Effects of esketamine on depression-like behavior and dendritic spine plasticity in the prefrontal cortex neurons of spared nerve injury-induced depressed mice

The present study utilized the spared nerve injury (SNI) to create a mouse model of depression to investigate the impact of esketamine on depressive-like behaviors, on the expression of PSD-95 and CRMP2 proteins, and on changes in neuronal dendritic spine plasticity in the prefrontal cortex (PFC). Depressive-like behavioral tests were performed 1 h after esketamine treatment, and the PFC tissues were obtained on the fourth day after completing the behavioral tests. Then, dendritic spine density and morphology in the PFC were measured using Golgi staining, and CRMP2 and PSD-95 proteins were obtained from PFC tissue by western blotting. The results of this study showed that esketamine significantly increased the immobility time in the forced swimming test and tail suspension test. In the open field test, esketamine increased the time spent in the open arms, the time spent in the central area, and the total distance covered. It also increased the protein expression levels of CRMP2 and PSD-95 in addition to the total and mature dendritic spine density of the PFC in SNI-depressed mice. Esketamine can significantly improve depression-like behaviors in SNI-depressed mice and promote an increase in dendritic spine density and maturation in the PFC. These effects may be associated with changes in CRMP2 and PSD-95 expression.

Study of mandibular buccal gingival mucosa pain sensitivity / 口腔疾病防治

Objective@# Through a pain study of buccal gingival mucosa sensitivity of the mandible, the corresponding sensitive area of pain was determined, which provided the basis for reducing the pain and discomfort of oral diagnosis and treatment.@*Methods@#400 patients with mandibular tooth extraction in the outpatient department of stomatology were selected. During tooth extraction, articaine epinephrine injection was used for infiltration anesthesia. The injection needle size was 0.3 mm × 21 mm, and the injection site was about 5 mm away from the buccal gingival margin. The pain degree of the patients was recorded. The data were statistically analyzed using the modified International pain classification method.@*Results @#Among the 400 patients who underwent mandible extraction, 75% (300 patients) graded their pain from painless to moderate, and 25% (100 patients) reported moderate to severe and severe pain. Of those in the moderate to severe and severe groups, 50% and 42% reported pain in the central and lateral incisors, respectively, and 38% were in the canine group. When comparing the moderate to severe and the severe groups, 16% and 10% were in the bicuspid group, 16% and 12% and 16% were in the molar group, respectively . There were significant differences in the pain sensitivity of different teeth positions (χ2=54.203, P < 0.001). The proportion of moderate to severe and severe pain in the anterior teeth group was higher than it was in the posterior teeth group (χ2=55.555, P < 0.001). There were significant differences in the pain sensitivity of different ages (χ2=96.501, P=0.000), and there was a positive correlation between pain and age (r=0.465, P < 0.001). The proportion of women with at least a moderate degree of pain was higher than that of men (χ2=12.298, P=0.031). @*Conclusion@# The sensitivity of the buccal gingival mucosa to pain is different in different positions of the mandible. The sensitivity of the anterior gingiva is higher than that of the posterior gingiva. Age is positively correlated with the degree of pain. Further, compared with men, women are more sensitive to pain.