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Hearing Research Sep 2022Intra organ of Corti (OC) vibrations differ from those measured at the basilar membrane (BM), with higher amplitudes and a wide-band nonlinearity extending well below a...
Intra organ of Corti (OC) vibrations differ from those measured at the basilar membrane (BM), with higher amplitudes and a wide-band nonlinearity extending well below a region's best frequency. The vibrations are boosted by the cochlear amplifier, the active processes within the mammalian hearing organ, and are thus sensitive to metabolic or pharmacological manipulation. We introduced salicylate, a known blocker of outer hair cell (OHC) based electromotility, into the perilymphatic space by applying sodium salicylate onto the round window membrane. Vibration patterns of an area of the OC were mapped with phase sensitive optical coherence tomography before and after treatment; distortion product otoacoustic emissions (DPOAEs) were measured at similar times to assess the cochlear condition. Following treatment, all regions showed a loss of vibration amplitude and tuning while OHC-region vibrations retained their wide-band nonlinearity. OC vibrations, which had been relatively confined in a region including OHCs and extending to the BM at the outer pillar foot, became less confined with structures lateral to the OHCs sometimes exhibiting the highest amplitudes. Vibrations and DPOAEs could recover to baseline levels over approximately three hours post treatment. This article is part of the Special Issue Outer hair cell Edited by Joseph Santos-Sacchi and Kumar Navaratnam.
Topics: Animals; Basilar Membrane; Cochlea; Hair Cells, Auditory, Outer; Mammals; Organ of Corti; Salicylates; Vibration
PubMed: 34774368
DOI: 10.1016/j.heares.2021.108389 -
ELife Mar 2024A complete map of the external sense organs shows how fruit fly larvae detect different aspects of their environment.
A complete map of the external sense organs shows how fruit fly larvae detect different aspects of their environment.
Topics: Animals; Larva; Drosophila; Drosophila Proteins; Sense Organs; Emotions; Drosophila melanogaster
PubMed: 38456840
DOI: 10.7554/eLife.96708 -
Anatomical Record (Hoboken, N.J. : 2007) Mar 2022Marine mammals are a unique group of organisms that are secondarily adapted to the aquatic environment. Their specific lifestyle requires numerous adaptations of anatomy...
Marine mammals are a unique group of organisms that are secondarily adapted to the aquatic environment. Their specific lifestyle requires numerous adaptations of anatomy and physiology in general, and sensory physiology in particular. During the course of evolution, marine mammal senses changed to fit with the specific requirements of underwater sensing, while at the same time retaining aerial sensing to various degrees. In this special issue, state of the art science in the field of marine mammal sensory research is reported for representatives of all marine mammal groups, unfortunately with the exclusion of the polar bear. The articles focus on somatosensation of the glabrous skin of cetaceans and mechanoreception, including haptics, hydrodynamics, and acoustics, to chemoreception. Articles even deal with electroreception, highlighting that the bottlenose dolphin can perceive weak electric stimuli, and vision, indicating that harbor seals are able to derive temporal information from an optical stimulus. Altogether this special issue illustrates the diversity of research in the field regarding sensory systems, species, or experimental approaches. The strength of this special issue lies in the combination of carefully conducted anatomical studies paired with observations and behavioral studies attempting to relate "form" and "function" as well as in the many impulses and future avenues mentioned by numerous contributions.
Topics: Adaptation, Physiological; Animals; Caniformia; Cetacea; Mammals; Sense Organs
PubMed: 35077022
DOI: 10.1002/ar.24865 -
Journal of Comparative Physiology. A,... Mar 2021Spiders show a broad range of motions in addition to walking and running with their eight coordinated legs taking them towards their resources and away from danger. The... (Review)
Review
Spiders show a broad range of motions in addition to walking and running with their eight coordinated legs taking them towards their resources and away from danger. The usefulness of all these motions depends on the ability to control and adjust them to changing environmental conditions. A remarkable wealth of sensory receptors guarantees the necessary guidance. Many facets of such guidance have emerged from neuroethological research on the wandering spider Cupiennius salei and its allies, although sensori-motor control was not the main focus of this work. The present review may serve as a springboard for future studies aiming towards a more complete understanding of the spider's control of its different types of motion. Among the topics shortly addressed are the involvement of lyriform slit sensilla in path integration, muscle reflexes in the walking legs, the monitoring of joint movement, the neuromuscular control of body raising, the generation of vibratory courtship signals, the sensory guidance of the jump to flying prey and the triggering of spiderling dispersal behavior. Finally, the interaction of sensors on different legs in oriented turning behavior and that of the sensory systems for substrate vibration and medium flow are addressed.
Topics: Animals; Locomotion; Mechanoreceptors; Movement; Psychomotor Performance; Sense Organs; Sensilla; Sensory Receptor Cells; Spiders
PubMed: 33135112
DOI: 10.1007/s00359-020-01449-z -
International Journal of Molecular... Aug 2023Neurofibromatosis type 1 (NF1) is a rare inherited neurocutaneous disorder with a major impact on the skin, nervous system and eyes. The ocular diagnostic hallmarks of... (Review)
Review
Neurofibromatosis type 1 (NF1) is a rare inherited neurocutaneous disorder with a major impact on the skin, nervous system and eyes. The ocular diagnostic hallmarks of this disease include iris Lisch nodules, ocular and eyelid neurofibromas, eyelid café-au-lait spots and optic pathway gliomas (OPGs). In the last years, new manifestations have been identified in the ocular district in NF1 including choroidal abnormalities (CAs), hyperpigmented spots (HSs) and retinal vascular abnormalities (RVAs). Recent advances in multi-modality imaging in ophthalmology have allowed for the improved characterization of these clinical signs. Accordingly, CAs, easily detectable as bright patchy nodules on near-infrared imaging, have recently been added to the revised diagnostic criteria for NF1 due to their high specificity and sensitivity. Furthermore, subclinical alterations of the visual pathways, regardless of the presence of OPGs, have been recently described in NF1, with a primary role of neurofibromin in the myelination process. In this paper, we reviewed the latest progress in the understanding of choroidal and retinal abnormalities in NF1 patients. The clinical significance of the recently revised diagnostic criteria for NF1 is discussed along with new updates in molecular diagnosis. New insights into NF1-related neuro-ophthalmic manifestations are also provided based on electrophysiological and optical coherence tomography (OCT) studies.
Topics: Humans; Neurofibromatosis 1; Choroid; Neurofibromatoses; Skin; Eyelids
PubMed: 37686284
DOI: 10.3390/ijms241713481 -
EMBO Reports Dec 2016Stem cells have the remarkable ability to undergo proliferative symmetric divisions and self-renewing asymmetric divisions. Balancing of the two modes of division... (Review)
Review
Stem cells have the remarkable ability to undergo proliferative symmetric divisions and self-renewing asymmetric divisions. Balancing of the two modes of division sustains tissue morphogenesis and homeostasis. Asymmetric divisions of Drosophila neuroblasts (NBs) and sensory organ precursor (SOP) cells served as prototypes to learn what we consider now principles of asymmetric mitoses. They also provide initial evidence supporting the notion that aberrant symmetric divisions of stem cells could correlate with malignancy. However, transferring the molecular knowledge of circuits underlying asymmetry from flies to mammals has proven more challenging than expected. Several experimental approaches have been used to define asymmetry in mammalian systems, based on daughter cell fate, unequal partitioning of determinants and niche contacts, or proliferative potential. In this review, we aim to provide a critical evaluation of the assays used to establish the stem cell mode of division, with a particular focus on the mammary gland system. In this context, we will discuss the genetic alterations that impinge on the modality of stem cell division and their role in breast cancer development.
Topics: Animals; Asymmetric Cell Division; Cell Differentiation; Cell Lineage; Drosophila; Drosophila Proteins; Humans; Mammary Glands, Human; Mice; Mitosis; Neoplasms; Neurons; Sense Organs; Stem Cell Niche; Stem Cells
PubMed: 27872203
DOI: 10.15252/embr.201643021 -
Indian Journal of Otolaryngology and... Dec 2017Advancements in our understanding of vestibular physiology and how it is changes in different diseases have established that of the three therapeutic approaches to treat...
INTRODUCTION
Advancements in our understanding of vestibular physiology and how it is changes in different diseases have established that of the three therapeutic approaches to treat disorders of the vestibular system viz. pharmacotherapy, surgery and physical therapy, it is the later i.e., physical therapy which is the most efficacious modality in the management of balance disorders. The futility of vestibular sedatives in the correction of vestibular disorders and in the restoration of balance and the very limited role of surgery has now been recognised. Advancements in vestibulometry now enable us to localise any lesion in the vestibular system with utmost precision and also determine the exact cause of the balance disorder. The site of lesion and the specific organ that is defective can now be very precisely identified. Treatment modalities especially that for physical therapy hence have to be organ specific, and if possible, also disease specific.
AIMS AND OBJECTIVES
The study aims at evaluating the efficacy of physiotherapy in the management of balance disorders and also assesses the efficacy of organ targeted physical therapy, a new concept in restoring balance after vestibulometry has identified the offending organ.
MATERIALS AND METHODS
The study was conducted in the specialised physical therapy unit for balance and gait disorder patients which is a part of Vertigo and Deafness Clinic in Kolkata, India. Special instruments for physical therapy devised by the first author were used for stimulation of specific sense organs in the vestibular labyrinth that were found to be defective in vestibulometry. Specially made Virtual reality programs were used in patients suffering from psychogenic balance disorders. The pre and post therapy status was evaluated by different standard scales to assess balance and dizziness.
RESULTS
Very promising results were obtained. Organ targeted physiotherapy where defective sense organs were specifically stimulated showed remarkable improvement in different measures. Virtual reality exercises too showed very promising results in patients of psychogenic vertigo.
PubMed: 29238670
DOI: 10.1007/s12070-017-1236-9 -
The Journal of Experimental Biology Nov 2023Motion plays an essential role in sensory acquisition. From changing the position in which information can be acquired to fine-scale probing and active sensing, animals...
Motion plays an essential role in sensory acquisition. From changing the position in which information can be acquired to fine-scale probing and active sensing, animals actively control the way they interact with the environment. In olfaction, movement impacts the time and location of odour sampling as well as the flow of odour molecules around the olfactory organs. Employing a detailed spatiotemporal analysis, we investigated how insect antennae interact with the olfactory environment in a species with a well-studied olfactory system - the American cockroach. Cockroaches were tested in a wind-tunnel setup during the presentation of odours with different attractivity levels: colony extract, butanol and linalool. Our analysis revealed significant changes in antennal kinematics when odours were presented, including a shift towards the stream position, an increase in vertical movement and high-frequency local oscillations. Nevertheless, the antennal shifting occurred predominantly in a single antenna while the overall range covered by both antennae was maintained throughout. These findings hold true for both static and moving stimuli and were more pronounced for attractive odours. Furthermore, we found that upon odour encounter, there was an increase in the occurrence of high-frequency antennal sweeps and vertical strokes, which were shown to impact the olfactory environment's statistics directly. Our study lays out a tractable system for exploring the tight coupling between sensing and movement, in which antennal sweeps, in parallel to mammalian sniffing, are actively involved in facilitating odour capture and transport, generating odour intermittency in environments with low air movement where cockroaches dwell.
Topics: Animals; Smell; Periplaneta; Odorants; Cockroaches; Sense Organs; Arthropod Antennae; Mammals
PubMed: 37750327
DOI: 10.1242/jeb.245337 -
Developmental Dynamics : An Official... Jan 2023Sensory neurons of the head are the ones that transmit the information about the external world to our brain for its processing. Axons from cranial sensory neurons sense... (Review)
Review
Sensory neurons of the head are the ones that transmit the information about the external world to our brain for its processing. Axons from cranial sensory neurons sense different chemoattractant and chemorepulsive molecules during the journey and in the target tissue to establish the precise innervation with brain neurons and/or receptor cells. Here, we aim to unify and summarize the available information regarding molecular mechanisms guiding the different afferent sensory axons of the head. By putting the information together, we find the use of similar guidance cues in different sensory systems but in distinct combinations. In vertebrates, the number of genes in each family of guidance cues has suffered a great expansion in the genome, providing redundancy, and robustness. We also discuss recently published data involving the role of glia and mechanical forces in shaping the axon paths. Finally, we highlight the remaining questions to be addressed in the field.
Topics: Animals; Axon Guidance; Axons; Sensory Receptor Cells; Neuroglia; Sense Organs
PubMed: 35972036
DOI: 10.1002/dvdy.523 -
Annals of Anatomy = Anatomischer... Jun 2024In this manuscript, the structure of the human choroid is reviewed with emphasis of the macro- and microscopic anatomy including Bruch's membrane, choriocapillaris,... (Review)
Review
In this manuscript, the structure of the human choroid is reviewed with emphasis of the macro- and microscopic anatomy including Bruch's membrane, choriocapillaris, Sattler's and Haller's layer, and the suprachoroid. We here discuss the development of the choroid, as well as the question of choroidal lymphatics, and further the neuronal control of this tissue, as well as the pathologic angiogenesis. Wherever possible, functional aspects of the various structures are included and reviewed.
Topics: Humans; Choroid; Bruch Membrane
PubMed: 38432349
DOI: 10.1016/j.aanat.2024.152239