Monitoring of neuronal and glial calcium activity using a novel direct-contact probe

In vivo neuronal and glial calcium activity was monitored using a novel direct-contact probe that was designed for fluorescence detection deep within biological tissue. A small diameter fibre bundle direct-contact probe was employed with a laser scanning confocal microscope to detect evoked neuronal and glial activity in the posteromedial barrel subfield of the rat somatosensory cortex in vivo. Resolution of the probe allowed discrimination of single cells, and calcium dynamics spanning milliseconds to several seconds were observed. Initial results indicate that the probe has useful practical applications in the imaging of individual cells and monitoring rapid calcium fluctuations within their cell body and large processes.