[1] INSERM,
[2] Unit 495,undefined
[3] Biologie des Interactions Neurones-Glie,undefined
[4] Salpetriere Hospital,undefined
[5] 47 Bd de l'Hôpital,undefined
[6] 75651 Paris cedex 13,undefined
[7] France,undefined
[8] e-mail: baumann@ccr.jussieu.fr,undefined
[9] Tel.: 33-1-42162150,undefined
[10] Fax: 33-1-45848008,undefined