Publications by authors named "Galazyuk A"

Metabotropic glutamate receptors (mGluRs) are widely expressed throughout the central nervous system. They are linked to G-protein coupled receptors and are known to modulate synaptic transmission. The data regarding their expression in auditory structures are not systematic and mainly originate from physiological studies where expression was used to support physiological findings.

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Article Synopsis
  • Bats are increasingly recognized as valuable models for aging research due to their long lifespan, living over 20 to 40 years in the wild or captivity.
  • Their unique biological traits, such as resistance to viral infections and efficient DNA repair mechanisms, offer insights that could enhance healthy aging in humans.
  • The review discusses eight specific areas where bat research can inform our understanding of aging, including genetics, immunity, neurobiology, and even aspects related to menopause, making bats potentially more relevant to human aging studies than traditional lab animals like rodents.
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Homeostatic plasticity, the ability of neurons to maintain their averaged activity constant around a set point value, is thought to account for the central hyperactivity after hearing loss. Here, we investigated the putative role of GABAergic neurotransmission in this mechanism after a noise-induced hearing loss larger than 50 dB in high frequencies in guinea pigs. The effect of GABAergic inhibition is linked to the normal functioning of K + -Cl- co-transporter isoform 2 (KCC2) which maintains a low intracellular concentration of chloride.

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Frugivory evolved multiple times in mammals, including bats. However, the cellular and molecular components driving it remain largely unknown. Here, we use integrative single-cell sequencing (scRNA-seq and scATAC-seq) on insectivorous (Eptesicus fuscus; big brown bat) and frugivorous (Artibeus jamaicensis; Jamaican fruit bat) bat kidneys and pancreases and identify key cell population, gene expression and regulatory differences associated with the Jamaican fruit bat that also relate to human disease, particularly diabetes.

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As bones age in most mammals, they typically become more fragile. This state of bone fragility is often associated with more homogenous collagen fiber orientations (CFO). Unlike most mammals, bats maintain mechanically competent bone throughout their lifespans, but little is known of positional and age-related changes in CFO within wing bones.

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Homeostatic plasticity, the ability of neurons to maintain their averaged activity constant around a set point value, is thought to account for the central hyperactivity after hearing loss. Here, we investigated the putative role of GABAergic neurotransmission in this mechanism after a noise-induced hearing loss larger than 50 dB in high frequencies in guinea pigs. The effect of GABAergic inhibition is linked to the normal functioning of K+-Cl- co-transporter isoform 2 (KCC2) which maintains a low intracellular concentration of chloride.

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Introduction: Neuronal hyperactivity has been associated with many brain diseases. In the auditory system, hyperactivity has been linked to hyperacusis and tinnitus. Previous research demonstrated the development of hyperactivity in inferior colliculus (IC) neurons after sound overexposure, but the underlying mechanism of this hyperactivity remains unclear.

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The amygdala, a brain center of emotional expression, contributes to appropriate behavior responses during acoustic communication. In support of that role, the basolateral amygdala (BLA) analyzes the meaning of vocalizations through the integration of multiple acoustic inputs with information from other senses and an animal's internal state. The mechanisms underlying this integration are poorly understood.

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Frugivory evolved multiple times in mammals, including bats. However, the cellular and molecular components driving it remain largely unknown. Here, we used integrative single-cell sequencing on insectivorous and frugivorous bat kidneys and pancreases and identified key cell population, gene expression and regulatory element differences associated with frugivorous adaptation that also relate to human disease, particularly diabetes.

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The startle reflex (SR), a robust, motor response elicited by an intense auditory, visual, or somatosensory stimulus has been widely used as a tool to assess psychophysiology in humans and animals for almost a century in diverse fields such as schizophrenia, bipolar disorder, hearing loss, and tinnitus. Previously, SR waveforms have been ignored, or assessed with basic statistical techniques and/or simple template matching paradigms. This has led to considerable variability in SR studies from different laboratories, and species.

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Neural hyperactivity induced by sound exposure often correlates with the development of hyperacusis and/or tinnitus. In laboratory animals, hyperactivity is typically induced by unilateral sound exposure to preserve one ear for further testing of hearing performance. Most ascending fibers in the auditory system cross into the superior olivary complex and then ascend contralaterally.

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Exceptionally long-lived species, including many bats, rarely show overt signs of aging, making it difficult to determine why species differ in lifespan. Here, we use DNA methylation (DNAm) profiles from 712 known-age bats, representing 26 species, to identify epigenetic changes associated with age and longevity. We demonstrate that DNAm accurately predicts chronological age.

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Little is known about the functions of Group II metabotropic glutamate receptors (mGluRs2/3) in the inferior colliculus (IC), a midbrain structure that is a major integration region of the central auditory system. We investigated how these receptors modulate sound-evoked and spontaneous firing in the mouse IC We first performed immunostaining and tested hearing thresholds to validate vesicular GABA transporter (VGAT)-ChR2 transgenic mice on a mixed CBA/CaJ x C57BL/6J genetic background. Transgenic animals allowed for optogenetic cell-type identification.

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Animal models have significantly contributed to understanding the pathophysiology of chronic subjective tinnitus. They are useful because they control etiology, which in humans is heterogeneous; employ random group assignment; and often use methods not permissible in human studies. Animal models can be broadly categorized as either operant or reflexive, based on methodology.

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The development of knockin mice with Cre recombinase expressed under the control of the promoter for choline acetyltransferase (ChAT) has allowed experimental manipulation of cholinergic circuits. However, currently available ChAT mouse lines are on the C57BL/6J strain background, which shows early onset age-related hearing loss attributed to the Cdh23 mutation (a.k.

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Neurons in various sensory systems show some level of spontaneous firing in the absence of sensory stimuli. In the auditory system spontaneous firing has been shown at all levels of the auditory pathway from spiral ganglion neurons in the cochlea to neurons of the auditory cortex. This internal "noise" is normal for the system and it does not interfere with our ability to perceive silence or analyze sound.

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The acoustic startle reflex (ASR) is subject to substantial variability. This inherent variability consequently shapes the conclusions drawn from gap-induced prepulse inhibition of the acoustic startle reflex (GPIAS) assessments. Recent studies have cast doubt as to the efficacy of this methodology as it pertains to tinnitus assessment, partially, due to variability in and between data sets.

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Tinnitus is the perception of a sound that has no external source. Sound stimuli can suppress spontaneous firing in auditory neurons long after stimulus offset. It is unknown how changes in sound stimulus parameters affect this forward suppression.

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The etiology of tinnitus is known to be diverse in the human population. An appropriate animal model of tinnitus should incorporate this pathological diversity. Previous studies evaluating the effect of acoustic over exposure (AOE) have found that animals typically display increased spontaneous firing rates and bursting activity of auditory neurons, which often has been linked to behavioral evidence of tinnitus.

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The high prevalence of noise-induced and age-related hearing loss in the general population has warranted the use of animal models to study the etiology of these pathologies. Quick and accurate auditory threshold determination is a prerequisite for experimental manipulations targeting hearing loss in animal models. The standard auditory brainstem response (ABR) measurement is fairly quick and translational across species, but is limited by the need for anesthesia and a lack of perceptual assessment.

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Background: The acoustic startle reflex (ASR) is a rapid, involuntary movement to sound, found in many species. The ASR can be modulated by external stimuli and internal state, making it a useful tool in many disciplines. ASR data collection and interpretation varies greatly across laboratories making comparisons a challenge.

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The progress in the field of tinnitus largely depends on the development of a reliable tinnitus animal model. Recently, a new method based on the acoustic startle reflex modification was introduced for tinnitus screening in laboratory animals. This method was enthusiastically adopted and now widely used by many scientists in the field due to its seeming simplicity and a number of advantages over the other methods of tinnitus assessment.

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