Simon Xuan Chen

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The motor cortex is capable of reliably driving complex movements yet exhibits considerable plasticity during motor learning. These observations suggest that the fundamental relationship between motor cortex activity and movement may not be fixed but is instead shaped by learning; however, to what extent and how motor learning shapes this relationship are(More)
Cell adhesion molecules are well characterized for mediating synapse initiation, specification, differentiation, and maturation, yet their contribution to directing dendritic arborization during early brain circuit formation remains unclear. Using two-photon time-lapse imaging of growing neurons within intact and awake embryonic Xenopus brain, we examine(More)
Natural sensory input shapes both structure and function of developing neurons, but how early experience-driven morphological and physiological plasticity are interrelated remains unclear. Using rapid time-lapse two-photon calcium imaging of network activity and single-neuron growth within the unanesthetized developing brain, we demonstrate that visual(More)
PURPOSE To evaluate the long-term safety and efficacy of a new technique using a modified cow-hitch knot for transscleral suture fixation of posterior chamber intraocular lenses (PC IOLs). SETTING Public hospital in Brisbane, Australia. METHODS A retrospective chart review was conducted of consecutive patients who had transscleral sutured PC IOL(More)
Motor skill learning induces long-lasting reorganization of dendritic spines, principal sites of excitatory synapses, in the motor cortex. However, mechanisms that regulate these excitatory synaptic changes remain poorly understood. Here, using in vivo two-photon imaging in awake mice, we found that learning-induced spine reorganization of layer (L) 2/3(More)
OBJECTIVE To investigate the usefulness of a novel retinoic acid receptor (RAR) antagonist (BMS-189453) in animal models of arthritis. METHODS BMS-189453 was tested in HIG-82 rabbit synovial fibroblasts to determine its ability to repress collagenase (matrix metalloproteinase-1, MMP-1) mRNA expression in vitro. Cells were stimulated with phorbol myristate(More)
The immature brain is exceptionally susceptible to seizures. However, it remains unclear whether seizures occurring during development affect critical processes underlying neural circuit formation, leading to long-term functional consequences. Here we characterize a novel in vivo model system of developmental seizures based on the transparent albino Xenopus(More)
BACKGROUND/AIMS Bone marrow-derived mesenchymal stem cells (BMSCs) have the ability to differentiate into multilineage cells such as osteoblasts, chondrocytes, and cardiomyocytes. Dysfunction of BMSCs in response to pathological stimuli participates in the development of diseases such as osteoporosis. Astragalus polysaccharide (APS) is a major active(More)
PURPOSE To evaluate the efficacy and safety of long-term application of autologous serum eye drops treating recalcitrant dry eye syndrome. METHODS A retrospective chart review was conducted of patients who had serum eye drops between May 2001 and March 2006. The clinical data collected included sex, age, indications for serum eye drops, frequency of(More)