Input-specific induction of long-term depression in Ca(2+)-chelated visual cortex neurons.
An input-dependent increase in postsynaptic Ca2+ may play a role in long-term potentiation (LTP) of synaptic transmission while no or subthreshold increase in Ca2+ is associated with long-term depression (LTD) in the developing visual cortex. To see whether LTD is induced only at tetanized synapses, a Ca(2+)-chelator was injected into layer 2/3 neurons in cortical slices from young rats, and excitatory postsynaptic potentials (EPSPs) of these cells, after test stimulation of the white matter and layer 1/2, were observed before and after tetanic stimulation of the former site. The chelator injection led to LTD of EPSPs at tetanized synapses, but no changes were seen at non-tetanized synapses. These results suggest that tetanic inputs induce LTD at tetanized synapses when they are associated with no or subtle increase in postsynaptic Ca2+.
Yoshimura
Y
Y
Department of Neurophysiology, Osaka University Medical School, Japan.
Tsumoto
T
T
Nishigori
A
A
D000818:Animals; D002118:Calcium / Q000502:physiology*; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013569:Synapses / Q000187:drug effects / Q000502:physiology; D014793:Visual Cortex / Q000187:drug effects / Q000502:physiology*
D004533:Egtazic Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium