UNIT 6.21 Photolysis of Caged Neurotransmitters: Theory and Procedures for Light Delivery

  1. Cha-Min Tang

Published Online: 1 NOV 2006

DOI: 10.1002/0471142301.ns0621s37

Current Protocols in Neuroscience

Current Protocols in Neuroscience

How to Cite

Tang, C.-M. 2006. Photolysis of Caged Neurotransmitters: Theory and Procedures for Light Delivery. Current Protocols in Neuroscience. 37:6.21:6.21.1–6.21.12.

Author Information

  1. Baltimore VA Medical Center and University of Maryland School of Medicine, Baltimore, Maryland

Publication History

  1. Published Online: 1 NOV 2006
  2. Published Print: OCT 2006


Photolysis of “caged” compounds is a technique for releasing biologically active compounds in which the timing, rate, and spatial profile of release are controlled by light. Issues relating to the delivery of light for single-photon photolysis are presented. Specific discussions include the theories relating to how light interacts with biological tissue to produce scattering and phototoxicity, as well as the issues involved in choosing the appropriate light source. Several approaches and optical designs are presented for delivering the output of a laser to a microscopic specimen. The criteria for choosing an approach are presented. The commercial sources for the parts needed to build a photolysis system are also provided. This unit will be particularly useful for investigators interested in single-photon photolysis of caged neurotransmitters in brain slices.


  • photolysis;
  • single-photon photolysis;
  • laser photolysis;
  • caged glutamate