title: Chemical two-photon uncaging: a novel approach to mapping glutamate receptors.
abstract: Functional mapping of neurotransmitter receptors requires rapid and localized application of transmitter. The usefulness of caged glutamate for this purpose has been limited, because photolysis by unfocused light above and below the target cell limits depth resolution. This problem is eliminated by using a double-caged glutamate that requires absorption of two photons for conversion to active glutamate, resulting in a substantial improvement in spatial resolution over conventional caged glutamate. This method was used to map the distribution of glutamate receptors on hippocampal pyramidal neurons. A higher density of AMPA receptors was found on distal apical dendrites than on basal or primary apical dendrites, suggesting that synaptic efficacy is locally heterogeneous. Such "chemical two-photon uncaging" offers a simple, general, and economical strategy for spatially localized photolysis of caged compounds.
authors.affiliation: Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Pettit
authors.forename: S S
authors.initials: SS
authors.lastname: Wang
authors.forename: K R
authors.initials: KR
authors.lastname: Gee
authors.forename: G J
authors.initials: GJ
authors.lastname: Augustine
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000737:chemistry / Q000494:pharmacology; D006624:Hippocampus / Q000737:chemistry* / Q000166:cytology; D008564:Membrane Potentials / Q000187:drug effects; D008856:Microscopy, Fluorescence / Q000379:methods*; D010777:Photochemistry / Q000379:methods*; D017785:Photons; D017966:Pyramidal Cells / Q000737:chemistry* / Q000502:physiology; D051381:Rats; D017470:Receptors, Glutamate / Q000032:analysis*; D014466:Ultraviolet Rays
chemical_list: D018691:Excitatory Amino Acid Antagonists; D017470:Receptors, Glutamate; D018698:Glutamic Acid; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D015763:2-Amino-5-phosphonovalerate