Enriched environments promote synaptic remodeling in the hippocampus by activating the Wnt/β-catenin signaling pathway / 中华物理医学与康复杂志

Objective:To explore how an enriched environment promotes synaptic remodeling in the hippocampus after cerebral ischemia.Methods:Among 60 clean, adult, male C57BL/6 mice, 16 were randomly selected into a sham operation group, while the remaining 44 underwent permanent left middle cerebral artery embolization. The 32 mice with successful modeling were randomly divided into a normal environment group and an enriched environment group, each of 16. The enriched environment group lived in an enriched environment for 28 days, while the other two groups were raised in normal conditions. The number of synapses in the CA3 area of the hippocampus was then measured using transmission electron microscopy, and the expression of Wnt7a, Dvl1, β-catenin, synaptophysin (SYN) and PSD-95 in the hippocampus were measured using western blotting.Results:Compared with the normal environment group, the average protein expression levels of Wnt7a, Dvl1, β-catenin, SYN and PSD-95 were all significantly higher in the enriched environment group. The number of synapses in the CA3 region of the enriched environment group was also significantly higher than in the normal environment group.Conclusion:An enriched environment can activate the Wnt7a-β-catenin-Dvl1 signaling pathway in the hippocampus after cerebral ischemia to promote synaptic remodeling, at least in mice.

An enriched environment enhances synaptic plasticity and cognition post-stroke / 中华物理医学与康复杂志

Objective To observe the effects of an enriched environment (EE) on cognitive functioning and the synaptic plasticity of mice modeling post-stroke cognitive impairment (PSCI) and explore the possible mechanisms involved.Methods Mice modeling PSCI and sham-operated mice were randomly divided into 3 groups:sham-operated mice in a standard environment (the Sham+SE group),PSCI mice in a standard environment (the PSCI+SE group) and PSCI mice in an enriched environment (the PSCI+EE group).The cognitive functioning of all of the mice was quantified using a Morris water maze and their hippocampal long-term potentiation (LTP) was recorded using an electrophysiological method.The level of synaptophysin was detected using Western blotting.Synaptic ultrastructure in the hippocampus was imaged using electron microscopy.Results Compared with the Sham +SE group,the PSCI+SE group showed significantly poorer water maze performance and failed induction of contralateral LTP.Their average level of synaptophysin was significantly lower,and significant adverse changes in the synaptic ultrastructure of the hippocampus were observed,including a decreased number of synapses.The average width of the synaptic cleft,postsynaptic density and the interface curvature of the synapses were all less desirable.All of the measurements of the PSCI+EE group improved significantly compared to those of the PSCI+SE group,but were still significantly poorer than those of the Sham+SE group.Conclusions An enhanced environment can improve the cognitive functioning of mice modelling PSCI.It may be that an EE can improve synaptic plasticity in the hippocampus contralateral to the stroke.

The effects of an enriched environment on psychological and behavioral symptoms of senescence / 中华物理医学与康复杂志

Objective To investigate the effects of an enriched environment (EE) on the psychological and behavioral symptoms of senescence and on the level of plasmic adrenocorticotropic hormone (ACTH) and serum corticosteroid (Cor). MethodsTwenty male senescence-prone SAMP8 mice of 3 months old were divided randomly into an enriched environment (EE) group and a standard environment (SE) group.Five male senescence-resistant SAMR1 mice of the same age served as the control group.Behavioral symptoms were assessed after 2 months using autonomic activity and elevated-plus maze (EPM) test performance.Plasma ACTH and serum Cor were detected using radio-immunologic methods. ResultsAverage autonomic activity frequency and EPM open-arm times were significantly lower with the SAMP8 mice than among the control group,and the autonomic activity frequency was significantly higher in the EE group than in the SE group of SAMP8 mice.The average EPM open-arm times of the EE group and the SE were not significantly different.Average ACTH and Cor levels were both significantly lower in the SAMP8 mice,and the level of ACTH was significantly higher in the EE group than in the SE group.There was no significant difference in these groups' average Cor levels. ConclusionsThe SAMP8 mice of 5 months demonstrated significant mental and behavioral abnormalities,as well as down-regulated plasma levels of ACTH and Cor.EE An enhanced environment can reduce behavioral disturbance through up-regulating ACTH.

The effects of light intensity on the voluntary exercise level of rats in an enriched environment / 中华物理医学与康复杂志

Objective To study the effects of light at different intensities and an enriched environment (EE) on rats' level of voluntary exercise,and to explore the resulting benefits.Methods Thirty male SpragueDawley rats were tested successively under 4 different experimental conditions:EE + strong light,EE + dim light,open-field environment (OFE)+ strong light and OFE + dim light.Each rat's path in the different conditions was recorded using an automated tracking system.Distance moved (m),velocity (m/s),mobile duration (s),mobile frequency,moving duration (s) and moving frequency were recorded over a one-hour period. ResultsThe EE rats were significantly more active than the OFE rats in both strong and dim light.All rats were more mobile under dim light than under strong light.Conclusion Environment and light intensity are independent factors affecting rats' voluntary exercise levels,and they can exert their influence in synergy.

The effect of errorless learning on memory process for patients with brain injury:An initial study / 中华物理医学与康复杂志

Objective To evaluate the effect of errorless learning on memory processes.Methods Eight- y-four participants were randomly divided into three groups:a group which received computer-assisted memory train- ing (CAMG,n=30) ,a therapist-administered memory training group (TAMG,n=24) and a control group (CG,n =30).A 20-session training course with a Chinese cultural background was tailor-made for Chinese subjects with memory disorders.It was administered over the course of one month to the test groups with a similar course structure and content but different delivery modes.The control group had no training.The Rivermead Behavioral Memory Test- Chinese Version (RBMT-CV) and the Hong Kong List Learning Test (HKLLT) were used to assess memory ability and process at the start and end of the training,and one month later.A repeated measures analysis of variance was used to compare differences across the three groups.Results Comparing pre-training with post-training and follow- up,RBMT-CV and HKLLT scores improved significantly.The CAMG group demonstrated better progress encoding and storage on the HKLLT (including the random and blocked conditions) than the TAMG group.Conclusions Errorless learning is likely to be an effective technique for improving memory function in patients with traumatic brain injury.Its effects last for at least one month.Computer-administered training was more effective than therapist-admin- istered face to face training,especially in improving encoding and storage memory processes.