Objective:This study aims to analyze the threshold changes in distortion product otoacoustic emissions（DPOAE） and auditory brainstem response（ABR） in adult Otof-/- mice before and after gene therapy, evaluating its effectiveness and exploring methods for assessing hearing recovery post-treatment. Methods:At the age of 4 weeks, adult Otof-/- mice received an inner ear injection of a therapeutic agent containing intein-mediated recombination of the OTOF gene, delivered via dual AAV vectors through the round window membrane（RWM）. Immunofluorescence staining assessed the proportion of inner ear hair cells with restored otoferlin expression and the number of synapses.Statistical analysis was performed to compare the DPOAE and ABR thresholds before and after the treatment. Results:AAV-PHP. eB demonstrates high transduction efficiency in inner ear hair cells. The therapeutic regimen corrected hearing loss in adult Otof-/- mice without impacting auditory function in wild-type mice. The changes in DPOAE and ABR thresholds after gene therapy are significantly correlated at 16 kHz. Post-treatment,a slight increase in DPOAE was observeds,followed by a recovery trend at 2 months post-treatment. Conclusion:Gene therapy significantly restored hearing in adult Otof-/- mice, though the surgical delivery may cause transient hearing damage. Precise and gentle surgical techniques are essential to maximize gene therapy's efficacy.
Mice ; Animals ; Otoacoustic Emissions, Spontaneous/physiology* ; Hearing/physiology* ; Ear, Inner ; Hearing Loss/therapy* ; Genetic Therapy ; Auditory Threshold/physiology* ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Membrane Proteins

Humans ; Auditory Pathways ; Hearing Loss, Sensorineural ; Cochlear Implantation ; Cochlear Implants ; Hearing Loss, Central ; Auditory Threshold ; Evoked Potentials, Auditory, Brain Stem

Objective: To analyze the surgical efficacy of patients with mixed hearing loss and otosclerosis with different air bone gap (ABG) before surgery, and to provide reference for the prognosis evaluation of otosclerosis surgery. Methods: The clinical data of 108 cases(116 ears) of otosclerosis who had undergone stapes fenestration technique artificial stapes implantation in Xiangya Hospital of Central South University from November 2013 to May 2020 and had mixed hearing loss before surgery were collected, including 71 women(76 ears)and 37 men (40 ears), with an average age of 38.5 years. According to preoperative pure tone audiometry ABG, they were divided into three groups: group S, 15 dB≤ABG<31 dB, a total of 39 ears; group M, 31 dB≤ABG<46 dB, a total of 58 ears; and group L, ABG≥46 dB, 19 ears in total. The hearing outcomes of three groups of patients at 6-12 months after surgery were compared and analyzed using SPSS 24.0 statistical software. Results: A total of 3 patients (group S: 2 cases; group L: 1 case) experienced severe sensorineural hearing loss after surgery and were not included in the statistical analysis. After surgery, the pure tone hearing threshold of patients with otosclerosis in each group was significantly improved compared to before surgery, with an average air conduction threshold improvement of(21.6±13.4) dB. The difference between before and after surgery was statistically significant(t=17.13, P<0.01). The average bone conduction threshold improved by(3.7±7.6) dB, and the difference was statistically significant before and after surgery(t=5.20, P<0.01). The postoperative ABG was(18.3±9.3) dB, which was significantly reduced compared to preoperative(36.2±8.6)dB. Among the three groups of patients, the L group had the highest improvement in air conduction threshold[(29.9±10.8)dB], while the S group had the lowest improvement[(15.7±11.4)dB]. There was no statistically significant difference in post operative pure tone hearing thresholds between the three groups(P>0.05). The postoperative ABG in group S was the smallest[(16.5±9.0)dB], while in group L, the postoperative ABG was the largest[(20.5±10.0)dB]. Compared with group S, group M and group L still had a large residual ABG at 2 000 Hz after surgery. The bone conduction threshold of both S and M groups improved to some extent after surgery compared to before (P<0.01). Conclusions: Surgery can benefit patients with mixed hearing loss and otosclerosis with different preoperative ABG. Patients with small preoperative ABG have better surgical results and ideal ABG closure at all frequencies after surgery. Patients with large preoperative ABG can significantly increase the gas conduction threshold during surgery, but certain frequencies of ABG may still be left behind after surgery. The improvement effect of surgery on bone conduction threshold is not significant. Patients should be informed of treatment methods such as hearing aids based on their actual situation for selection.
Male ; Humans ; Female ; Adult ; Bone Conduction ; Otosclerosis/surgery* ; Hearing Loss, Mixed Conductive-Sensorineural/surgery* ; Stapes Surgery/methods* ; Treatment Outcome ; Auditory Threshold ; Hearing ; Audiometry, Pure-Tone ; Deafness ; Retrospective Studies

The qualitative, quantitative, and localization analysis of hearing loss is one of the important contents of forensic clinical research and identification. Pure-tone audiometry is the "gold standard" for hearing loss assessment, but it is affected by the subjective cooperation of the assessed person. Due to the complexity of the auditory pathway and the diversity of hearing loss, the assessment of hearing loss requires the combination of various subjective and objective audiometric techniques, along with comprehensive evaluation based on the case situation, clinical symptoms, and other examinations to ensure the scientificity, accuracy and reliability of forensic hearing impairment assessment. Objective audiometry includes acoustic impedance, otoacoustic emission, and various auditory evoked potentials. The frequency-specific auditory brainstem response (ABR), 40 Hz auditory event related potential, and auditory steady-state response are commonly used for objective hearing threshold assessment. The combined application of acoustic impedance, otoacoustic emission and ABR can be used to locate hearing loss and determine whether it is located in the middle ear, cochlea, or posterior cochlea. This article reviews the application value of objective audiometry techniques in hearing threshold assessment and hearing loss localization, aiming to provide reference for forensic identification of hearing loss.
Humans ; Reproducibility of Results ; Auditory Threshold/physiology* ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Hearing Loss/diagnosis* ; Audiometry, Pure-Tone/methods* ; Clinical Medicine

OBJECTIVES: This study aimed to investigate whether the microglia in the spinal trigeminal nucleus caudal part (Sp5C) were activated in a rat model of trigeminal neuralgia and to explore whether the activation level of microglia is consistent with maxillofacial pain level. METHODS: Chronic constriction injury of trigeminal nerve (CCI) was induced by partial ligation of infraorbital nerve (IoN) in rats. The behavioral change of rats observed at D1, D5, D10, D15, and D30 days post-surgery and the change of pain threshold were detected with electronic Von Frey filaments served as an evaluation index of maxillofacial pain. Weight change was measured by weighing. Ionized calcium binding adaptor molecule-1 (Iba-1) expression level of Sp5C at each time point was detected, and three microglia morphological categories were analyzed by immunohistochemical staining. RESULTS: The changes of behavioral and pain threshold suggested the maxillofacial pain level first increased and then decreased post-surgery in the IoN-CCI group. Both the expressions of Iba-1 and proportion of ameboid morphology in ipsilateral Sp5C increased from D1 and reached their peaks in D10 and D5, respectively. Then, they recovered nearly to the same level with contralateral Sp5C on D30. This trend was consistent with the maxillofacial change. CONCLUSIONS The model of trigeminal neuralgia in rats constructed by partial ligation of infraorbital nerve can induce the activation of microglia in Sp5C, and the activation level is consistent with maxillofacial pain, which reached its peak at around D10 post-surgery.
Rats ; Animals ; Trigeminal Neuralgia ; Rats, Sprague-Dawley ; Microglia ; Pain Threshold/physiology* ; Pain

OBJECTIVE: To observe the pressure pain threshold (PPT), skin conductance (SC) and blood perfusion (BP) of the sensitized acupoints in patients with knee osteoarthritis (KOA), and explore the mechanism of acupuncture at the sensitized acupoints for treating diseases. METHODS: Eleven healthy subjects and 11 unilateral KOA patients were recruited from July 2020 to March 2021 in this study. The PPT, SC and BP of control acupoints in healthy controls, and non-sensitized and sensitized acupoints in KOA patients were measured and compared between baseline and after manual acupuncture (MA) treatment. RESULTS: Before MA treatment, lower PPT was observed at the sensitized acupoints compared with non-sensitized and control acupoints (P<0.05). After MA treatment, PPT at the sensitized acupoints increased significantly in KOA patients (P<0.05). Before MA treatment, there was no statistical difference in SC and BP among control, non-sensitized and sensitized acupoints (P>0.05). Compared with the control and non-sensitized acupoints, there were significant increases of SC and BP in sensitized acupoints of KOA patients after MA treatment (P<0.05 or P<0.01). CONCLUSION MA at sensitized acupoints could elevate PPT of KOA patients, which may be associated with the increment of SC and BP.
Humans ; Acupuncture Points ; Pain Threshold ; Osteoarthritis, Knee/therapy* ; Acupuncture ; Acupuncture Therapy ; Pain

High level noise can damage cochlear hair cells, auditory nerve and synaptic connections between cochlear hair cells and auditory nerve, resulting in noise-induced hearing loss (NIHL). Recent studies have shown that animal cochleae have circadian rhythm, which makes them different in sensitivity to noise throughout the day. Cochlear circadian rhythm has a certain relationship with brain-derived neurotrophic factor and glucocorticoids, which affects the degree of hearing loss after exposure to noise. In this review, we summarize the research progress of the regulation of cochlear sensitivity to noise by circadian rhythm and prospect the future research direction.
Animals ; Auditory Threshold ; Circadian Rhythm ; Cochlea ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Hair Cells, Auditory ; Hearing Loss, Noise-Induced ; Noise/adverse effects*

Objective: To study the protective effects of metformin on noise-induced hearing loss (NIHL) and its differential protein omics expression profile. Methods: In January 2021, 39 male Wistar rats were randomly divided into control group, noise exposure group and metformin+noise exposure group, with 13 rats in each group. Rats in the noise exposure group and metformin+noise exposure group were continuously exposed to octave noise with sound pressure level of 120 dB (A) and center frequency of 8 kHz for 4 h. Rats in the metformin+noise exposure group were treated with 200 mg/kg/d metformin 3 d before noise exposure for a total of 7 d. Auditory brainstem response (ABR) was used to test the changes of hearing thresholds before noise exposure and 1, 4, 7 d after noise exposure in the right ear of rats in each group. Tandem mass tag (TMT) quantitative proteomics was used to identify and analyze the differentially expressed protein in the inner ear of rats in each group, and it was verified by immunofluorescence staining with frozen sections. Results: The click-ABR thresholds of right ear in the noise exposure group and metformin+noise exposure group were significantly higher than those in the control group 1, 4, 7 d after noise exposure (P<0.05) . The click-ABR threshold of right ear in the metformin+noise exposure group were significantly lower than that in the noise exposure group (P<0.05) . Compared with the noise exposure group, 1035 up-regulated proteins and 1145 down-regulated proteins were differentially expressed in the metformin+noise exposure group. GO enrichment analysis showed that the significantly differentially expressed proteins were mainly involved in binding, molecular function regulation, signal transduction, and other functions. Enrichment analysis of KEGG pathway revealed that the pathways for significant enrichment of differentially expressed proteins included phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt) signaling pathway, focal adhesion, diabetic cardiomyopathy, mitogen, and mitogen-activated protein kinase (MAPK) signaling pathway. Immunofluorescence experiments showed that compared with the noise exposure group, the fluorescence intensity of insulin-like growth factor 1 receptor (IGF1R) in the metformin+noise exposure group was increased, and the fluorescence intensity of eukaryotic translation initiation factor 4E binding protein 1 (eIF4EBP1) was decreased. Conclusion: Noise exposure can lead to an increase in rat hearing threshold, and metformin can improve noise-induced hearing threshold abnormalities through multiple pathways and biological processes.
Animals ; Auditory Threshold/physiology* ; Cochlea ; Ear, Inner ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Hearing Loss, Noise-Induced/prevention & control* ; Male ; Metformin/pharmacology* ; Phosphatidylinositol 3-Kinases/metabolism* ; Rats ; Rats, Wistar

Nicotine is the main addictive component in cigarettes that motivates dependence on tobacco use for smokers and makes it difficult to quit through regulating a variety of neurotransmitter release and receptor activations in the brain. Even though nicotine has an analgesic effect, clinical studies demonstrated that nicotine abstinence reduces pain threshold and increases pain sensitivity in smoking individuals. The demand for opioid analgesics in nicotine abstinent patients undergoing surgery has greatly increased, which results in many side effects, such as nausea, vomiting, and respiratory depression, etc. In addition, these side effects would hinder patients' physical and psychological recovery. Therefore, identifying the neural mechanism of the increase of pain sensitivity induced by nicotine abstinence and deriving a way to cope with the increased demand for postoperative analgesics would have enormous basic and clinical implications. In this review, we first discussed different experimental pain stimuli (e.g., cold, heat, and mechanical pain)-induced pain sensitivity changes after a period of nicotine dependence/abstinence from both animal and human studies. Then, we summarized the effects of the brain neurotransmitter release (e.g., serotonin, norepinephrine, endogenous opioids, dopamine, and γ-aminobutyric acid) and their corresponding receptor activation changes after nicotine abstinence on pain sensitivity. Finally, we discussed the limits in recent studies. We proposed that more attention should be paid to human studies, especially studies among chronic pain patients, and functional magnetic resonance imaging might be a useful tool to reveal the mechanisms of abstinence-induced pain sensitivity changes. Besides, considering the influence of duration of nicotine dependence/abstinence and gender on pain sensitivity, we proposed that the effects of nicotine abstinence and individual differences (e.g., duration of abstinence from smoking, chronic/acute abstinence, and gender) on abstinence-induced pain sensitivity should be fully considered in formulating pain treatment protocols. In summary, this paper could deepen our understanding of nicotine abstinence-induced pain sensitivity changes and its underlying neural mechanism, and could also provide effective scientific theories to guide clinical pain diagnosis and treatment, which has important clinical significance.
Animals ; Humans ; Nicotine/adverse effects* ; Pain ; Pain Threshold ; Smoking Cessation ; Tobacco Use Disorder

Audiology ; Auditory Threshold ; Humans