NEUROTRANSMITTER IMAGING IN LIVING CELLS BASED ON NATIVE FLUORESCENCEDETECTION

A UV laser-based optical microscope and CCD detection system with high sensitivity has been developed to image neurotransmitters in living c ells. We demonstrate the detection of serotonin that has been taken up into individual living glial cells (astrocytes) based on its native f luorescence. We found that the fluorescence intensity of astrocytes in creased by up to 10 times after serotonin uptake. The temporal resolut ion of this detection system at 10(-4) M serotonin is as fast as 50 ms , and the spatial resolution is diffraction limited. This UV laser mic roscope imaging system shows promise for studies of spatial-temporal d ynamics of neurotransmitter levels in living neurons and glia.