Day-old chick is unique animal model in brain development and behavior study. The intermediate medial mesopallium (IMM), a region of the chick forebrain, is intimately involved in the early learning processes, which offers the ideal opportunity to study the neural changes that underlie behavioral plasticity. In this paper, the intracellular recordings were conducted from IMM neurons in chick forebrain slices, in which electrophysiological properties, synaptic responses and long-term potentiation (LTP) were observed. Coronal sections of left forebrains (500 mum thick), containing IMM, were prepared from domestic chicks, aged 2-10 days. In 69 IMM neurons, the resting membrane potential was measured to be (-59.4+/-5.3) mV, slope membrane resistance (70.8+/-27.2) MΩ, and time constant (10.2+/-4.3) ms. The amplitude, threshold, overshoot, half-width, max rise slope and max decay slope of action potential evoked by intracellular current injection were (85.2+/-9.4) mV, (-38.7+/-7.6) mV, (25.6+/-8.9) mV, (2.1+/-0.5) ms, (150.5+/-41.2) mV/ms and (-64.3+/-14.0) mV/ms, respectively. Spike-firing frequency was increased with depolarizing current intensity in 32 of 69 tested cells [linear regression slope was (21.5+/-10.9) Hz/nA, P<0.05 in all cells]. The depolarizing synaptic responses (i.e. EPSPs), with stimulus intensity- and membrane potential-dependent properties, were elicited by dorsal (n=25) or ventral (n=62) focal electrical stimuli at 0.1 Hz in all tested IMM neurons and could be nullified reversibly by perfusion with 100 mumol/L AP5 (NMDA receptor antagonist) and 3 mumol/L DNQX (non-NMDA receptor antagonist), but enlarged by 6 mumol/L bicuculline (GABA(A) receptor antagonist). The EPSPs evoked by ventral stimulation were persistently increased after tetanic stimulation (5 Hz, 300 pulses/train, 2 trains, train interval 10 min) in 6 of 12 tested IMM neurons. The amplitude of EPSPs was potentiated to more than 120% of control level (when analyzed at 45 min of enhancement, P<0.05, n=5), which lasted at least 30 min and then could be referred to as LTP. Moreover, area under curve, duration and max rise slope of EPSPs were also enhanced (P<0.05), while no significant changes were observed in the electrophysiological parameters of IMM neurons following induction of LTP (P>0.05). These results suggest that the intracellular recording techniques in the chick brain slices can be used to perform multi-parameter analysis of synaptic responses and their LTP.
Animals ; Brain ; physiology ; Chickens ; In Vitro Techniques ; Long-Term Potentiation ; Membrane Potentials ; Receptors, N-Methyl-D-Aspartate ; antagonists & inhibitors

OBJECTIVE: To study the physical growth characteristics of birthweight discordant twins(BDT)under 4 years old. METHODS: The physical growth characteristics of BDT under 4 years old born from September 2010 to December 2017 in child health care system of Children's Hospital of Chongqing Medical University were analyzed retrospectively. R 3.5.3 was used to clean up the database,analyze the distribution of different degree of birthweight discordance,and draw the fitting curves. More than 20% of birth weight difference was taken as inclusive criteria of BDT. BDT were divided into preterm or full-term groups,and low birthweight or normal birthweight groups respectively. SPSS 19.0 software was used for statistical analysis. RESULTS: A total of 141 pairs of BDT were included,accounting for 15.4%(141/916). The degree of birthweight difference in premature BDT was higher than that of full-term BDT(t=3.820,P<0.001). The growth discordance of preterm BDT lasted longer. Physical growth of low/very low birthweight BDT was slower than that of normal birthweight BDT under 4 years old. The growth status of BDT didn't reach the average level of WHO growth chart by the time of the last follow-up. CONCLUSION: Birthweight discordance of twins could have longlasting effects on further growth and development. Preterm twins have higher degree of birthweight discordance,and the growth discordance lasts longer. Low birthweight is an important reason for growth retardation of the lighter BDT.Growth of BDT should be monitored regularly to increase follow-up compliance.

Objective The dense fibrous connective tissue that connects sub-occipital muscles which consist of the rectus capitis posterior minor muscle (RCPmi), rectus capitis posterior major muscle (RCPma), obliquus capitis inferior muscle (OCI) and nuchal ligament (NL) to the spinal dura mater (SDM), is described as the myodural bridge (MDB) in humans. The MDB is perceived as an essential anatomical structure and has been a subject of interest for clinicians. Studies have revealed that MDB may be related to the dynamic circulation of the cerebrospinal fluid (CSF) and a chronic cervicogenic headache. To date, the MDB is identified as a universal, existing structure in mammals and it exists in other vertebrates as well, such as Gallus domesticus and Rock pigeons in Avifauna, Siamese crocodile and Trachemys scripta elegans in Reptile. The current study is to further analyze different structures features of the MDB in sundry classes and provide the anatomical basis for functional studies. The JapaLura Splendida is the most common species in Lacertiformes, Reptilia. So we chose it as the experimental object to supply the morphological study of the MDB in Reptilia. Methods The study was based on gross anatomical dissection, thick sheet section, histological staining to observe the structural characteristics of the post-occipital area of twenty JapaLura Splendidas and the existence of the MDB. Results The deep post-occipital muscles were composed of the rectus capitis dorsal muscle (RCD) and the obliquus capital posterior (OCP) muscle. The RCD was merged by the rectus capitis dorsal major muscle (RCDma), the rectus capitis dorsal minor muscle (RCDmi) and the obliquus capitis anterior muscle (OCA). In the atlanto-occipital space, the dense fibrous bundles were found to originate from the ventral aspect of the RCD and run ventral, closely inserting into the SDM. In the atlanto-axial space, the dense fibrous bundles were found to originate from the ventral aspect of the OCP and run ventral, closely contacted with the SDM. These dense fibrous bundles were the collagen type I fibers with strong double refraction. Conclusion The result of this study indicates that the MDB is located between the post-occipital muscles and the SDM in JapaLura Splendida. The MDB of Japalura splendida may be related to the activities of the head and neck, and exert a physiological function similar to the MDB in humans.

Objective To explore early postoperative gait characteristics and clinical outcomes after total knee arthroplasty(TKA).Methods From February 2023 to July 2023,26 patients with unilateral knee osteoarthritis(KOA)were treated with TKA,including 4 males and 22 females,aged from 57 to 85 years old with an average of(67.58±6.49)years old;body mass in-dex(BMI)ranged from 18.83 to 38.28 kg·m-2 with an average of(26.43±4.15)kg·m-2;14 patients on the left side,12 pa-tients on the right side;according to Kellgren-Lawrence(K-L)classification,6 patients with grade Ⅲ and 20 patients with grade Ⅳ;the courses of disease ranged from 1 to 14 years with an average of(5.54±3.29)years.Images and videos of standing up and walking,walking side shot,squatting and supine kneeling were taken with smart phones before operation and 6 weeks after operation.The human posture estimation framework OpenPose were used to analyze stride frequency,step length,step length,step speed,active knee knee bending angle,stride length,double support phase time,as well as maximum hip flexion angle and maximum knee bending angle on squatting position.Western Ontario and McMaster Universities(WOMAC)arthritis index and Knee Society Score(KSS)were used to evaluate clinical efficacy of knee joint.Results All patients were followed up for 5 to 7 weeks with an average of(6.00±0.57)weeks.The total score of WOMAC decreased from(64.85±11.54)before op-eration to(45.81±7.91)at 6 weeks after operation(P＜0.001).The total KSS was increased from(101.19±9.58)before opera-tion to(125.50±10.32)at 6 weeks after operation(P＜0.001).The gait speed,stride frequency and stride length of the affected side before operation were(0.32±0.10)m·s-1,(96.35±24.18)steps·min-1,(0.72±0.14)m,respectively;and increased to(0.48±0.11)m·s 1,(104.20±22.53)steps·min-1,(0.79±0.10)m at 6 weeks after operation(P＜0.05).The lower limb support time and active knee bending angle decreased from(0.31±0.38)sand(125.21±11.64)° before operation to(0.11±0.04)s and(120.01±13.35)° at 6 weeks after operation(P＜0.05).Eleven patients could able to complete squat before operation,13 patients could able to complete at 6 weeks after operation,and 9 patients could able to complete both before operation and 6 weeks after operation.In 9 patients,the maximum bending angle of crouching position was increased from 76.29° to 124.11° before operation to 91.35° to 134.12° at 6 weeks after operation,and the maximum bending angle of hip was increased from 103.70° to 147.25° before operation to 118.61° to 149.48° at 6 weeks after operation.Conclusion Gait analysis technology based on artificial intelligence image recognition is a safe and effective method to quantitatively identify the changes of pa-tients'gait.Knee pain of KOA was relieved and the function was improved,the supporting ability of the affected limb was im-proved after TKA,and the patient's stride frequency,stride length and stride speed were improved,and the overall movement rhythm of both lower limbs are more coordinated.

Objective: To investigate the association between trimethylamine-N-oxide (TMAO) and the degree of coronary atherosclerosis in coronary heart diseases (CHD) patients with type 2 diabetes mellitus. Methods: Consecutive patients, who underwent coronary angiography due to suspected CHD in Beijing Hospital from November 2016 to January 2018, were screened in this cross-sectional study. According to blood glucose level, previous medical history and coronary angiography results, they were divided into CHD without type2 diabetes mellitus(CHD-nDM) group and CHD with type2 diabetes mellitus(CHD-DM) group. Plasma TMAO levels in each group were measured by LC-MS/MS. Spearman correlation analysis was used to evaluate the correlation between TMAO and the number of diseased vessels and Gensini scores. Multivariate logistic regression was used to analyze the correlation between TMAO and high Gensini scores. Results: A total of 590 patients were enrolled in the study, including 238 patients in CHD-DM group and 352 patients in CHD-nDM group. Patients were older, body mass index, blood pressure level, prevalence of history of hypertension and statins use were higher in CHD-DM group than in CHD-nDM group (all P<0.05). The proportion of patients with multivessel disease (2 or more vessels) was also higher in CHD-DM group than in CHD-nDM group (P<0.001). Gensini score was higher in CHD-DM group than in CHD-nDM group (P<0.05). Fasting blood glucose, glycosylated hemoglobin and urea were significantly higher, while low-density lipoprotein cholesterol and hemoglobin were significantly lower in CHD-DM group than in CHD-nDM group (all P<0.05). The levels of TMAO was significantly higher in CHD-DM group than in CHD-nDM group (P<0.001). Spearman correlation analysis showed that TMAO was positively correlated with the number of diseased vessels, Gensini score, age and blood glucose level (r=0.178, 0.189, 0.260, 0.111, respectively, all P<0.01). Multivariate logistic regression analysis showed that, TMAO level was still positively correlated with high Gensini score in CHD-DM group (OR=2.25, 95%CI 1.16-4.38, P=0.017), but not in CHD-nDM group (OR=1.29, 95%CI 0.72-2.31, P=0.386) after adjusting for age, sex, body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol, triglyceride, history of hypertension, hyperlipidemia, smoking and statin use. Conclusions: In CHD patients with tupe 2 diabetes mellitus, the plasma TMAO level is significantly increased and is independent and positively correlated with the degree of coronary artery disease.