Objective To observe the local field potential activity of dorsomedial and dorsolater striatal (STR) neurons in rats with exercise-induced fatigue,so as to explore the regional characteristics of those neurons.Methods Thirty-six male Wistar rats were randomly divided into a control group(CG),a single fatigue group(SFG)and a repeated fatigue group(RFG),each of 12.The exercise-induced fatigue model was established according to a load-increasing treadmill running protocol.The CG did not do any treadmill running,SFG finished one-time exhaustive exercise while the RFG repeated exhaustive exercise 6 times.The extracellular glass microelectrode technique was used to record the spontaneous firing of dorsomedial(n=6)and dorsolateral(n=6)STR neurons in vivo to observe the discharging frequency,characteristics and types.Results (1)Spontaneous firing frequencies of striatal neurons in SFG were significantly higher than those of CG(P＜0.01),while those of RFG were significantly lower than SFG.(2) After repeated fatigues,there were significant decreases in the irregular firing pattern and significant increase in the explosive firing of striatal neurons compared with CG(P＜0.05).(3)After the single fatigue and repeated fatigue,the discharging frequency of dorsomedial medium spiny-like neurons increased significantly(P＜0.05),and that after repeated fatigue significantly higher than that of the dorsolateral(P＜0.01).The discharge frequency of the dorsomedial and dorsolateral fast-spiking neurons decreased significantly after repeated fatigues.The discharge frequency of dorsolateral large aspiny-like neurons of RFG was significantly higher than SFG,while that of the latter was significantly lower than CG(P＜0.05).Conclusions (1)Striatal neurons mediate exercise-induced fatigue and present regional characteristics,which might be due to dorsomedial and dorsolateral striatal neurons receiving different types of projection neurons.(2) Striatal fast-spiking neurons may play an important role in mediating the exercise-induced fatigue.

Elastin is a natural biomedical material of great potential. Being endowed with the special crosslinking and hydrophobic structure, elastin retains many good properties such as good elasticity, ductibility, biocompatibility, biodegradability and so on. Nowadays, elastin as a material, which is gradually attracting people' s attention in the biomedical materials field, has been used as tissue engineering scaffolds, derma substitutes and other biomedical materials. In this context, a systematic review on the characteristics of elastin as a biomedical material and on the actuality of its application is presented. Future developments of elastin in the field of biomedical applications are also discussed.
Biocompatible Materials ; Elastin ; chemistry ; physiology ; Humans ; Skin, Artificial ; Tissue Scaffolds

BACKGROUND:Sarcopenia is a progressive,generalized skeletal muscle disease that is closely related to the occurrence of osteoarthritis,fractures,limb disability and death in the elderly.Establishing animal models of sarcopenia is essential to understand the pathophysiology of sarcopenia and to identify effective treatment strategies. OBJECTIVE:To review the evaluation criteria of mouse models of sarcopenia and the modeling methods of mouse models of sarcopenia,and to analyze and compare the advantages and disadvantages of various modeling methods,in order to provide reference for the research and diagnosis and treatment of sarcopenia. METHODS:"Sarcopenia,skeletal muscle aging,mouse model,animal model"in Chinese and English were used as Chinese and English search terms,respectively.The search formula was"(sarcopenia OR skeletal muscle aging)AND(mouse model OR animal model)."CNKI,WanFang and PubMed were searched for related articles published from January 2010 and October 2022.A total of 59 articles were finally included for analysis. RESULTS AND CONCLUSION:There is a faster modeling time in SAMP8 mice and the type of muscle atrophy is consistent with that of patients with sarcopenia.Therefore,it is an ideal model.Although the surgical method can successfully induce muscle atrophy,it requires precise surgical operation,which is difficult and time-consuming.Hindlimb suspension modeling in mice is similar to that of the elderly and can be regarded as an effective model of senile sarcopenia.Although reagent injection molding is simple to perform,both the dose and number of days of administration of reagents are not clear and need to be further investigated.Transgenic mouse models are less commonly used and their model stability needs further study.The search for a mouse model with low cost,short time consumption and high simulation of human sarcopenia is still a future research direction.