Distribution of functional glutamate and GABA receptors on hippocampal pyramidal cells and interneurons.
The distribution of functional neurotransmitter receptors is an important determinant of neuronal information processing. To map the location of functional glutamate and GABA receptors on individual hippocampal neurons, we photolyzed "caged" glutamate and GABA while measuring the electrical currents resulting from activation of these receptors. Responses to uncaged neurotransmitters were spatially nonuniform and varied according to the type of receptor and type of neuron. Every region of CA1 pyramidal cells responded to glutamate and GABA, but glutamate and GABA receptors increased in density along the length of their distal dendrites. Similar gradients of glutamate receptors were found in stratum radiatum interneurons, while GABA responses were detectable only in the perisomatic region of these interneurons. These regional variations in receptor distribution indicate the selective targeting of receptors on central neurons and may reflect a mechanism for local regulation of synaptic efficacy.
Pettit
D L
DL
Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Augustine
G J
GJ
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D016764:Cell Polarity / Q000502:physiology; D003712:Dendrites / Q000737:chemistry / Q000502:physiology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005456:Fluorescent Dyes; D018756:GABA Antagonists / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology* / Q000502:physiology; D066298:In Vitro Techniques; D007395:Interneurons / Q000737:chemistry* / Q000502:physiology; D008239:Lysine / Q000031:analogs & derivatives; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D010852:Picrotoxin / Q000494:pharmacology; D017966:Pyramidal Cells / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D051381:Rats; D018079:Receptors, GABA / Q000032:analysis* / Q000502:physiology; D017470:Receptors, Glutamate / Q000032:analysis* / Q000502:physiology; D013569:Synapses / Q000737:chemistry / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D015763:2-Amino-5-phosphonovalerate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018691:Excitatory Amino Acid Antagonists; D005456:Fluorescent Dyes; D018756:GABA Antagonists; D018698:Glutamic Acid; D008239:Lysine; D010852:Picrotoxin; D018079:Receptors, GABA; D017470:Receptors, Glutamate; D005680:gamma-Aminobutyric Acid; C013411:biocytin