Distribution of spontaneous currents along the somato-dendritic axis of rat hippocampal CA1 pyramidal neurons. - Inserm - Institut national de la santé et de la recherche médicale Accéder directement au contenu
Article Dans Une Revue Neuroscience Année : 2000

Distribution of spontaneous currents along the somato-dendritic axis of rat hippocampal CA1 pyramidal neurons.

Résumé

Excitatory and inhibitory pathways have specific patterns of innervation along the somato-dendritic axis of neurons. We have investigated whether this morphological diversity was associated with variations in the frequencies of spontaneous and miniature GABAergic and glutamatergic synaptic currents along the somato-dendritic axis of rat hippocampal CA1 pyramidal neurons. Using in vitro whole cell recordings from somata, apical dendrites and basal dendrites (for which we provide the first recordings) of CA1 pyramidal neurons, we report that over 90% of the spontaneous currents were GABAergic, <10% being glutamatergic. The frequency of spontaneous GABAergic currents was comparable in the soma and in the dendrites. In both somata and dendrites, the Na(+) channel blocker tetrodotoxin abolished more than 80% of the spontaneous glutamatergic currents. In contrast, tetrodotoxin abolished most dendritic (>90%) but not somatic (<40%) spontaneous GABAergic currents. Computer simulations suggest that in our experimental conditions, events below 40pA are electrotonically filtered to such a degree that they are lost in the recording noise. We conclude that, in vitro, inhibition is massively predominant over excitation and quantitatively evenly distributed throughout the cell. However, inhibition appears to be mainly activity-dependent in the dendrites whereas it can occur in the absence of interneuron firing in the soma. These results can be used as a benchmark to compare values obtained in pathological tissue, such as epilepsies, where changes in the balance between excitation and inhibition would dramatically alter cell behaviour.
Fichier sous embargo
Fichier sous embargo
Date de visibilité indéterminée
Loading...

Dates et versions

inserm-00484937 , version 1 (19-05-2010)

Identifiants

  • HAL Id : inserm-00484937 , version 1
  • PUBMED : 10974423

Citer

Rosa Cossart, June C. Hirsch, Robert C. Cannon, Céline Dinoncourt, Howard V. Wheal, et al.. Distribution of spontaneous currents along the somato-dendritic axis of rat hippocampal CA1 pyramidal neurons.. Neuroscience, 2000, 99 (4), pp.593-603. ⟨inserm-00484937⟩

Collections

INSERM UNIV-AMU
61 Consultations
1 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More