Publications using TDT

Embryonic development in many species, including case reports in humans, can be temporarily halted before implantation during a process called diapause. Facultative diapause occurs under conditions of maternal metabolic stress such as nursing. While molecular mechanisms of diapause have been studied, a natural inducing factor has yet to be identified. Here, we show that oxytocin induces embryonic diapause in mice. We show that gestational delays were triggered during nursing or optogenetic stimulation of oxytocin neurons simulating nursing patterns. Mouse blastocysts express oxytocin receptors, and oxytocin induced delayed implantation-like dispersion in cultured embryos. Last, oxytocin receptor–knockout embryos transferred into wild-type surrogates had low survival rates during diapause. Our results indicate that oxytocin coordinates timing of embryonic development with uterine progression through pregnancy, providing an evolutionarily conserved mechanism for ensuring successful reproduction.

Steady-state auditory evoked potentials are useful for studying the human auditory system and diagnosing hearing disorders. Identifying the generators of these potentials is essential for interpretation of data and for determining appropriate clinical and research applications. Here we infer putative generators of a steady-state potential measured from an electrode on the eardrum and compare this potential with the traditional envelope following response (EFR) measured from an electrode on the high forehead (N = 18, 10 female). We hypothesized that responses from the eardrum electrode would be consistent with an auditory nerve (AN) compound action potential (CAP) evoked by each cycle of the stimulus envelope, resulting in a potential we call CAPENV. Steady-state potentials were evoked by a 90 dB peSPL, 3000-Hz puretone carrier whose envelope was modulated by a tone sweep with frequencies from 20 to 160 Hz or 80 to 640 Hz. We calculated group delay to infer potential generators. We also compared the empirically measured CAPENV with simulated CAPENV from a humanized model of AN responses. Response latencies and model simulations support the interpretation that CAPENV is generated by the AN rather than hair cell or brainstem generators for all modulation frequencies tested. Conversely, latencies for the traditional EFR were consistent with a shift from cortical to brainstem generators as the modulation frequency increased from 20 to 200 Hz. We propose that CAPENV may be a fruitful tool for assessing AN function in humans with suspected AN fiber loss and/or temporal coding disorders.

Mesolimbic dopamine encoding of non-contingent rewards and reward-predictive cues has been well established. Considerable debate remains over how mesolimbic dopamine responds to aversion and in the context of aversive conditioning. Inconsistencies may arise from the use of aversive stimuli that are transduced along different neural paths relative to reward or the conflation of responses to avoidance and aversion. Here, we made intraoral infusions of sucrose and measured how dopamine and behavioral responses varied to the changing valence of sucrose. Pairing intraoral sucrose with malaise via injection of lithium chloride (LiCl) caused the development of a conditioned taste aversion (CTA), which rendered the typically rewarding taste of sucrose aversive upon subsequent re-exposure. Following CTA formation, intraoral sucrose suppressed the activity of ventral tegmental area dopamine neurons (VTA DA ) and nucleus accumbens (NAc) dopamine release. This pattern of dopamine signaling after CTA is similar to intraoral infusions of innately aversive quinine and contrasts with responses to sucrose when it was novel or not paired with LiCl. Dopamine responses were negatively correlated with behavioral reactivity to intraoral sucrose and predicted home cage sucrose preference. Further, dopamine responses scaled with the strength of the CTA, which was increased by repeated LiCl pairings and weakened through extinction. Thus, the findings demonstrate differential dopamine encoding of the same taste stimulus according to its valence, which is aligned to distinct behavioral responses.

Cisplatin-induced hearing loss is a common and irreversible side effect affecting a significant proportion of cancer patients. While various strategies to mitigate this toxicity have been explored, there remains a critical need for effective treatments. A major challenge in developing new therapies is the lack of reliable animal models that accurately replicate the clinical use of cisplatin in humans, which typically involves multiple cycles of low-dose administration. Traditional models using high doses of cisplatin have resulted in high mortality and variable hearing loss, complicating the assessment of potential treatments. To address this, a multi-cycle model using lower cisplatin doses in mice was developed, providing hearing loss without mortality. However, variability in outcomes across different research groups persisted. In the present study, we optimize the multi-cycle model of cisplatin-induced ototoxicity by using clinical-grade cisplatin rather than laboratory-grade formulations. The use of clinical cisplatin ensures greater consistency, reliability, and relevance to human treatment protocols, as it adheres to the rigorous quality standards required for patient use. This new administration protocol will minimize variability across research laboratories and more accurately mimic the dosing regimens typically administered to cancer patients. Additionally, we have enhanced a zebrafish model for high-throughput screening of potential therapeutics, further improving the consistency of results. These improvements to the animal models are critical for accelerating the discovery and testing of therapies to prevent cisplatin-induced hearing loss, supporting the development of effective treatments for cancer patients undergoing cisplatin chemotherapy.

Background Sensorineural hearing loss (SNHL) is among the most common sensory disorders, significantly affecting various aspects of the quality of life of an individual. Oxidative stress and inflammation have been involved in the progression of various forms of SNHL and are potential pathological mechanisms of the disorder. However, the synergistic effects of oxidative stress and inflammation on cochlear function is not completely understood. Methods We explored the effects of oxidative stress and inflammation on cochlear damage and hearing impairment in male C57BL/6 mice aged 6 to 7 weeks. These in the experimental group were administered with oxidant Menadione bisulfite (MD) and the endotoxin lipopolysaccharide (LPS) via intraperitoneal route to induce oxidative stress and inflammation, whereas the control group received saline. The degree of cochlear damage was analyzed based on auditory thresholds, hair cells (HCs) loss, and the expression of protein markers related to oxidative stress, inflammation, necroptosis, and ferroptosis. Results After six days of alternating MD and LPS injections, there was a notable elevation in hearing thresholds, which was associated with a substantial loss of HCs and spiral ganglion cells. Immunofluorescence analysis demonstrated the activation of oxidative stress, inflammation, necroptosis, and ferroptosis signaling pathways after treatment. Notably, the administration of either MD or LPS alone did not result in significant changes. Conclusion These findings indicate that the interaction between oxidative stress and inflammation may exacerbate cochlear damage and contribute to hearing loss, potentially through the activation of necroptosis and ferroptosis pathways. Our results may identify potential therapeutic targets for the management of SNHL.

Background: Hearing loss, a major public health issue, affects 1.33 per 1,000 live births worldwide. Genetic factors contribute to over half of congenital cases, with X-linked inheritance accounting for 1-5%. POU3F4 mutations are associated with approximately 50% of X-linked non-syndrome hearing loss cases. POU3F4 plays a critical role in cochlear development by regulating otic mesenchyme cell differentiation. The study investigates the impact of a novel POU3F4 p.E294G mutation on cochlear structure and function using cellular and animal model. Methods: The study utilized immortalized lymphoblastoid cell lines, POU3F4 overexpressed HEK293 cells and generated Pou3f4 knock-in (Pou3f4KI) mice via CRISPR/Cas9 to introduce the p.E294G mutation. Alterations in expression and subcellular localization of POU3F4 were detected at the cellular level. Auditory function was assessed using auditory brainstem response testing. Cochlear structure was analyzed through histology, immunohistochemistry, scanning electron microscopy, and transmission electron microscopy. RNA sequencing, qPCR and Western blot were conducted to evaluate gene expression and mitochondrial function. Results: The transcription of POU3F4 was abnormal and the expression was normal in lymphoblastoid cell lines. Abnormal nuclear localization of POU3F4 p.E294G was found in overexpressed HEK293 cells. Pou3f4KI mice exhibited cochlear malformations, including modiolus hypoplasia and reduced stria vascularis cell populations. Auditory testing revealed progressive hearing loss. Pou3f4 affect mitochondrial protein expression by affecting the expression of TFAM. Mitochondrial dysfunction was evident, with reduced oxidative phosphorylation (OXPHOS) complex assembly and activity, decreased ATP levels. The level of reactive oxygen species, mitochondrial fission and apoptosis in cochlea were elevated. Conclusions: The POU3F4 p.E294G resulted in abnormal nuclear localization. Pou3f4 mutant disrupts cochlear development and function, impairs mitochondrial integrity, induces oxidative stress, and promotes apoptosis, leading to progressive hearing loss. The findings enhance the understanding of POU3F4-related hearing loss mechanisms and highlight the importance of early genetic screening and audiological monitoring.

Certain medications, including cisplatin and neomycin, often cause both hearing loss and renal dysfunction. This study aims to uncover the common mechanisms behind drug‐induced ototoxicity and nephrotoxicity to aid early diagnosis and treatment. Metabolomic analyses reveal simultaneous disruptions in endogenous metabolic networks in the kidney, inner ear, and serum after administrating cisplatin or neomycin. Notably, a marked elevation in uric acid (UA), a recognized indicator of renal tubular injury, is identified. Supplementing UA and inhibiting its renal excretion worsen hearing loss and hair cell damage. Single‐cell nucleus sequencing and immunohistochemistry reveal major changes in xanthine oxidase and ABCG2 , crucial for UA metabolism, primarily in cochlear stria vascularis cells rather than hair cells. Cisplatin triggers a significant release of UA from stria vascularis cells, reaching concentrations sufficient to induce autophagy‐dependent ferroptosis in hair cells. In a coculture system, targeted interventions against these two proteins in stria vascularis cells, through either pharmacological inhibition or genetic manipulation, markedly decrease the elevated UA release and the subsequent ferroptosis of hair cells. These findings suggest a metabolic connection between the inner ear and the kidney, highlighting the therapeutic potential of modulating UA to mitigate drug‐induced nephrotoxicity and ototoxicity.

Epilepsy is a multifaceted neurological disorder characterized by recurrent seizures and associated with molecular and immune alterations in key brain regions. The GASH/Sal (Genetic Audiogenic Seizure Hamster, Salamanca), a genetic model for audiogenic epilepsy, provides a powerful tool to study seizure mechanisms and resistance in predisposed individuals. This study investigates the proteomic and immune responses triggered by audiogenic kindling in the inferior colliculus, comparing non-responder animals exhibiting reduced seizure severity following repeated stimulation versus GASH/Sal naïve hamsters. To assess auditory pathway functionality, Auditory Brainstem Responses (ABRs) were recorded, revealing reduced neuronal activity in the auditory nerve of non-responders, while central auditory processing remained unaffected. Cytokine profiling demonstrated increased levels of proinflammatory markers, including IL-1 alpha (Interleukin-1 alpha), IL-10 (Interleukin-10), and TGF-beta (Transforming Growth Factor beta), alongside decreased IGF-1 (Insulin-like Growth Factor 1) levels, highlighting systemic inflammation and its interplay with neuroprotection. Building on these findings, a proteomic analysis identified 159 differentially expressed proteins (DEPs). Additionally, bioinformatic approaches, including Gene Set Enrichment Analysis (GSEA) and Weighted Gene Co-expression Network Analysis (WGCNA), revealed disrupted pathways related to metabolic and inflammatory epileptic processes and a module potentially linked to a rise in the threshold of seizures, respectively. Differentially expressed genes, identified through bioinformatic and statistical analyses, were validated by RT-qPCR. This confirmed the upregulation of six genes (Gpc1—Glypican-1; Sdc3—Syndecan-3; Vgf—Nerve Growth Factor Inducible; Cpne5—Copine 5; Agap2—Arf-GAP with GTPase domain, ANK repeat, and PH domain-containing protein 2; and Dpp8—Dipeptidyl Peptidase 8) and the downregulation of two (Ralb—RAS-like proto-oncogene B—and S100b—S100 calcium-binding protein B), aligning with reduced seizure severity. This study may uncover key proteomic and immune mechanisms underlying seizure susceptibility, providing possible novel therapeutic targets for refractory epilepsy.

FKBP5 is a 51-Da FK506-binding protein and member of the immunophilin family involved in controlling the signaling of glucocorticoid receptor from the cytosol to nucleus. Fkbp5 has previously been shown to be expressed in murine cochlear tissue, including the organ of Corti (i.e., the sensory epithelium of the cochlea). Fkbp5-/- mice as used in this study show hearing loss in the low-frequency (8-kHz) range and click-evoked auditory brainstem response (ABR) threshold compared to wild-type mice. Both Fkbp5-/- and wild-type mice showed hearing loss at all frequencies and click-ABR thresholds at 24 h and 14 days following acoustic overexposure (AO). Tissues of the organ of Corti were subjected to RNA sequencing and KEGG pathway analysis. In Fkbp5-/- mice before AO, the mitogen-activated protein kinase (MAPK) signaling pathway was dysregulated compared to wild-type mice. In wild-type mice at 12 h following AO, the most significantly modulated KEGG pathway was the TNF signaling pathway and major MAPK molecules p38 and Jun were involved in the TNF signaling pathway. In Fkbp5-/- mice at 12 h following AO, the MAPK signaling pathway was dysregulated compared to wild-type mice following AO. In conclusion, Fkbp5 interacts with MAPK signaling in the organ of Corti in mice cochleae.

Voluntary, flexible stopping of speech output is an essential aspect of speech motor control, especially during natural conversations. The cognitive and neural mechanisms of speech inhibition are not well understood. Here we have recorded direct high-density cortical activity while participants engaged in continuous speech production and were visually cued to stop speaking. Neural recordings revealed distinct activity in the premotor frontal cortex correlated with stopping speech. This activity was found in largely separate cortical sites from regions encoding vocal tract articulatory movements. Moreover, this activity primarily occurred with abrupt stopping in the middle of an utterance, rather than naturally completing a phrase. Electrocortical stimulation at many premotor sites with inhibitory stop activity caused involuntary speech arrest, which contradicts previous clinical interpretations of this effect as evidence for critical centres of speech production. Together, these results suggest a previously unknown premotor cortical network that supports the inhibitory control of speech, providing implications for understanding both natural and altered speech production.

Background: Xeroderma pigmentosum (XP) is caused by impaired DNA repair of UV-induced dipyrimidine-photoproducts. XP cells also show impaired repair/removal of ROS or oxidative DNA lesions caused by UV or 4-nitroquinolline 1-oxide (4NQO). Gene profiling indicated that inflammatory response-related genes are significantly upregulated after UV exposure in XP-A model mice. Objective: Since XP cells are in the state of oxidative stress and inflammation, we aimed to search for therapeutic agents from anti-oxidants/anti-inflammatory drugs, that potentially improve XP symptoms. Methods: Several antioxidants were examined for reducing 4NQO-induced oxidative cytotoxicity or UV-induced oxidative DNA damage in XP-A cells. Among them, we focused on melatonin and evaluated its improving effect for Xpa-deficient MEF on UV-induced cytotoxicity and ROS production, and for Xpa-deficient mice on UV-induced skin tumorigenesis and auditory brainstem responses as one of the neurological symptoms. Results: Melatonin and nicotinamide attenuated 4NQO-induced oxidative cytotoxicity. UV-induced intracellular ROS production and cytotoxicity were improved by melatonin for Xpa-deficient MEF. Finally, the administration of melatonin mitigated UV-induced skin inflammation and tumorigenesis and suppressed hearing deterioration in Xpa-deficient mice. Conclusion: Our results show that melatonin could alleviate XP symptoms through its anti-inflammatory and antioxidant properties.

Humans and mice with mutations in genes encoding CIB2 and whirlin (WHRN) are deaf. We previously reported that CIB2 binds to WHRN and is essential for stereocilia staircase architecture of cochlear hair cells. Here, we refine the interaction domains of both proteins and show that these proteins play unique roles in stereocilia bundle formation and organization. We found that the EF2 domain of CIB2 binds to the HHD2 region of WHRN. AlphaFold2 multimer independently identified the same interacting regions and gave a thorough structural model. Next, we investigated genetic interaction between murine Cib2 and Whrn. Hearing in mice double heterozygous for functionally null alleles (Cib2KO/+;Whrnwi/+) was similar to that in age-matched wild-type mice, indicating that partial deficiency for both Cib2 and Whrn does not impair hearing. Double homozygous mutant mice (Cib2KO/KO;Whrnwi/wi) were deaf, and their cochlear stereocilia exhibited a predominant phenotype seen in single Whrnwi/wi mutants. Overexpression of WHRN in Cib2KO/KO mice did not rescue the stereocilia morphology. These data suggest that CIB2 is multifunctional, with key independent functions in the development and/or maintenance of the stereocilia staircase pattern in auditory hair cells.

Here, we present a protocol to decode Mandarin sentences from invasive neural recordings using a brain-to-text framework. We describe steps for preparing materials, including designing the sentence corpus and setting up electrocorticography (ECoG) recording systems. We then detail procedures for decoding, such as data preprocessing, selection of speech-responsive electrodes, speech detection, syllable and tone decoding, and language modeling. We also outline performance evaluation metrics. For complete details on the use and execution of this protocol, please refer to Zhang et al.1.

We used several post hoc pooling models to investigate the ability of primate auditory cortex to leverage population coding in the detection of amplitude-modulated sounds. When cells are indiscriminately pooled, primary auditory cortex (A1) detects amplitude-modulated sounds better than middle-lateral belt (ML). When cells that decrease firing rate with increasing modulation depth are excluded, or used in a push-pull opponent fashion, detection is similar in the two areas, and macaque behavior can be approximated using reasonably sized pools.

Objective: This study aims to investigate how reproductive experience (RE) alters thermal preference and thermoregulation in female mice, with a focus on estrogen receptor alpha (ERα)-expressing neurons in the preoptic area (POA). Methods: Thermal preference and body temperature were measured in female mice with and without RE, and virgin female mice with selective deletion of ERα from the POA (ERαPOA-KO). The number and activity of ERα-expressing POA neurons (ERαPOA) were assessed using immunohistochemistry and in vitro electrophysiology in response to temperature changes and ERα agonist. Results: We showed that female mice prefer a cooler environment starting from late pregnancy and persisting long term postpartum. Female mice with RE (>4 weeks post-weaning) displayed lower body temperature and a lower thermal preferred temperature, and lost preference for warm environments (30 °C) but preserved avoidance of cold environments (15 °C). This was associated with a significant decrease in the number of ERαPOA neurons. Importantly, virgin female ERαPOA-KO mice displayed lower thermal preferred temperature and impaired warm preference, mimicking RE mice. We further found that distinct ERαPOA subpopulations can be regulated by temperature changes with or without presynaptic blockers, and by ERα agonist. More importantly, RE decreased the number of warm-activated ERαPOA neurons and reduced the excitatory effects of warmth and estrogen-ERα signaling, while cold-activated ERαPOA neurons were slightly enhanced in female mice with RE. Conclusion: Our results support that the thermosensing ability and estrogenic effects in ERαPOA neurons are regulated by reproductive experience, altering thermal preference.

It is crucial to manage hearing loss and its associated public health impacts. In this study, we aimed to understand the role of Sema3f in the development and maintenance of the auditory system. Inner ear-specific Sema3f knockout mice exhibited hearing loss at 8 weeks with an elevated threshold for auditory brainstem response and an absent threshold for distortion product optoacoustic emission tests. Additionally, an increased number of outer hair cells and abnormal patterns of spiral ganglion neuron projections in the outer hair cell regions were observed. Through the analyses of sequencing data from 558 families with hearing loss, we identified biallelic variants of SEMA3F, which encodes semaphorin-3F, in one of the families. In the family, the proband showed profound progressive nonsyndromic hearing loss with congenital onset. In vitro analysis revealed that the identified missense variants decreased the furin-mediated processing of SEMA3F and abolished the cellular abilities of SEMA3F, which collapsed the filamentous actin cytoskeleton in human umbilical vein-derived endothelial cells. Our data suggest that SEMA3F is essential for normal hearing and is associated with nonsyndromic hearing loss in humans.

Neural dynamics are thought to reflect computations that relay and transform information in the brain. Previous studies have identified the neural population dynamics in many individual brain regions as a trajectory geometry, preserving a common computational motif. However, whether these populations share particular geometric patterns across brain-wide neural populations remains unclear. Here, by mapping neural dynamics widely across temporal/frontal/limbic regions in the cortical and subcortical structures of monkeys, we show that 10 neural populations, including 2,500 neurons, propagate visual item information in a stochastic manner. We found that visual inputs predominantly evoked rotational dynamics in the higher-order visual area, TE, and its downstream striatum tail, while curvy/straight dynamics appeared frequently downstream in the orbitofrontal/hippocampal network. These geometric changes were not deterministic but rather stochastic according to their respective emergence rates. Our meta-analysis results indicate that visual information propagates as a heterogeneous mixture of stochastic neural population signals in the brain.

Objective: High altitude hypobaric hypoxia can induce hearing impairment and hearing acclimatization, but few studies have been performed to decipher the potential transition between the two states. To decipher transition-related circular RNAs (circRNAs)-microRNAs (miRNAs)-messenger RNA (mRNAs) regulatory network. Methods: Wistar rats were airlifted from plain to high altitude and maintained for 30 days and 60 days. Hearing acclimatization was determined using the Auditory Brainstem Response (ABR) test. Cochlea tissues were isolated, and high-throughput circRNA analysis and mRNAs-sequencing were performed. Differentially Expressed circRNAs (DEcircRNAs) and Differentially Expressed mRNAs (DEmRNAs) were obtained, and circRNA-miRNA and miRNA-mRNA regulation were predicted. A circRNA-miRNA-mRNA competing endogenous RNA (ceRNA) network was also constructed. The DEmRNAs in this network were functionally annotated using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses based on Metascape. Results: The ABR assay indicated that hearing impairment happened on day 30 and hearing acclimatization occurred on day 60. Hearing impairment-related circRNAs (64 upregulated and 147 downregulated) and genes (572 upregulated and 757 downregulated) were identified. Hearing acclimatization-related circRNAs (79 upregulated and 142 downregulated) and genes (690 upregulated and 751 downregulated) were also identified. Hearing impairment and hearing acclimatization ceRNA networks were also constructed after integrating the predicted miRNA regulation analyses. Anterograde trans-synaptic signaling (GO:0098916) and negative regulation of cellular response to growth factor stimulus (GO:0090288) were regulated by hearing impairment ceRNA networks, and embryonic organ development (GO:0048568) was regulated by hearing acclimatization ceRNA networks. Conclusion: Hearing impairment- and hearing acclimatization-associated circRNAs and ceRNA networks were identified, which contribute new knowledge to our understanding of acclimatization transition.

The superior para-olivary nucleus (SPN or SPON) is a prominent nucleus in the superior olivary complex of the auditory brainstem. The cellular composition of the nucleus reportedly differs between species, but a prominent recurring feature is the unusual characteristic to not respond during a sound but at its offset. Blocking glycine has shown that sound-induced inhibition is the mechanism, but the time course of the responsible synaptic events has not been directly measured in vivo. We obtained intracellular recordings in the Mongolian gerbil (meriones unguiculatus) with patch electrodes containing biocytin, and retrieved 12 labeled neurons with large dendritic trees within and around the SPN region. We found that these neurons could be categorized into three classes that show consistency along multiple dimensions like ultrastructure, spontaneous activity, and responses to current injection and a variety of ipsi- and contralateral sounds. Fast cells fire at onset of depolarizing current, generate short-latency rebound spikes to sound or hyperpolarizing current, and show dense synaptic coverage. Slow cells show sparse synaptic coverage, sustained responses to depolarization, and inhibition with a slow time course to hyperpolarizing current or sound. Uninhibited cells form a third class which profoundly differ in their responses to sound, lacking rebound spiking. We propose that fast cells project to the inferior colliculus, and slow cells to the cochlear nucleus.

Although recent work has made headway in understanding the neural temporospatial dynamics of conscious perception, much of that work has focused on visual paradigms. To determine whether there are shared mechanisms for perceptual consciousness across sensory modalities, here we test within the auditory domain. Participants completed an auditory threshold task while undergoing intracranial electroencephalography. Recordings from >2,800 grey matter electrodes were analyzed for broadband gamma power (a range which reflects local neural activity). For perceived trials, we find nearly simultaneous activity in early auditory regions, the right caudal middle frontal gyrus, and the non-auditory thalamus; followed by a wave of activity that sweeps through auditory association regions into parietal and frontal cortices. For not perceived trials, significant activity is restricted to early auditory regions. These findings show the cortical and subcortical networks involved in auditory perception are similar to those observed with vision, suggesting shared mechanisms for conscious perception.