Send to

Choose Destination
Front Neuroanat. 2011 Jun 6;5:32. doi: 10.3389/fnana.2011.00032. eCollection 2011.

Imaging single photons and intrinsic optical signals for studies of vesicular and non-vesicular ATP release from axons.

Author information

Nervous Systems Development and Plasticity Section, National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA.


The temporal and spatial dynamics of neurotransmitter release are fundamental to understanding activity-dependent signaling between axons and other cells, including neurons, glia, and vascular cells. A microscopic imaging technique is described that enables studying release of the neurotransmitter ATP from axons in response to action potentials. The method combines imaging single-photons, intrinsic optical signal imaging, and high magnification time-lapse microcopy to enable investigations of action potential-induced ATP release together with cell morphology and activity-dependent axon swelling. ATP released from axons catalyzes a chemiluminescent reaction between luciferin and luciferase that generates single photons that can be imaged individually. In addition to vesicular release, ATP release through membrane channels activated by axon swelling was monitored simultaneously with intrinsic optical signals. Repeated emissions of photons were observed from localized 15 μm regions of axons, with a frequency distribution that differed from a normal distribution and from the frequency of emissions outside these localized regions.


activity-dependent development; axon swelling; axon volume; intrinsic optical signals; luciferase; neuron–glia interactions; neurotransmitter release; synaptic-vesicle release

Supplemental Content

Full text links

Icon for Frontiers Media SA Icon for PubMed Central
Loading ...
Support Center