Precisely localized LTD in the neocortex revealed by infrared-guided laser stimulation.
In a direct approach to elucidate the origin of long-term depression (LTD), glutamate was applied onto dendrites of neurons in rat neocortical slices. An infrared-guided laser stimulation was used to release glutamate from caged glutamate in the focal spot of an ultraviolet laser. A burst of light flashes caused an LTD-like depression of glutamate receptor responses, which was highly confined to the region of "tetanic" stimulation (<10 micrometers). A similar depression of glutamate receptor responses was observed during LTD of synaptic transmission. A spatially highly specific postsynaptic mechanism can account for the LTD induced by glutamate release.
Dodt
H
H
Max-Planck-Institute of Psychiatry, Kraepelinstrasse 2, 80804 Munich, Germany. dodt@mpipsykl.mpg.de
Eder
M
M
Frick
A
A
Zieglgänsberger
W
W
D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid / Q000378:metabolism; D066298:In Vitro Techniques; D007259:Infrared Rays; D007834:Lasers; D018715:Microscopy, Video; D019579:Neocortex / Q000166:cytology / Q000502:physiology*; D009473:Neuronal Plasticity; D018408:Patch-Clamp Techniques; D010782:Photolysis; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017470:Receptors, Glutamate / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000378:metabolism; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission
C102508:(carboxy-2-nitrobenzyl)glutamic acid; D018691:Excitatory Amino Acid Antagonists; D005971:Glutamates; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D016291:Dizocilpine Maleate