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This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 586/19/4675    most recent jphysiol.2008.160044v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Perez-Gonzalez, A. P. Articles by Llobet, A. PubMed PubMed Citation Articles by Perez-Gonzalez, A. P. Articles by Llobet, A. Related Collections Neuroscience

¹ Laboratori de Neurobiologia – CIBERNED, IDIBELL – Universitat de Barcelona, 08907 L'Hospitalet de Llobregat, Spain

Nicotinic synapses in the autonomous nervous system display use-dependent plasticity but the contribution of cellular environment, as well as the presynaptic mechanisms implicated in this process remain to be determined. To address these questions synaptic function was assayed in rat superior cervical ganglion (SCG) neurons microcultured in isolation from any other cell type and compared to those microcultured in the presence of Schwann cells of ganglionar origin. Schwann cells were not required for synapse formation in vitro because functional cholinergic autaptic synapses were established in both experimental conditions. The number of synapses was comparable between the two culture conditions but the frequency of spontaneous miniature excitatory postsynaptic currents was enhanced in those neurons grown in direct contact with glial cells. Autapses displayed facilitation and depression, both processes being determined by the fraction of vesicles from the readily releasable pool discharged by an action potential. At high release probabilities vesicles were more efficiently mobilized, thus promoting depression, whilst low release probabilities made facilitation likely to occur. Schwann cells did not modify significantly facilitation but increased synaptic depression. In single cell microcultures, paired pulse stimuli showed a monoexponential recovery from depression with a time constant of 60 ms, while in microcultures developed together with glial cells, recovery was bi-exponential with a significantly slower time course. Altogether these results show that Schwann cells from sympathetic ganglia directly modulate use-dependent plasticity of nicotinic synapses in vitro by enhancing short-term depression.

(Received 18 July 2008; accepted after revision 7 August 2008; first published online 14 August 2008)
Corresponding author A. Llobet: Laboratori de Neurobiologia – CIBERNED, IDIBELL – Universitat de Barcelona, 08907 L'Hospitalet de Llobregat, Spain.  Email: allobet{at}ub.edu