Imaging and Intracellular Analysis of Synaptic Plasticity in Spinal Dorsal Horn

点击翻译按钮获取中文摘要

1. Imaging of voltage response of marginal cell in the lamina I of the dorsal horn retrogradely stained with voltage-sensitive dye.Projection neurons in the lamina I were stained by voltage-sensitive dye that was injected in the thalamus or brain stem. After one week of the dye injection, slices of the spinal cord were made and the stained cells were recorded by an optical imaging method. The electrical activities evoked by dorsal root stimulation was successfully recorded optically with high resolution in both time and space. The action potentials and the after potentials were clearly observed. We are currently investigating the underlying mechanism of de-potentiation of LTP with this preparation.2. Modulation of dorsal horn plasticity induction by corticotropin releasing factor (CRF)We have searched substances that regulate induction of dorsal plasticity, which takes an important role in the induction of abnormal pain. We have found that CRF biphasically regulates the induction of robust changes in neuronal excitation in the superficial dorsal horn by optical imaging.3. Optical analysis of changes in extracellular space : Possible role for non-synaptic transmission.Intrinsic optical signals (IOS) in slice has been suggested to reflect cellular volume or extracellular space. We have revealed that cotransporters and water channels play the major role for the IOS induction in the superficial dorsal horn. We are currently investigating on their modulators and the changes in electrical activities associated with the volume changes by optical imaging.4. Optical analysis of presynaptic modulation at the primary afferent terminals.By optical imaging, we were able to record presynaptic events, and we investigated on the modulators. We analysed the presynaptic actions of halothane and caffeine as well as vanilloid receptor agoninsts.