Objective To investigate the spatiotemporal expression pattern of metabotropic glutamate receptor 4(mGluR4)in the mouse cochlear basilar membrane and its dynamic changes during postnatal development until hair cell synaptic maturation.Methods Ten healthy 3-month-old C57BL/6L wild-type mice(5 males,5 females,25～35 g)were bred to obtain offspring.Cochlear samples from postnatal days 1～30(P1～P30)were analyzed.Frequency-specific auditory brainstem response(ABR)thresholds were measured at 45.2,32.0,22.6,16.0,11.3,8.0,5.6,and 4.0 kHz in P12,P14,P16,P21,and P30 mice.Immunofluorescence assay combined with confocal laser scanning microscopy was used to scan cochlear whole-mount preparations.Spatiotemporal co-localization profiling of mGluR4 and synaptic markers Ctbp2 and Snap25 was observed,and quantitative comparisons of fluorescent puncta density were performed.Results ABR testing revealed undifferentiated waveforms in all P12 mice,while 70%of P14 mice exhibited well-defined Wave I.In P14,P16,P21 and P30,mice undergoing ABR testing,50%failed to exhibit ABR waveforms when stimulated by 45.2 kHz tones,and 87.5%showed no response to 32.0 kHz stimuli.Auditory response thresholds for other frequencies progressively decreased with increasing postnatal age.Immunolocalization demonstrated stronger mGluR4 expression in inner hair cells(IHCs)versus outer hair cells(OHCs).Distinct mGluR4 puncta were observed at IHC presynaptic active zones(co-localized with Snap25)as early as P11,but showed minimal overlap with CtBP2-labeled ribbons.Quantitative analysis revealed significantly higher mGluR4 puncta density at P30 compared to P14 synapses(P<0.05).Conclusion Postnatal upregulation of mGluR4 at IHC synaptic regions correlates with functional maturation.These findings suggest mGluR4 may modulate vesicular exocytosis regulation and exert pharmacological inhibition on glutamate release,potentially influencing synaptic plasticity during auditory pathway refinement.

0.05). Secondary caries were 6.85% and 9.20% in the group of ART, 6.35% and 8.62% in drill +glass ionomer restoration, 16.9% and 21.50% in amalgam restorations, respectively( P

Objective: To evaluate the feasibility and safety of postoperative patient-controlled epidural analgesia (PCEA)in children. Methods: Forty postoperative pediatric patients(5-11 years old)were divided into two groups. A and B. Both wereinstituted with postoperative PCEA with LCP model (loading dose 2.05 + 0.13ml), continuos infusion rate 0.82 + 0.15mi/h, PCA dose 0.81 + 0.16ml)by Graseby-9300 PCA pump. The PCEA solution of group A was 0.075% bupivacaine plus0.0012 % buprenorphine, that of group B was same while 0. 005% droperidol was added as an adjuvant. Results:The volumeof PCEA sdution consumption in group B was significantly less than that in group A on the first and second postoperative day (P< 0.01-0.05). Good analgesic efficiency with little side effects was obtained, as evaluated by the VASF emasay or D/D score and complications in two groups, but the analgesic effect of group B was better than that of group A. Conclusion: Thepediatric PCEA with low concentration of bupivaeaine plus buprenorphine is feasible and safe. Droperidol may enhance theanalgesic effects of PCEA.

Objective:To evaluate the safety of patient controlled epidural analgesia (PCEA)for elderly patient. Method: Forty two adult patients after operation were divided into control group(44.4?7.8a)and old group(70.9?5.la) according to their ages. All patients reeeived epidural 0.125% bupivacaine and 0.01% morphine mixture for PCEA. BP,HR, RR and SpO_2 were monitored for the first 24 hours following PCEA. Result: The dosage of the mixture was 33.3?6.8ml in control group and 31.6?8.7ml in old group. BP,HR didn't alter markedly in both groups throughout the whole period. RR and SpO_2 remined normal levels. Conclusion: With adequate dosage PCEA can be used safely for elderly postoperative analgesia