The Journal of Neuroscience, May 1, 2000, 20(9):3233-3243
Selective Presynaptic Propagation of Long-Term Potentiation in
Defined Neural Networks
Hui-zhong W.
Tao,
Li I.
Zhang,
Guo-qiang
Bi, and
Mu-ming
Poo
Department of Biology, University of California at San Diego, La
Jolla, California 92093-0357
Induction of long-term potentiation (LTP) of the synaptic
connection between two hippocampal glutamatergic neurons in a neural network formed in cell culture resulted in a specific pattern of
potentiation at other connections within the network. We found that
potentiation propagated from the site of induction retrogradely to
glutamatergic or GABAergic synapses received by the dendrites of the
presynaptic neuron and laterally to those made by its axonal collaterals onto other glutamatergic cells. In contrast, synapses made
by the same presynaptic neuron onto GABAergic cells were not affected,
and there was no postsynaptic lateral or forward propagation to other
synapses received or made by the postsynaptic neuron. In addition,
there was no secondary propagation to synapses not directly associated
with the presynaptic neuron. Both induction and propagation of LTP
required correlated spiking of the postsynaptic cell as well as the
activation of the NMDA subtype of glutamate receptors. Such selective
propagation suggests the existence of a long-range cytoplasmic
signaling within the presynaptic neuron, leading to a specific pattern
of coordinated potentiation along excitatory pathways in a neural network.
Key words:
synaptic plasticity; LTP; hippocampal culture; correlated
activity; spike timing; Hebbian; synapse specificity
Copyright © 2000 Society for Neuroscience 0270-6474/00/2093233-11$05.00/0
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