Maturation of long-term potentiation induction rules in rodent hippocampus: role of GABAergic inhibition.
The induction rules of synaptic plasticity are important for the functional operation of a neural network. We asked whether such synaptic plasticity rules change during development from juvenile to adult animals. Using perforated patch and whole-cell recordings from CA1 pyramidal cells in hippocampal slices, we demonstrate here that the postsynaptic requirements for induction of associative long-term potentiation (LTP) shift gradually. Presynaptic stimulation paired with single postsynaptic action potentials became progressively less effective at inducing LTP with advancing developmental age until, in adult hippocampus, postsynaptic bursts of action potentials were necessary to induce synaptic potentiation. This developmental change might be accounted for by changes in GABA(A) receptor-mediated inhibition known to occur in the hippocampus during this postnatal period, because blocking GABA(A) receptor-mediated inhibition re-established the effectiveness of single postsynaptic action potentials at inducing LTP in adult hippocampus. These data reveal a gradual shift in the induction rules for LTP, explained by a maturational change in GABAergic inhibition, and could have implications for our understanding of the role of inhibition in information processing in the brain.
Meredith
Rhiannon M
RM
University Laboratory of Physiology, Oxford University, Oxford, OX1 3PT, United Kingdom. rhiannon.meredith@physiol.ox.ac.uk
Floyer-Lea
Anna M
AM
Paulsen
Ole
O
D000200:Action Potentials / Q000502:physiology; D000367:Age Factors; D000818:Animals; D005260:Female; D058787:GABA-A Receptor Antagonists; D006624:Hippocampus / Q000378:metabolism / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009415:Nerve Net / Q000187:drug effects / Q000502:physiology; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D058787:GABA-A Receptor Antagonists; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid