HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 556/1/147    most recent jphysiol.2003.053306v1 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Granseth, B. Articles by Lindström, S. Search for Related Content PubMed PubMed Citation Articles by Granseth, B. Articles by Lindström, S.

Department of Biomedicine and Surgery, Faculty of Health Sciences, Linköping University, SE-581 85 Linköping, Sweden

Augmentation is a component of short-term synaptic plasticity with a gradual onset and duration in seconds. To investigate this component at the corticogeniculate synapse, whole cell patch-clamp recordings were obtained from principal cells in a slice preparation of the rat dorsal lateral geniculate nucleus. Trains with 10 stimuli at 25 Hz evoked excitatory postsynaptic currents (EPSCs) that grew in amplitude, primarily from facilitation. Such trains also induced augmentation that decayed exponentially with a time constant = 4.6 ± 2.6 s (mean ± standard deviation). When the trains were repeated at 1–10 s intervals, augmentation markedly increased the size of the first EPSCs, leaving late EPSCs unaffected. The magnitude of augmentation was dependent on the number of pulses, pulse rate and intervals between trains. Augmented EPSCs changed proportionally to basal EPSC amplitudes following alterations in extracellular calcium ion concentration. The results indicate that augmentation is determined by residual calcium remaining in the presynaptic terminal after repetitive spikes, competing with fast facilitation. We propose that augmentation serves to maintain a high synaptic strength in the corticogeniculate positive feedback system during attentive visual exploration.

(Received 12 August 2003; accepted after revision 14 January 2004; first published online 14 January 2004)
Correspondence address B. Granseth: MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.  Email: bjogr{at}mrc-lmb.cam.ac.uk

This article has been cited by other articles:

				D. J. Uhlrich, K. A. Manning, M. L. O'Laughlin, and W. W. Lytton Photic-Induced Sensitization: Acquisition of an Augmenting Spike-Wave Response in the Adult Rat Through Repeated Strobe Exposure J Neurophysiol, December 1, 2005; 94(6): 3925 - 3937. [Abstract] [Full Text] [PDF]

				P. Wasling, E. Hanse, and B. Gustafsson Developmental Changes in Release Properties of the CA3-CA1 Glutamate Synapse in Rat Hippocampus J Neurophysiol, November 1, 2004; 92(5): 2714 - 2724. [Abstract] [Full Text] [PDF]