Activity- and age-dependent GABAergic synaptic plasticity in the developing rat hippocampus.
Activity-dependent plasticity of GABAergic synaptic transmission was investigated in rat hippocampal slices obtained between postnatal day (P) 0-15 using the whole-cell patch-clamp recording technique. Spontaneous GABA(A) receptor-mediated postsynaptic currents (sGABA(A)-PSCs) were isolated in the presence of ionotropic glutamate receptor antagonists. A conditioning protocol relevant to the physiological condition, consisting of repetitive depolarizing pulses (DPs) at 0.1 Hz, was able to induce long-lasting changes in both frequency and amplitude of sGABA(A)-PSCs between P0 and P8. Starting from P12, DPs were unable to induce any form of synaptic plasticity. The effects of DPs were tightly keyed to the frequency at which they were delivered. When delivered at a lower (0.05 Hz) or higher (1 Hz) frequency, DPs failed to induce any long-lasting change in the frequency or amplitude of sGABA(A)-PSCs. In two cases, DPs were able to activate sGABA(A)-PSCs in previously synaptically silent cells at P0-1. These results show that long-term changes in GABAergic synaptic activity can be induced during a restricted period of development by a conditioning protocol relevant to the physiological condition. It is suggested that such activity-induced modifications may represent a physiological mechanism for the functional maturation of GABAergic synaptic transmission.
Gubellini
P
P
Institut de Neurobiologie de la Mediterranée (INMED), Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 29, Avenue de Luminy, BP 13, 13273 Marseille Cedex 09, France.
Ben-Ari
Y
Y
Gaïarsa
J L
JL
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009924:Organ Culture Techniques; D017966:Pyramidal Cells / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000187:drug effects / Q000378:metabolism*; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018691:Excitatory Amino Acid Antagonists; D005680:gamma-Aminobutyric Acid