scholarly journals Cortical GABAergic Interneurons in Cross-Modal Plasticity following Early Blindness

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Sébastien Desgent ◽  
Maurice Ptito

Early loss of a given sensory input in mammals causes anatomical and functional modifications in the brain via a process called cross-modal plasticity. In the past four decades, several animal models have illuminated our understanding of the biological substrates involved in cross-modal plasticity. Progressively, studies are now starting to emphasise on cell-specific mechanisms that may be responsible for this intermodal sensory plasticity. Inhibitory interneurons expressing γ-aminobutyric acid (GABA) play an important role in maintaining the appropriate dynamic range of cortical excitation, in critical periods of developmental plasticity, in receptive field refinement, and in treatment of sensory information reaching the cerebral cortex. The diverse interneuron population is very sensitive to sensory experience during development. GABAergic neurons are therefore well suited to act as a gate for mediating cross-modal plasticity. This paper attempts to highlight the links between early sensory deprivation, cortical GABAergic interneuron alterations, and cross-modal plasticity, discuss its implications, and further provide insights for future research in the field.

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 797-797
Author(s):  
Emmanuel Garcia Morales ◽  
Nicholas Reed

Abstract Sensory impairment is prevalent among older adults and may increase risk for delirium via mechanisms including sensory deprivation and poor communication which may result in confusion and agitation. In the Medicare Current Beneficiary Study (MCBS), delirium was measured using a validated algorithm of claims data. Sensory impairment was defined as any self-reported trouble hearing or seeing, with the use of aids, and was categorized as no impairment, hearing impairment only (HI), vision impairment only (VI), and dual sensory impairment (DSI). Among, 3,240 hospitalized participants in 2016-2017, 346 (10.7%) experienced delirium. In a model adjusted for socio-demographic and health characteristics, those with HI only, VI only, and DSI had 0.84 (95% CI: 0.6-1.3), 1.1 (95% CI 0.7-1.7), and 1.5 (95% CI 1.0-2.1) times the odds of experiencing delirium compared to those without sensory impairment. Future research should focus on mechanisms underlying association and determine the impact of treatment of sensory loss.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily T. Wood ◽  
Kaitlin K. Cummings ◽  
Jiwon Jung ◽  
Genevieve Patterson ◽  
Nana Okada ◽  
...  

AbstractSensory over-responsivity (SOR), extreme sensitivity to or avoidance of sensory stimuli (e.g., scratchy fabrics, loud sounds), is a highly prevalent and impairing feature of neurodevelopmental disorders such as autism spectrum disorders (ASD), anxiety, and ADHD. Previous studies have found overactive brain responses and reduced modulation of thalamocortical connectivity in response to mildly aversive sensory stimulation in ASD. These findings suggest altered thalamic sensory gating which could be associated with an excitatory/inhibitory neurochemical imbalance, but such thalamic neurochemistry has never been examined in relation to SOR. Here we utilized magnetic resonance spectroscopy and resting-state functional magnetic resonance imaging to examine the relationship between thalamic and somatosensory cortex inhibitory (gamma-aminobutyric acid, GABA) and excitatory (glutamate) neurochemicals with the intrinsic functional connectivity of those regions in 35 ASD and 35 typically developing pediatric subjects. Although there were no diagnostic group differences in neurochemical concentrations in either region, within the ASD group, SOR severity correlated negatively with thalamic GABA (r = −0.48, p < 0.05) and positively with somatosensory glutamate (r = 0.68, p < 0.01). Further, in the ASD group, thalamic GABA concentration predicted altered connectivity with regions previously implicated in SOR. These variations in GABA and associated network connectivity in the ASD group highlight the potential role of GABA as a mechanism underlying individual differences in SOR, a major source of phenotypic heterogeneity in ASD. In ASD, abnormalities of the thalamic neurochemical balance could interfere with the thalamic role in integrating, relaying, and inhibiting attention to sensory information. These results have implications for future research and GABA-modulating pharmacologic interventions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Géraldine Fauville ◽  
Anna C. M. Queiroz ◽  
Erika S. Woolsey ◽  
Jonathan W. Kelly ◽  
Jeremy N. Bailenson

AbstractResearch about vection (illusory self-motion) has investigated a wide range of sensory cues and employed various methods and equipment, including use of virtual reality (VR). However, there is currently no research in the field of vection on the impact of floating in water while experiencing VR. Aquatic immersion presents a new and interesting method to potentially enhance vection by reducing conflicting sensory information that is usually experienced when standing or sitting on a stable surface. This study compares vection, visually induced motion sickness, and presence among participants experiencing VR while standing on the ground or floating in water. Results show that vection was significantly enhanced for the participants in the Water condition, whose judgments of self-displacement were larger than those of participants in the Ground condition. No differences in visually induced motion sickness or presence were found between conditions. We discuss the implication of this new type of VR experience for the fields of VR and vection while also discussing future research questions that emerge from our findings.


Author(s):  
Muhammed Jamsheer K ◽  
Manoj Kumar ◽  
Vibha Srivastava

AbstractThe Snf1-related protein kinase 1 (SnRK1) is the plant homolog of the heterotrimeric AMP-activated protein kinase/sucrose non-fermenting 1 (AMPK/Snf1), which works as a major regulator of growth under nutrient-limiting conditions in eukaryotes. Along with its conserved role as a master regulator of sugar starvation responses, SnRK1 is involved in controlling the developmental plasticity and resilience under diverse environmental conditions in plants. In this review, through mining and analyzing the interactome and phosphoproteome data of SnRK1, we are highlighting its role in fundamental cellular processes such as gene regulation, protein synthesis, primary metabolism, protein trafficking, nutrient homeostasis, and autophagy. Along with the well-characterized molecular interaction in SnRK1 signaling, our analysis highlights several unchartered regions of SnRK1 signaling in plants such as its possible communication with chromatin remodelers, histone modifiers, and inositol phosphate signaling. We also discuss potential reciprocal interactions of SnRK1 signaling with other signaling pathways and cellular processes, which could be involved in maintaining flexibility and homeostasis under different environmental conditions. Overall, this review provides a comprehensive overview of the SnRK1 signaling network in plants and suggests many novel directions for future research.


Check List ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 701-727 ◽  
Author(s):  
Rodrigo Brincalepe Salvador ◽  
Barbara Mizumo Tomotani ◽  
Colin Miskelly ◽  
Susan M. Waugh

Callaeidae (wattlebirds) and Notiomystidae (stitchbirds) are New Zealand-endemic sister-taxa; while widespread before human settlement, they subsequently became critically endangered or extinct. Aside from presently managed populations, information about them is scarce and actual specimens even scarcer. Herein, we provide a snapshot of these families’ historical distribution during the critical periods of European settlement and expansion in New Zealand (19th and early-20th centuries), exploring new data and insights resulting from this approach. We include an extensive catalogue of worldwide museum specimens to facilitate future research. We report the last known record/specimen of huia Heteralocha acutirostris (Gould, 1837) and late 19th century specimens of North Island saddleback Philesturnus rufusater (Lesson, 1828) from Cuvier Island that confirm its occurrence there. We failed to find specimens of North Island saddleback and stitchbird Notiomystis cincta (du Bus de Gisignies, 1839) (with one and two exceptions, respectively) from named locations on the mainland.


Author(s):  
Aarthi Madhavan ◽  
Nicole M. Etter

Purpose Both the enjoyment of foods and safe swallowing revolve around incorporating multiple streams of sensory feedback to form a positive sensory experience; these include information about the taste, smell, texture, temperature, and even the sight of food. Traditional swallowing assessment and treatment paradigms have primarily focused on the motor aspects of swallowing. However, sensory information is vital for not only enjoying foods while eating but also coordinating safe and efficient swallow behaviors. The purpose of this clinical focus article is to discuss the clinical importance of sensation in swallowing evaluation and intervention. Conclusions During their clinical assessments of swallowing, speech-language pathologists are already documenting the functional results of oropharyngeal sensorimotor impairments (e.g., residue). A combination of sensory and motor aspects is already integrated within current behavioral treatment strategies for dysphagia. Focused attention to the salient sensory features of swallowing has the potential to improve swallowing evaluation and intervention efforts. A discussion of potential future research in improved measurement and documentation of altered sensation is provided.


2021 ◽  
Vol 101 (1) ◽  
pp. 353-415
Author(s):  
Jochen F. Staiger ◽  
Carl C. H. Petersen

The array of whiskers on the snout provides rodents with tactile sensory information relating to the size, shape and texture of objects in their immediate environment. Rodents can use their whiskers to detect stimuli, distinguish textures, locate objects and navigate. Important aspects of whisker sensation are thought to result from neuronal computations in the whisker somatosensory cortex (wS1). Each whisker is individually represented in the somatotopic map of wS1 by an anatomical unit named a ‘barrel’ (hence also called barrel cortex). This allows precise investigation of sensory processing in the context of a well-defined map. Here, we first review the signaling pathways from the whiskers to wS1, and then discuss current understanding of the various types of excitatory and inhibitory neurons present within wS1. Different classes of cells can be defined according to anatomical, electrophysiological and molecular features. The synaptic connectivity of neurons within local wS1 microcircuits, as well as their long-range interactions and the impact of neuromodulators, are beginning to be understood. Recent technological progress has allowed cell-type-specific connectivity to be related to cell-type-specific activity during whisker-related behaviors. An important goal for future research is to obtain a causal and mechanistic understanding of how selected aspects of tactile sensory information are processed by specific types of neurons in the synaptically connected neuronal networks of wS1 and signaled to downstream brain areas, thus contributing to sensory-guided decision-making.


2015 ◽  
Vol 20 (4) ◽  
pp. 273-282 ◽  
Author(s):  
Hannah Brotherton ◽  
Christopher J. Plack ◽  
Michael Maslin ◽  
Roland Schaette ◽  
Kevin J. Munro

Naturally occurring stimuli can vary over several orders of magnitude and may exceed the dynamic range of sensory neurons. As a result, sensory systems adapt their sensitivity by changing their responsiveness or ‘gain'. While many peripheral adaptation processes are rapid, slow adaptation processes have been observed in response to sensory deprivation or elevated stimulation. This adaptation process alters neural gain in order to adjust the basic operating point of sensory processing. In the auditory system, abnormally high neural gain may result in higher spontaneous and/or stimulus-evoked neural firing rates, and this may have the unintended consequence of presenting as tinnitus and/or sound intolerance, respectively. Therefore, a better understanding of neural gain, in health and disease, may lead to more effective treatments for these aberrant auditory perceptions. This review provides a concise summary of (i) evidence for changes in neural gain in the auditory system of animals, (ii) physiological and perceptual changes in adult human listeners following an acute period of enhanced acoustic stimulation and/or deprivation, (iii) physiological evidence of excessive neural gain in tinnitus and hyperacusis patients, and (iv) the relevance of neural gain in the clinical treatment of tinnitus and hyperacusis.


2016 ◽  
Vol 116 (4) ◽  
pp. 1765-1784 ◽  
Author(s):  
Pedro Gabrielle Vieira ◽  
João Paulo Machado de Sousa ◽  
Jerome Baron

The neuronal representation of luminance contrast has not been thoroughly studied in birds. Here we present a detailed quantitative analysis of the contrast response of 120 individual neurons recorded from the visual wulst of awake burrowing owls ( Athene cunicularia). Stimuli were sine-wave gratings presented within the cell classical receptive field and optimized in terms of eye preference, direction of drift, and spatiotemporal frequency. As contrast intensity was increased from zero to near 100%, most cells exhibited a monotonic response profile with a compressive, at times saturating, nonlinearity at higher contrasts. However, contrast response functions were found to have a highly variable shape across cells. With the view to capture a systematic trend in the data, we assessed the performance of four plausible models (linear, power, logarithmic, and hyperbolic ratio) using classical goodness-of-fit measures and more rigorous statistical tools for multimodel inferences based on the Akaike information criterion. From this analysis, we conclude that a high degree of model uncertainty is present in our data, meaning that no single descriptor is able on its own to capture the heterogeneous nature of single-unit contrast responses in the wulst. We further show that the generalizability of the hyperbolic ratio model established, for example, in the primary visual cortex of cats and monkeys is not tenable in the owl wulst mainly because most neurons in this area have a much wider dynamic range that starts at low contrast. The challenge for future research will be to understand the functional implications of these findings.


Author(s):  
Erin M. Rhinehart

AbstractThe burgeoning field of metabolic reproduction regulation has been gaining momentum due to highly frequent discoveries of new neuroendocrine factors regulating both energy balance and reproduction. Universally throughout the animal kingdom, energy deficits inhibit the reproductive axis, which demonstrates that reproduction is acutely sensitive to fuel availability. Entrainment of reproductive efforts with energy availability is especially critical for females because they expend large amounts of energy on gestation and lactation. Research has identified an assortment of both central and peripheral factors involved in the metabolic regulation of reproduction. From an evolutionary perspective, these mechanisms likely evolved to optimize reproductive fitness in an environment with an unpredictable food supply and regular bouts of famine. To be effective, however, the mechanisms responsible for the metabolic regulation of reproduction must also retain developmental plasticity to allow organisms to adapt their reproductive strategies to their particular niche. In particular, the prenatal environment has emerged as a critical developmental window for programming the mechanisms responsible for the metabolic control of reproduction. This review will discuss the current knowledge about hormonal and molecular mechanisms that entrain reproduction with prevailing energy availability. In addition, it will provide an evolutionary, human life-history framework to assist in the interpretation of findings on gestational programming of the female reproductive function, with a focus on pubertal timing as an example. Future research should aim to shed light on mechanisms underlying the prenatal modulation of the adaptation to an environment with unstable resources in a way that optimizes reproductive fitness.


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