiology Feb 2020In natural environments, choices frequently must be made on the basis of complex and ambiguous streams of sensory input. There are advantages inherent to rapid decision... (Review)
Review
In natural environments, choices frequently must be made on the basis of complex and ambiguous streams of sensory input. There are advantages inherent to rapid decision making. Choices are better grounded, however, if information is acquired and accumulated over time. In primate visual motion perception, sensory evidence is accumulated up to a limit, at which point the brain commits to a choice. Recalling the models evoked for primate visual perception, recent studies in the rat vibrissal sensorimotor system, using a number of behavioral paradigms, show that perceptual decision making is characterized by the integration of sensory evidence over time. In this integrative process, vibrissal primary somatosensory cortex (vS1 and vS2) act not as the integrator, but as the distributor of sensory information to downstream regions.
Topics: Animals; Decision Making; Motion Perception; Rats; Somatosensory Cortex; Vibrissae
PubMed: 31816523
DOI: 10.1016/j.conb.2019.11.012 -
Cerebral Cortex (New York, N.Y. : 1991) Jul 2022Abnormal tactile response is an integral feature of Autism Spectrum Disorders (ASDs), and hypo-responsiveness to tactile stimuli is often associated with the severity of...
Abnormal tactile response is an integral feature of Autism Spectrum Disorders (ASDs), and hypo-responsiveness to tactile stimuli is often associated with the severity of ASDs core symptoms. Patients with Phelan-McDermid syndrome (PMS), caused by mutations in the SHANK3 gene, show ASD-like symptoms associated with aberrant tactile responses. The neural underpinnings of these abnormalities are still poorly understood. Here we investigated, in Shank3b-/- adult mice, the neural substrates of whisker-guided behaviors, a key component of rodents' interaction with the surrounding environment. We assessed whisker-dependent behaviors in Shank3b-/- adult mice and age-matched controls, using the textured novel object recognition (tNORT) and whisker nuisance (WN) test. Shank3b-/- mice showed deficits in whisker-dependent texture discrimination in tNORT and behavioral hypo-responsiveness to repetitive whisker stimulation in WN. Sensory hypo-responsiveness was accompanied by a significantly reduced activation of the primary somatosensory cortex (S1) and hippocampus, as measured by c-fos mRNA induction, a proxy of neuronal activity following whisker stimulation. Moreover, resting-state fMRI showed a significantly reduced S1-hippocampal connectivity in Shank3b mutants, in the absence of altered connectivity between S1 and other somatosensory areas. Impaired crosstalk between hippocampus and S1 might underlie Shank3b-/- hypo-reactivity to whisker-dependent cues, highlighting a potentially generalizable somatosensory dysfunction in ASD.
Topics: Animals; Chromosome Disorders; Disease Models, Animal; Hippocampus; Mice; Mice, Knockout; Microfilament Proteins; Nerve Tissue Proteins; Somatosensory Cortex; Vibrissae
PubMed: 34791077
DOI: 10.1093/cercor/bhab399 -
Journal of Neuroscience Methods Feb 2020Previous studies have measured whisker movements and locomotion to characterise mouse models of neurodegenerative disease. However, these studies have always been... (Review)
Review
BACKGROUND
Previous studies have measured whisker movements and locomotion to characterise mouse models of neurodegenerative disease. However, these studies have always been completed in isolation, and do not involve standardized procedures for comparisons across multiple mouse models and background strains.
NEW METHOD
We present a standard method for conducting whisker movement and locomotion studies, by carrying out qualitative scoring and quantitative measurement of whisker movements from high-speed video footage of mouse models of Amyotrophic Lateral Sclerosis, Huntington's disease, Parkinson's disease, Alzheimer's disease, Cerebellar Ataxia, Somatosensory Cortex Development and Ischemic stroke.
RESULTS
Sex, background strain, source breeder and genotype all affected whisker movements. All mouse models, apart from Parkinson's disease, revealed differences in whisker movements during locomotion. R6/2 CAG250 Huntington's disease mice had the strongest behavioural phenotype. Robo3R-CKO and RIM-DKOSert mouse models have abnormal somatosensory cortex development and revealed significant changes in whisker movements during object exploration.
COMPARISON WITH EXISTING METHOD(S)
Our results have good agreement with past studies, which indicates the robustness and reliability of measuring whisking. We recommend that differences in whisker movements of mice with motor deficits can be captured in open field arenas, but that mice with impairments to sensory or cognitive functioning should also be filmed investigating objects. Scoring clips qualitatively before tracking will help to structure later analyses.
CONCLUSIONS
Studying whisker movements provides a quantitative measure of sensing, motor control and exploration. However, the effect of background strain, sex and age on whisker movements needs to be better understood.
Topics: Animals; Cognition; Locomotion; Mice; Neurodegenerative Diseases; Reproducibility of Results; Somatosensory Cortex; Vibrissae
PubMed: 31785300
DOI: 10.1016/j.jneumeth.2019.108532