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High-voltage spindles (HVSs) have been reported to appear spontaneously and widely in the cortical–basal ganglia networks of rats. Our previous study showed that dopamine depletion can significantly increase the power and coherence of HVSs in the globus pallidus (GP) and motor cortex of freely moving rats. However, it is unclear whether dopamine regulates HVS activity by acting on dopamine D1-like receptors or D2-like receptors. We employed local-field potential and electrocorticogram methods to simultaneously record the oscillatory activities in the GP and primary motor cortex (M1) in freely moving rats following systemic administration of dopamine receptor antagonists or saline. The results showed that the dopamine D2-like receptor antagonists, raclopride and haloperidol, significantly increased the number and duration of HVSs, and the relative power associated with HVS activity in the GP and M1 cortex. Coherence values for HVS activity between the GP and M1 cortex area were also significantly increased by dopamine D2-like receptor antagonists. On the contrary, the selective dopamine D1-like receptor antagonist, SCH23390, had no significant effect on the number, duration, or relative power of HVSs, or HVS-related coherence between M1 and GP. In conclusion, dopamine D2-like receptors, but not D1-like receptors, were involved in HVS regulation. This supports the important role of dopamine D2-like receptors in the regulation of HVSs. An siRNA knock-down experiment on the striatum confirmed our conclusion. [ABSTRACT FROM AUTHOR]

This study evaluated the role of gastrocnemius-derived brain-derived neurotrophic factor (BDNF) and possible mechanism in motor improvement in T10 spinal cord transection (SCT) rats. There was complete paralysis in hindlimbs immediately after SCT, followed by partial functional restoration with time going. The level of BDNF but not its mRNA gradually increased in caudal stump after SCT, whereas a significant increase in both BDNF and its mRNA was simultaneously seen in gastrocnemius. Injection of BDNF antibody into the gastrocnemius significantly decreased hindlimb locomotor function, downregulated the level of BDNF and its mRNA together with extracellular signal-regulated kinase 1/2 (Erk1/2). Moreover, ventral root ligation led to decrease both BDNF and Erk in caudal stump, indicating BDNF transportation from gastrocnemius into the spinal cord. We concluded that gastrocnemius-derived BDNF reduced motor functional deficits in SCT rats through Erk signaling pathway. These novel findings suggested the usage of BDNF in muscle for the treatment of spinal cord injury in clinic. [ABSTRACT FROM AUTHOR]

Abstract: The clinic treatment of epilepsy with epileptic foci overlapped with eloquent cortex is not satisfactory. In this study we investigated the direct effects of low- and high-frequency electric cortical stimulation (ECS) on ferric chloride-induced seizures in the experimental rats. Results showed that spontaneous seizures were observed in all rats during the EEG recording after the intracortical injection of ferric chloride solution into left sensorimotor cortex. One-hertz or 100-Hz ECS with 0.3ms duration and 0.1mA amplitude square pulses in 1h on the cortical lesioned area significantly decreased the number of seizures compared with that of the non-stimulation control group. The mean duration time of seizures in 1-Hz or 100-Hz groups was apparently shorter than that in the control group. In brief, this study showed that both low- and high-frequency ECS suppressed the seizures induced by ferric chloride in rats, indicating their potential treatment effects on epilepsy in clinic. [Copyright &y& Elsevier]

Abstract: Lanthanum is one of rare earth cations with extremely active chemical property and has been reported to influence neuronal transmitter systems. To date, little attention has been directed towards the sacral dorsal commissural nucleus (SDCN), which serves as a relay of sensory information from the pelvic viscera in the spinal cord. Therefore, the effect of lanthanum on the inhibitory neurotransmitter γ-aminobutyric acid (GABA) and glycine (Gly) responses in neurons acutely dissociated from the rat SDCN was investigated using the nystatin-perforated patch-recording configuration under voltage-clamp conditions. At a holding potential of −40 mV, La3+ reversibly potentiated GABA (3 μM)-activated currents (I GABA) in a concentration-dependent manner over the concentration range of 10 μM to 30 mM, with the EC50 value of 67.3±16.4 μM. Similarly, La3+ reversibly potentiated glycine (10 μM)-activated currents (I Gly) in a concentration-dependent manner over the concentration range of 1 μM to 1 mM, with the EC50 value of 52.3±10.9 μM. The effects of La3+ on I GABA and I Gly were voltage-independent. Moreover, both of the potentiations were not use-dependent and were overcome by increasing the concentration of agonist. Our results indicate that La3+ potentiates the inhibitory amino acid receptors-mediated responses in SDCN, which may reduce the transmission of the pelvic visceral information. The information provided by this work may help to elucidate the mechanisms and effects of lanthanum on brain functions. [Copyright &y& Elsevier]