ABSTRACT
AIM:To investigate the effects of cordycepin on the motor and cognition in Parkinson disease mice induced by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP).METHODS:C57BL/6 mice were intraperitoneally injected with MPTP at a dose of 30 mg/kg daily for consecutive 8 d to establish the model of Parkinson disease.HE staining was used to observe the cell number in the substantia nigra pars compacta (SNpc) from the mice.Western blot was used to detect the protein level of tyrosine hydroxylase (TH) in substantia nigra (SN).The effects of cordycepin on the motor, emotional change and cognitive behavior of the Parkinson disease mice were examined by open-field test (OFT) , spontaneous alternating behavior (SAB) and water maze test (WMT) , respectively.RESULTS:Cordycepin significantly reduced the apoptosis of cells in SNpc and reversed the decrease in the expression of TH in SN induced by MPTP (P<0.05).Furthermore, cordycepin was able to improve the average speed in OFT (P<0.05) , and increased the total number of arm entry and the accuracy in SAB (P<0.05) , but had no obvious effect on the latency in WMT.CONCLU-SION:Cordycepin is capable of attenuating the impairments of motor and explorative ability in the early stage of Parkinson disease mice, but does not alter the cognitive dysfunction.
ABSTRACT
PURPOSE: Modafinil is a wake-promoting agent that has been proposed to improve cognitive performance at the preclinical and clinical levels. Since there is insufficient evidence for modafinil to be regarded as a cognitive enhancer, the aim of this study was to investigate the effects of chronic modafinil administration on behavioral learning in healthy adult rats. METHODS: Y-maze training was used to assess learning performance, and the whole-cell patch clamp technique was used to assess synaptic transmission in pyramidal neurons of the hippocampal CA1 region of rats. RESULTS: Intraperitoneal administration of modafinil at 200 mg/kg or 300 mg/kg significantly improved learning performance. Furthermore, perfusion with 1mM modafinil enhanced the frequency and amplitude of spontaneous postsynaptic currents and spontaneous excitatory postsynaptic currents in CA1 pyramidal neurons in hippocampal slices. However, the frequency and amplitude of spontaneous inhibitory postsynaptic currents in CA1 pyramidal neurons were inhibited by treatment with 1mM modafinil. CONCLUSIONS: These results indicate that modafinil improves learning and memory in rats possibly by enhancing glutamatergic excitatory synaptic transmission and inhibiting GABAergic (gamma-aminobutyric acid-ergic) inhibitory synaptic transmission.
Subject(s)
Adult , Animals , Humans , Rats , CA1 Region, Hippocampal , Excitatory Postsynaptic Potentials , Inhibitory Postsynaptic Potentials , Learning , Memory , Neurons , Perfusion , Synaptic Potentials , Synaptic TransmissionABSTRACT
<p><b>AIM</b>To study the effects of yi-zhi II (a compond of Chinese Traditional Medicine) on the alteration of synaptic structure in hippocampal CA3 and maintenance of memoy.</p><p><b>METHODS</b>By using the method of oral administration of yi-zhi II, the step-through test and electron microscopy, the latency of step-through and synaptic structure in hippocamal CA3 were tested.</p><p><b>RESULTS</b>(1) The mice which had been given yi-zhi II prolong significantly the latency of step through (P < 0.05 or P < 0.01) on the 1st, 6th and 12th day after learning. (2) On the 6th and 12th day after learning, the length of synaptic active zone were markly improved in yi-zhi II and control, but that of yi-zhi II was better than that of control. (On the 6th day after learning, the number of perforated synapses and axo-dendrite synapses were significantly improved by the yi-zhi II (P < 0.05).</p><p><b>CONCLUSION</b>The yi-zhi II could improve the learning and memory in mice. It migth improve the memory by increasing the length of synaptic active zone and the number of perforated synapses and axo-dendrite synapses in hippocampal CA3.</p>