Newly developed intravital cell imaging and its application for brain science

Mounting evidences indicate that the calcium ion and reactive oxygen species (ROS) play key rolesmany diseases of the brain. Most of them have been studied using cultured cells. Howeverin whole animals，calcium response and the production of ROS following ischemia remains to be established，因为no method has been available to measure the [Ca^<2+>]_i and ROS in the brain of livinganimals. In the present study, we sought to determine, In ratsthe production of ROS following brain ischemia；and 2) the [Ca^<2+>]_i changes following transient forebrain ischemia in hippocampus. in addition，during photodynamic therapy （PDT）we sought to monitor the production of singlet oxygen (^ 1_2), one of the ROSrat glioma. The results in The present project must be useful to examine The cellular mechanismin situ,and thereby valuable to develop the methods for the treatment of the brain disease including1) We established a new semi-quantitativ…e分析系统that can spatiotemporally detect the cortical intracellular productionROS. ischemia /reperfusion-dependent production of superoxide radical (o_2 ^-) and hydroxylradical were measured by intravital imaging using fluorescence dye. The result indicated thato_2 -和OH production increased in the early period of reperfusion but not during the ischemia.2To determine, in ratsthe [Ca^<2+>]_i changes following transient forebrain ischemia in hippocampus，我们雇用一个fiber-coupled confocal microscope to observe the confocal images in hippocampus. inCA1, but not in CA3，transient forebrain ischemia induced long lasting [Ca^<2+>]i increase in situ. Since the [Ca^<2+>]increase was significantly larger in CA1 during reperfusion period，这可能涉及到toxic levels，然后mediate the vulnerability of CA1 against ischemia.3) Using anew near infrared-photomultiplier tube系统我们monitored the real-time production of 1_2 during PDT and investigated the relationship betweenthe 1_2 production and photodynamic effects. Our results indicated that the optimal condition ofirradiation should be decided based on the ^ 1_2 generation. Less

Mounting evidences indicate that the calcium ion and reactive oxygen species (ROS) play key roles in many diseases of the brain. Most of them have been studied using cultured cells. However, in whole animals, calcium response and the production of ROS following ischemia remains to be established, since no method has been available to measure the [Ca^<2+>]_i and ROS in the brain of living animals. In the present study, we sought to determine, in rats, 1) the production of ROS following brain ischemia ; and 2) the [Ca^<2+>]_i changes following transient forebrain ischemia in hippocampus. In addition, 3) during photodynamic therapy (PDT), we sought to monitor the production of singlet oxygen (^1O_2), one of the ROS, in rat glioma. The results in the present project must be useful to examine the cellular mechanism in situ, and thereby valuable to develop the methods for the treatment of the brain disease including cerebral infarction and brain tumor.1) We established a new semi-quantitativ … More e analysis system that can spatiotemporally detect the cortical intracellular production of ROS. Ischemia/reperfusion-dependent production of superoxide radical (・O_2^-) and hydroxyl radical (・OH) were measured by intravital imaging using fluorescence dye. The result indicated that ・O_2^- and・OH production increased in the early period of reperfusion but not during the ischemia.2) To determine, in rats, the [Ca^<2+>]_i changes following transient forebrain ischemia in hippocampus, we employed a fiber-coupled confocal microscope to observe the confocal images in hippocampus. In CA1, but not in CA3, transient forebrain ischemia induced long lasting [Ca^<2+>]i increase in situ. Since the [Ca^<2+>]_i increase was significantly larger in CA1 during reperfusion period, it might reach to toxic levels and then mediate the vulnerability of CA1 against ischemia.3) Using a new near infrared-photomultiplier tube system, we monitored the real-time production of ^1O_2 during PDT and investigated the relationship between the ^1O_2 production and photodynamic effects. Our results indicated that the optimal condition of irradiation should be decided based on the ^1O_2 generation. Less