Skip to Main content Skip to Navigation
Journal articles

Neuronal migration disorders: heterotopic neocortical neurons in CA1 provide a bridge between the hippocampus and the neocortex.

Abstract : Neuronal migration disorders have been involved in various pathologies, including epilepsy, but the properties of the neural networks underlying disorders have not been determined. In the present study, patch clamp recordings were made from intrahippocampal heterotopic as well as from neocortical and hippocampal neurons from brain slices of rats with prenatally methylazoxymethanol-induced cortical malformation. We report that heterotopic neurons have morphometrical parameters and cellular properties of neocortical supragranular neurons and are integrated in both neocortical and hippocampal networks. Thus, stimulation of the white matter induces both antidromic and orthodromic response in heterotopic and neocortical neurons. Stimulation of hippocampal afferents evokes a monosynaptic response in the majority of heterotopic neurons and a polysynaptic all-or-none epileptiform burst in the presence of bicuculline to block gamma-aminobutyric acid type A inhibition. Furthermore, hippocampal paroxysmal activity generated by bath application of bicuculline can spread directly to the neocortex via the heterotopia in methylazoxymethanol-treated but not in naive rats. We conclude that heterotopias form a functional bridge between the limbic system and the neocortex, providing a substrate for pathological conditions.
Document type :
Journal articles
Complete list of metadatas

Cited literature [22 references]  Display  Hide  Download

https://www.hal.inserm.fr/inserm-00522445
Contributor : Roman Tyzio <>
Submitted on : Thursday, September 30, 2010 - 4:26:41 PM
Last modification on : Monday, November 9, 2020 - 10:10:06 AM
Long-term archiving on: : Friday, December 2, 2016 - 12:57:23 PM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : jamais

Please log in to resquest access to the document

Identifiers

  • HAL Id : inserm-00522445, version 1
  • PUBMED : 9707635

Collections

Citation

Nicolas Chevassus-Au-Louis, Patrice Congar, Alfonso Represa, Yezekiel Ben-Ari, Jean-Luc Gaïarsa. Neuronal migration disorders: heterotopic neocortical neurons in CA1 provide a bridge between the hippocampus and the neocortex.. Proceedings of the National Academy of Sciences of the United States of America , National Academy of Sciences, 1998, 95 (17), pp.10263-8. ⟨inserm-00522445⟩

Share

Metrics