Nitric oxide acts directly in the presynaptic neuron to produce long-term potentiation in cultured hippocampal neurons.
Nitric oxide (NO) has been proposed to act as a retrograde messenger during long-term potentiation (LTP) in the CA1 region of hippocampus, but the inaccessibility of the presynaptic terminal has prevented a definitive test of this hypothesis. Because both sides of the synapse are accessible in cultured hippocampal neurons, we have used this preparation to investigate the role of NO. We examined LTP following intra- or extracellular application of an NO scavenger, an inhibitor of NO synthase, and a membrane-impermeant NO donor that releases NO only upon photolysis with UV light. Our results indicate that NO is produced in the postsynaptic neuron, travels through the extracellular space, and acts directly in the presynaptic neuron to produce long-term potentiation, supporting the hypothesis that NO acts as a retrograde messenger during LTP.
Arancio
O
O
Center for Neurobiology and Behavior, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
Kiebler
M
M
Lee
C J
CJ
Lev-Ram
V
V
Tsien
R Y
RY
Kandel
E R
ER
Hawkins
R D
RD
D000818:Animals; D002478:Cells, Cultured / Q000201:enzymology; D005110:Extracellular Space / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000166:cytology* / Q000502:physiology; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008706:Methemoglobin / Q000494:pharmacology; D008845:Microinjections; D009211:Myoglobin / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D018377:Neurotransmitter Agents / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis / Q000378:metabolism / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010782:Photolysis; D017729:Presynaptic Terminals / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013744:Tetanus Toxin / Q000494:pharmacology; D014466:Ultraviolet Rays
D009211:Myoglobin; D018377:Neurotransmitter Agents; D013744:Tetanus Toxin; C017595:oxymyoglobin; D009569:Nitric Oxide; D008706:Methemoglobin; D019001:Nitric Oxide Synthase