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Titolo:
A COMPARISON OF SPONTANEOUS EPSCS IN LAYER-II AND LAYER-IV-V NEURONS OF THE RAT ENTORHINAL CORTEX IN-VITRO
Autore:
BERRETTA N; JONES RSG;
Indirizzi:
UNIV OXFORD,DEPT PHARMACOL,MANSFIELD RD OXFORD OX1 3QT ENGLAND
Titolo Testata:
Journal of neurophysiology
fascicolo: 2, volume: 76, anno: 1996,
pagine: 1089 - 1100
SICI:
0022-3077(1996)76:2<1089:ACOSEI>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
TEMPORAL-LOBE EPILEPSY; AMINO-ACID RECEPTORS; EXCITATORY POSTSYNAPTIC CURRENTS; CA3 PYRAMIDAL NEURONS; ASPINY HILAR NEURONS; HIPPOCAMPAL SLICES; GLUTAMATE RECEPTORS; SYNAPTIC CURRENTS; CORTICAL-CELLS; PATCH-CLAMP;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
46
Recensione:
Indirizzi per estratti:
Citazione:
N. Berretta e R.S.G. Jones, "A COMPARISON OF SPONTANEOUS EPSCS IN LAYER-II AND LAYER-IV-V NEURONS OF THE RAT ENTORHINAL CORTEX IN-VITRO", Journal of neurophysiology, 76(2), 1996, pp. 1089-1100

Abstract

1. We have compared the characteristics of spontaneous excitatory postsynaptic currents (sEPSCs) in neurons of layer IV-V and layer II of the rat entorhinal cortex (EC) using whole cell voltage-clamp recordings in a slice preparation.2. The frequency of sEPSCs was similar in thetwo layers, but the events in layer IV-V had a larger mean amplitude,faster rise time, and were faster to decay. The difference in amplitude could be attributed to the presence of a population of larger events in the layer IV-V neurons that were not present in layer II. 3. Electrotonic length was greater in layer II neurons, suggesting that the difference in kinetics of the sEPSCs may be explained partly by electrotonic attenuation. 4. The frequency of sEPSCs in both layers was reduced by tetrodotoxin (TTX) to a similar extent (15-20%). However, the amplitude distribution was unchanged in layer II, whereas in layer IV-V TTX abolished most of the larger amplitude sEPSCs. 5. 6-cyano-7-nitroquinoxaline-2,3-dione or 6-nitro-7-sulphamoylbenzo (f)-quinoxaline-2,3-dione, abolished most of the sEPSCs in neurons of both layers. However, even at negative holding potentials, a population of slower time-course sEPSCs remained in the presence of these antagonists. 6. The slow sEPSCs were more frequent in layer IV-V but had similar characteristics in both layers, being increased in amplitude at more positive holding potentials or in Mg2+-free medium, and blocked by 2-amino-5-phosphonovalerate (AP5). 7. AP5 alone (i.e., without addition of lpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid antagonists) reduced the peak amplitude and decay phase of sEPSCs in layer IV-V neurons but appeared to have little effect on amplitude and only a weak effect on decayphase in layer II. 8. Thus both layer IV-V and layer II neurons of the EC suffer continuous spontaneous excitation. However, layer IV-V neurons exhibit larger amplitude sEPSCs, probably mediated by release of multiple quanta of neurotransmitter. In addition, although both types of neurons display spontaneous excitation mediated by N-methyl-D-aspartate receptors, this component appears more pronounced in the deeper layers.

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Documento generato il 07/07/20 alle ore 12:51:42