I. Address, I. Khalilov-ben-ari, and . U29, and to apply drugs selectively Biology of RAN, 2-31, Lobachevski str., Kazan, Russia. to the commissural connections Address for reprint requests The three-compartment chamber offers a wide range of 123 Bd de Port-Royal, Paris 75014, France. possibilities and considerably extends the advantages offered Received 29 by in vitro preparations notably to study: 1) the generation and commissural propagation of synchronized neuronal net-REFERENCES work activities, 2) the maturation of functional commissural CAZALETS, final form 21 The synaptic drive from the connections and the characterization of the receptors inspinal locomotor network to motoneurons in the newborn rat, 1997.

K. , I. Esclapez, M. Medina, I. Aggoun, D. Lamsa et al., LEINEKUdrug and their distal consequences, and the evaluation of the A novel in vitro preparation: consequences of neuronal hyperactivity independently from the intact hippocampal formation, Neuron, vol.19, pp.743-749, 1997.

K. , O. And, O. Kiehn, X. Leinekugel, I. Khalilov et al., Crossed rhythmic synaptic input to motoneuuseful to study the propagation of the epileptiform activites rons during selective activation of the contralateral spinal locomotor network and formation of the epileptogenic mirror focus Giant depolarizing potentials: the septal pole of the hippocampus paces the activity of the developing intact septo-hippocampal complex in vitro, J. Neurosci. J. Neurosci, vol.17, pp.9433-9447, 1997.

. H. We-thank-dr, Gozlan for help in spectrophotometry study and J.-P