Visualizing hippocampal synaptic function by optical detection of Ca super(2+) entry through the N-methyl-D-aspartate channel

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 91; no. 17; pp. 8170 - 8174
• Main Authors: Malinow, R, Otmakhov, N, Blum, KI, Lisman, J
• Format: Journal Article
• Language: English
• Published: 01.01.1994
• ISSN: 0027-8424

Fura-2 and imaging technology were used to detect intracellular Ca super(2+) changes in CA1 pyramidal cells in hippocampal slices. During focal synaptic stimulation, one or more highly localized regions of Ca super(2+) elevation (hot spots) were detected in the dendrites. Ca super(2+) spread from the center of hot spots with properties consistent with diffusion. Several lines of evidence indicate that these hot spots were due to Ca super(2+) entry through N-methyl-D-aspartate synaptic channels. The spatial and temporal resolution of the method was sufficient to detect the response of single hot spots to single stimuli, thus providing a real-time method for monitoring local synaptic activity. Using this method, we show that synapses on the same dendrite differ in their probability of response and in their facilitation properties.