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Journal of Feline Medicine and Surgery Apr 2021The aim of this study was to determine if cats fed from a commercially advertised whisker-friendly dish vs their normal food dish would spend more time at the food dish,...
OBJECTIVES
The aim of this study was to determine if cats fed from a commercially advertised whisker-friendly dish vs their normal food dish would spend more time at the food dish, eat more and drop less food.
METHODS
Forty indoor cats were enrolled in the study. Owners fasted their cats for 12 h and fed them their normal measured amount of dry food in their normal dish. Owners filmed their cats eating for up to 5 mins, and measured how much food was eaten and dropped from the dish. Owners then switched to feeding their cats from a whisker-friendly dish for a 7-day transition period. Following this transition, owners were instructed to fast their cats for 12 h and then feed them their normal food from the new dish and film them eating, as previously described. The following day the owners offered food in both dishes to determine their cat's preference.
RESULTS
No evidence was found that eating from the whisker-friendly dish increased the amount of time spent eating ( = 0.8), decreased the amount of food dropped ( = 0.9) or increased the amount of food eaten ( = 0.7). The estimated probability for the cats to prefer the whisker-friendly dish was 0.74 with a 95% confidence interval.
CONCLUSIONS AND RELEVANCE
Cats fed from a whisker-friendly dish did not spend more time eating, drop less food or eat more food in a 5-min period. Some cats appeared to prefer the new whisker-friendly dish over their normal food dish. Overall, food dish-associated whisker stress did not affect the eating habits of the study cats.
Topics: Animals; Cats; Feeding Behavior; Surveys and Questionnaires; Vibrissae
PubMed: 32538246
DOI: 10.1177/1098612X20930190 -
The Journal of Neuroscience : the... Jun 2021Perception is an active process, requiring the integration of both proprioceptive and exteroceptive information. In the rat's vibrissal system, a classical model for...
Perception is an active process, requiring the integration of both proprioceptive and exteroceptive information. In the rat's vibrissal system, a classical model for active sensing, the relative contribution of the two information streams was previously studied at the peripheral, thalamic, and cortical levels. Contributions of brainstem neurons were only indirectly inferred for some trigeminal nuclei according to their thalamic projections. The current work addressed this knowledge gap by performing the first comparative study of the encoding of proprioceptive whisking and exteroceptive touch signals in the oralis (SpVo), interpolaris (SpVi), and paratrigeminal (Pa5) brainstem nuclei. We used artificial whisking in anesthetized male rats, which allows a systematic analysis of the relative contribution of the proprioceptive and exteroceptive information streams along the ascending pathways in the absence of motor or cognitive top-down modulations. We found that (1) neurons in the rostral and caudal parts of the SpVi convey whisking and touch information, respectively, as predicted by their thalamic projections; (2) neurons in the SpVo encode both whisking and (primarily) touch information; and (3) neurons of the Pa5 encode a complex combination of whisking and touch information. In particular, the Pa5 contains a relatively large fraction of neurons that are inhibited by active touch, a response observed so far only in the thalamus. Overall, our systematic characterization of afferent responses to active touch in the trigeminal brainstem approves the hypothesized functions of SpVi neurons and presents evidence that SpVo and Pa5 neurons are involved in the processing of active vibrissal touch. The present work constitutes the first comparative study of the encoding of proprioceptive (whisking) and exteroceptive (touch) information in the rat's brainstem trigeminal nuclei, the first stage of vibrissal processing in the CNS. It shows that (1) as expected, the rostral and caudal interpolaris neurons convey primarily whisking and touch information, respectively; (2) the oralis nucleus, whose function was previously unknown, encodes both whisking and (primarily) touch touch information; (3) a subtractive computation, reported at the thalamic level, already occurs at the brainstem level; and (4) a novel afferent pathway probably ascends via the paratrigeminal nucleus, encoding both proprioceptive and exteroceptive information.
Topics: Animals; Brain Stem; Male; Proprioception; Rats; Rats, Wistar; Touch Perception; Vibrissae
PubMed: 33893218
DOI: 10.1523/JNEUROSCI.1410-20.2021 -
Anatomical Record (Hoboken, N.J. : 2007) Mar 2022Most cetaceans are born with vibrissae but they can be lost or reduced in adulthood, especially in odontocetes. Despite this, some species of odontocetes have been found...
Most cetaceans are born with vibrissae but they can be lost or reduced in adulthood, especially in odontocetes. Despite this, some species of odontocetes have been found to have functioning vibrissal follicles (including the follicle itself and any remaining vibrissal hair shaft) that play a role in mechanoreception, proprioception and electroreception. This reveals a greater diversity of vibrissal function in odontocetes than in any other mammalian group. However, we know very little about vibrissal follicle form and function across the Cetacea. Here, we qualitatively describe the gross vibrissal follicle anatomy of fetuses of three species of cetaceans, including two odontocetes: Atlantic white-sided dolphin (Lagenorhynchus acutus), harbour porpoise (Phocoena phocoena), and one mysticete: minke whale (Balaenoptera acutorostrata), and compared our findings to previous anatomical descriptions. All three species had few, short vibrissae contained within a relatively simple, single-part follicle, lacking in muscles. However, we observed differences in vibrissal number, follicle size and shape, and innervation distribution between the species. While all three species had nerve fibers around the follicles, the vibrissal follicles of Balaenoptera acutorostrata were innervated by a deep vibrissal nerve, and the nerve fibers of the odontocetes studied were looser and more branched. For example, in Lagenorhynchus acutus, branches of nerve fibers travelled parallel to the follicle, and innervated more superficial areas, rather than just the base. Our anatomical descriptions lend support to the observation that vibrissal morphology is diverse in cetaceans, and is worth further investigation to fully explore links between form and function.
Topics: Animals; Cetacea; Dolphins; Hair Follicle; Vibrissae
PubMed: 34288543
DOI: 10.1002/ar.24714 -
Current Opinion in Neurobiology Dec 2020Animals can learn to use sensory stimuli to generate motor actions in order to obtain rewards. However, the precise neuronal circuits driving learning and execution of a... (Review)
Review
Animals can learn to use sensory stimuli to generate motor actions in order to obtain rewards. However, the precise neuronal circuits driving learning and execution of a specific goal-directed sensory-to-motor transformation remain to be elucidated. Here, we review progress in understanding the contribution of cortical neuronal circuits to a task in which head-restrained water-restricted mice learn to lick a reward spout in response to whisker deflection. We first examine 'innate' pathways for whisker sensory processing and licking motor control, and then discuss how these might become linked through reward-based learning, perhaps enabled by cholinergic-gated and dopaminergic-gated plasticity. The aim is to uncover the synaptically connected neuronal pathways that mediate reward-based learning and execution of a well-defined sensory-to-motor transformation.
Topics: Animals; Behavior, Animal; Goals; Mice; Reward; Sensation; Vibrissae
PubMed: 33065332
DOI: 10.1016/j.conb.2020.08.003 -
Communications Biology Jun 2023Behavior and innervation suggest a high tactile sensitivity of elephant trunks. To clarify the tactile trunk periphery we studied whiskers with the following findings....
Behavior and innervation suggest a high tactile sensitivity of elephant trunks. To clarify the tactile trunk periphery we studied whiskers with the following findings. Whisker density is high at the trunk tip and African savanna elephants have more trunk tip whiskers than Asian elephants. Adult elephants show striking lateralized whisker abrasion caused by lateralized trunk behavior. Elephant whiskers are thick and show little tapering. Whisker follicles are large, lack a ring sinus and their organization varies across the trunk. Follicles are innervated by ~90 axons from multiple nerves. Because elephants don't whisk, trunk movements determine whisker contacts. Whisker-arrays on the ventral trunk-ridge contact objects balanced on the ventral trunk. Trunk whiskers differ from the mobile, thin and tapered facial whiskers that sample peri-rostrum space symmetrically in many mammals. We suggest their distinctive features-being thick, non-tapered, lateralized and arranged in specific high-density arrays-evolved along with the manipulative capacities of the trunk.
Topics: Animals; Vibrissae; Elephants; Touch; Mammals; Movement
PubMed: 37291455
DOI: 10.1038/s42003-023-04945-5 -
International Journal of Molecular... Dec 2022Recovery of mimic function after facial nerve transection is poor. The successful regrowth of regenerating motor nerve fibers to reinnervate their targets is compromised... (Review)
Review
Recovery of mimic function after facial nerve transection is poor. The successful regrowth of regenerating motor nerve fibers to reinnervate their targets is compromised by (i) poor axonal navigation and excessive collateral branching, (ii) abnormal exchange of nerve impulses between adjacent regrowing axons, namely axonal crosstalk, and (iii) insufficient synaptic input to the axotomized facial motoneurons. As a result, axotomized motoneurons become hyperexcitable but unable to discharge. We review our findings, which have addressed the poor return of mimic function after facial nerve injuries, by testing the hypothesized detrimental component, and we propose that intensifying the trigeminal sensory input to axotomized and electrophysiologically silent facial motoneurons improves the specificity of the reinnervation of appropriate targets. We compared behavioral, functional, and morphological parameters after single reconstructive surgery of the facial nerve (or its buccal branch) with those obtained after identical facial nerve surgery, but combined with direct or indirect stimulation of the ipsilateral infraorbital nerve. We found that both methods of trigeminal sensory stimulation, i.e., stimulation of the vibrissal hairs and manual stimulation of the whisker pad, were beneficial for the outcome through improvement of the quality of target reinnervation and recovery of vibrissal motor performance.
Topics: Rats; Animals; Facial Nerve Injuries; Nerve Regeneration; Rats, Wistar; Facial Nerve; Vibrissae; Recovery of Function
PubMed: 36499425
DOI: 10.3390/ijms232315101 -
Frontiers in Neurology 2021Nerve injury resulting in muscle paralysis from trauma or surgery is a major medical problem. Repair of such injuries with existing nerve grafting and reconstructive...
Nerve injury resulting in muscle paralysis from trauma or surgery is a major medical problem. Repair of such injuries with existing nerve grafting and reconstructive techniques often results in less than optimal outcomes. After previously demonstrating significant return of function using muscle-nerve-muscle (MNM) grafting in a rat facial nerve model, this study compares a variant of the technique, muscle-nerve-nerve (MNN) neurotization to MNM and interposition (IP) nerve grafting. Thirty male rats were randomized into four groups (1) control with no intervention, (2) repair with IP grafts, (3) MNM grafts and (4) MNN grafts. All groups had the buccal and marginal mandibular branches of the right facial nerve resected. Return of vibrissae movement, orientation, and snout symmetry was measured over 16 weeks. Functional recovery and muscle atrophy were assessed and quantified. All interventions resulted in significant improvement in vibrissae movement and orientation as compared to the control group ( < 0.05). The MNM and MNN groups had significantly less time to forward vibrissae movement as compared to controls ( < 0.05), and a large number of animals in the MNN group had coordinated vibrissae movement at 16 weeks. MNN and IP grafts retained significantly more muscle mass as compared to control ( < 0.05). Thus, MNN grafting is a promising adjuvant or alternative technique for reanimation for patients with unilateral peripheral nerve injury who are not candidates for primary neurorrhaphy.
PubMed: 34956038
DOI: 10.3389/fneur.2021.723024 -
Frontiers in Systems Neuroscience 2019A key question in systems neuroscience is to identify how sensory stimuli are represented in neuronal activity, and how the activity of sensory neurons in turn is "read... (Review)
Review
A key question in systems neuroscience is to identify how sensory stimuli are represented in neuronal activity, and how the activity of sensory neurons in turn is "read out" by downstream neurons and give rise to behavior. The choice of a proper model system to address these questions, is therefore a crucial step. Over the past decade, the increasingly powerful array of experimental approaches that has become available in non-primate models (e.g., optogenetics and two-photon imaging) has spurred a renewed interest for the use of rodent models in systems neuroscience research. Here, I introduce the rodent whisker-mediated touch system as a structurally well-established and well-organized model system which, despite its simplicity, gives rise to complex behaviors. This system serves as a behaviorally efficient model system; known as nocturnal animals, along with their olfaction, rodents rely on their whisker-mediated touch system to collect information about their surrounding environment. Moreover, this system represents a well-studied circuitry with a somatotopic organization. At every stage of processing, one can identify anatomical and functional topographic maps of whiskers; "barrelettes" in the brainstem nuclei, "barreloids" in the sensory thalamus, and "barrels" in the cortex. This article provides a brief review on the basic anatomy and function of the whisker system in rodents.
PubMed: 31496942
DOI: 10.3389/fnsys.2019.00040 -
Current Biology : CB Jun 2022Consistent individual differences in behavior, or personality, may buffer populations against environmental changes. A long-term study of Galápagos sea lions reveals...
Consistent individual differences in behavior, or personality, may buffer populations against environmental changes. A long-term study of Galápagos sea lions reveals foraging polymorphisms with different levels of reproductive resilience as ocean temperatures increase.
Topics: Animals; Feeding Behavior; Personality; Sea Lions; Vibrissae
PubMed: 35671728
DOI: 10.1016/j.cub.2022.04.080 -
Current Research in Neurobiology 2022Most mammals have sensory tactile hairs, also known as whiskers or vibrissae. Traditionally, whiskers are associated with diverse survival skills, including tactile...
Most mammals have sensory tactile hairs, also known as whiskers or vibrissae. Traditionally, whiskers are associated with diverse survival skills, including tactile discrimination, distance assessment, food acquisition, gap crossing, and social interaction. Vibrissae functions are processed in the somatosensorial cortex, commonly referred to as the barrel cortex. Hence, most of the whisker-related research has been focused on this cortical region. However, increasing evidence indicates that the vibrissal system modulates several aspects of hippocampal physiology. This graphical review aims to summarize cumulative evidence indicating that whiskers regulate the neural function and cellularity in several hippocampal subfields. Interestingly, lack of whiskers notably affects neuronal firing in CA1 and CA3 hippocampal subfields, alters spatial mapping, impairs navigational skills, modifies cytoarchitecture, and reduces the adult neurogenesis in the dentate gyrus. This evidence extends our understanding of how whiskers are related to hippocampal function and offers insights to explore novel associations between whisker functions and neural plasticity in the hippocampus.
PubMed: 35647562
DOI: 10.1016/j.crneur.2022.100034