ABSTRACT
Ras-related C3 botulinum toxin substrate 1 (Rac1), a member of the Rho GTPase family which plays important roles in dendritic spine morphology and plasticity, is a key regulator of cytoskeletal reorganization in dendrites and spines. Here, we investigated whether and how Rac1 modulates synaptic transmission in mouse retinal ganglion cells (RGCs) using selective conditional knockout of Rac1 (Rac1-cKO). Rac1-cKO significantly reduced the frequency of AMPA receptor-mediated miniature excitatory postsynaptic currents, while glycine/GABA receptor-mediated miniature inhibitory postsynaptic currents were not affected. Although the total GluA1 protein level was increased in Rac1-cKO mice, its expression in the membrane component was unchanged. Rac1-cKO did not affect spine-like branch density in single dendrites, but significantly reduced the dendritic complexity, which resulted in a decrease in the total number of dendritic spine-like branches. These results suggest that Rac1 selectively affects excitatory synaptic transmission in RGCs by modulating dendritic complexity.
ABSTRACT
@# ObjectiveTo study the effect and mechanisms of nourishing Piyin Remedy (nPR) and bovine brain extract (bBE) on experimental spinal cord injury (SCI) of rat.Methods80 healthy SD rats were divided into 5 equal groups randomly: bBE group supplied through subarachnoid cavity, normal saline (NS) group supplied through subarachnoid cavity, nPR group, NS orally taken group, combined group. Animal models were made by Allen's equipment on T8～T9 segment. The spinal nerve function, somatosensory evoked potentials (SEP), retrograde and label technique of horseradish peroxidase, gross observation, histological and morphometric analysis were taken as the observed indices.ResultsThe values of observed indices of bBE group and nPR group improved evidently compared with their own control groups; that of combined group was prior to sole administration.ConclusionnPR can hold back the secondary SCI and accelerate the recovery of spinal nerve function; bBE can stimulate the improvement of injuried nerve fibers; the joint of nPR and bBE can make a synergic effect.
ABSTRACT
@#ObjectiveTo study the therapeutic effect and mechanisms of nourishing Piyin Remedy (nPR) on experimental rat spinal cord injury.MethodsThirty-two healthy SD rats were divided into 2 equal groups randomly: nPR group and injured group. Animal model of incomplete injury of spinal cord was made by Allen's equipment on rat's T8—T9 segment. The spinal nerve function,SEP,retrograde and label technique of horse radish peroxidase,gross observation,histological and morphometric analysis were taken as the observed indices.ResultsThe value of observed indices of nPR group were improved evidently compared with injured group.ConclusionNourishing Piyin Remede can hold back the secondary spinal cord injury and accelerate the recovery of spinal nerve function.