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Eight-year medical education is to train medical personnel with high research abi lity and innovative ability, while the experimental teaching, as an important part of physiology teaching, plays an important role in training students in observation, problem-solving skills and practical ability. This article mainly discusses our exploration and practice of teaching in physiology experiment for eight-year program medical students from teaching contents and organization of class teaching, in order to fully increase the studying enthusiasms and meet the scientific mind of these students.
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It is well believed that learning and memory is one of the functions of sleep.Not only does the sleep after learning aid memory consolidation, but enough sleep before learning is necessary for memory formation.Due to the net increase in synaptic strength, waking plasticity has a cost in terms of energy requirements, space requirements, and progressively saturates the capacity to learning.The review will focus on the role of sleep which is to downscale synaptic strength to a baseline level that is beneficial for learning and memory.
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Sleep and memory are the basic function of the brain. A large number of studies from both humans and animals experiments have offered a substantive body of evidence supporting that sleep contributes crucially to memory consolidation. The processes of memory consolidation in hippocampus and cortex during sleep was reviewed and the primary cellular and molecular mechanism were briefly introduced.
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Objective To observe the time course of the changes in nitric oxide (NO) content and the activity of NO synthase (NOS) during hippocampal long term potentiation (LTP) in vitro . Methods The production and maintenance of LTP were detected by using extracelluar electrophysiological recording. NO content and NOS activity were determined by biochemical reaction. The expression of NOS mRNA was detected by in situ hybridization. Results Conditioning stimulation for 10 min induced LTP production and significant increases in NO content, NOS activity and expression of NOS mRNA. However, at 60 min after conditioning stimulation, LTP remained stably but NO content and NOS activity returned to the pre conditioning stimulation level. Moreover, the NOS mRNA was overexpressed at the early stage of LTP production. Conclusion Significant NO changes may occur at the early stage of LTP formation.
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Objective To investigate the effect of exogenous orexinA on the pyramid neurons and interneurons in the prefrontal cortex prelimbic(PL)area.Methods The pyramid neurons and interneurons in PL area of Kunming mice were selected from prefrontal cortex slices by infrared visual patch clamp technique.The morphology and electrophysiological features of the pyramid neurons and interneurons were observed.The effect of exogenous orexinA at a concentration of 400 nmol/L on these cells was studied using the whole cell configuration.Results The pyramid neurons were large,pyramidal in cell body with clear apical dendrites extending vertically and several basal dendrites radiating.The interneurons were comparatively smaller and had several processes from cell body.In current clamp mode,all 54 pyramid neurons having been recorded showed frequency adaption,and the 15 recorded interneurons discharged rapidly and had no frequency adaption.While in vol-tage clamp mode,36 pyramid neurons were regarded as Ih(+)pyramid neurons for recorded hyperpolariztion-activated cation current,and the left 18 and 15 interneurons were Ih(-).Exogenous orexinA had a total reaction rate of 51.9% on 54 recorded pyramid neurons under current clamp,and a rate of 66.7% on 36 Ih(+)pyramid neurons and of 22.2% on the Ih(-)pyramid neurons under voltage clamp.All 15 recorded interneurons had no reaction to exogenous orexinA under either mode.Conclusion OrexinA plays excitatory effect on pyramid neurons in the prefrontal cortex PL area,and this effect is much more noticeable in pyramid neurons with Ih currents.
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Objective To investigate the modulatory effect of orexin A on glutamate receptor-mediated current in the freshly isolated pyramidal neurons from the rat prefrontal cortex (PFC). Methods Deep layer (Ⅴ-Ⅵ) prefrontal cortical pyramidal neurons from postnatal 10 to 14 day-old Wistar rats were acutely dissociated by a combination of mechanical and enzymatic method. Subsequently, the effect of orexin A on the current induced by glutamate was studied by the technique of whole cell patch clamp. Results Both orexin A and glutamate dose-dependently evoked the inward transmembrane current. The current was evoked by 1 mmol/L glutamate as a control group(100%). After treatment with 1 mmol/L orexin A for 4-10 s, 1 mmol/L glutamate induced-current was increased by (46.59?15.19)% (n=8, P
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Objective To observe the effects of NMDA receptors and nitric oxide (NO) on neural cell adhesion molecule(NCAM) synthesis during hippocampal long term potentiation (LTP) induction in vitro . Methods LTP induction and maintenance were tested by using extracelluar electrophysiological recording. The synthesis of NCAM protein was detected by Western blotting. Results Application of conditioned stimulation induced LTP and a rise in NCAM at 10 min. NCAM protein level continued to rise while LTP remained stably at 60 min. The NMDA receptor inhibitor AP 5 and the NO synthase inhibitor N nitro arginine inhibited the LTP induction and the increase in the NCAM synthesis. Conclusion The changes in NCAM synthesis during hippocampal LTP induction in vitro may be involved in NMDA receptors and NO.