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Titolo:
Kindling induces transient fast inhibition in the dentate gyrus-CA3 projection
Autore:
Gutierrez, R; Heinemann, U;
Indirizzi:
Inst Politecn Nacl, CINVESTAV, Dept Fisiol Biofis & Neurociencias, Mexico City 07000, DF, Mexico Inst Politecn Nacl Mexico City DF Mexico 07000 ico City 07000, DF, Mexico Humboldt Univ, Johannes Muller Inst Physiol, D-10117 Berlin, Germany Humboldt Univ Berlin Germany D-10117 st Physiol, D-10117 Berlin, Germany
Titolo Testata:
EUROPEAN JOURNAL OF NEUROSCIENCE
fascicolo: 7, volume: 13, anno: 2001,
pagine: 1371 - 1379
SICI:
0953-816X(200104)13:7<1371:KITFII>2.0.ZU;2-0
Fonte:
ISI
Lingua:
ENG
Soggetto:
INTRAHIPPOCAMPAL TETANUS TOXIN; GLUTAMIC-ACID DECARBOXYLASE; RAT ENTORHINAL CORTEX; HIPPOCAMPUS IN-VITRO; GRANULE CELLS; EPILEPTIFORM ACTIVITY; MESSENGER-RNA; SYNAPTIC REORGANIZATION; EXPERIMENTAL EPILEPSY; INCREASED EXPRESSION;
Keywords:
epilepsy; hippocampus; mossy fibres; rat; synaptic plasticity;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
62
Recensione:
Indirizzi per estratti:
Indirizzo: Gutierrez, R Inst Politecn Nacl, CINVESTAV, Dept Fisiol Biofis & Neurociencias, Apartado Postal 14-740, Mexico City 07000, DF, Mexico Inst Politecn Nacl Apartado Postal 14-740 Mexico City DF Mexico 07000
Citazione:
R. Gutierrez e U. Heinemann, "Kindling induces transient fast inhibition in the dentate gyrus-CA3 projection", EUR J NEURO, 13(7), 2001, pp. 1371-1379

Abstract

The granule cells of the dentate gyrus (DG) send a strong glutamatergic projection, the mossy fibre tract, toward the hippocampal CA3 field, where itexcites pyramidal cells and neighbouring inhibitory interneurons. Despite their excitatory nature, granule cells contain small amounts of GAD (glutamate decarboxylase), the main synthetic enzyme for the inhibitory transmitter GABA. Chronic temporal lobe epilepsy results in transient upregulation ofGAD and GABA in granule cells, giving rise to the speculation that following overexcitation, mossy fibres exert an inhibitory effect by release of GABA. We therefore stimulated the DG and recorded synaptic potentials from CA3 pyramidal cells in brain slices from kindled and control rats. In both preparations, DG stimulation caused excitatory postsynaptic potential (EPSP)/inhibitory postsynaptic potential (IPSP) sequences. These potentials could be completely blocked by glutamate receptor antagonists in control rats, while in the kindled rats, a bicuculline-sensitive fast IPSP remained, with an onset latency similar to that of the control EPSP. Interestingly, this IPSP disappeared 1 month after the last seizure. When synaptic responses wereevoked by high-frequency stimulation, EPSPs in normal rats readily summateto evoke action potentials. In slices from kindled rats, a summation of IPSPs overrides that of the EPSPs and reduces the probability of evoking action potentials. Our data show for the first time that kindling induces functionally relevant activity-dependent expression of fast inhibition onto pyramidal cells, coming from the DG, that can limit CA3 excitation in a frequency-dependent manner.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/04/20 alle ore 22:40:01