A large pool of releasable vesicles in a cortical glutamatergic synapse Journal Article

Author(s): Hallermann, Stefan; Pawlu, Christian; Jonas, Peter; Heckmann, Manfred
Article Title: A large pool of releasable vesicles in a cortical glutamatergic synapse
Abstract: To probe exocytosis at a cortical glutamatergic synapse, we made capacitance measurements in whole-cell recorded hippocampal mossy fiber terminals. Evaluation of different methods by using a morphology-based equivalent electrical model revealed that quantitative capacitance measurements are possible in this presynaptic structure. Voltage pulses leading to presynaptic Ca2+ inflow evoked large capacitance signals that showed saturation with increasing pulse duration. The mean peak capacitance increase was 100 fF, corresponding to a pool of approximately 1,400 releasable vesicles. Thus hippocampal mossy fiber synapses have a vesicular "maxipool." Large pool size and rapid vesicle recycling may underlie the uniquely large extent of activity-dependent plasticity in this synapse.
Keywords: Animals; Rats; Exocytosis; Electrophysiology; Synaptic Transmission; Models, Neurological; Rats, Wistar; Electric Capacitance; Endocytosis; Mossy Fibers, Hippocampal/physiology; Secretory Vesicles/physiology
Journal Title: PNAS
Volume: 100
Issue 15
ISSN: 1091-6490
Publisher: National Academy of Sciences  
Publication Place: United States
Date Published: 2003-01-01
Start Page: 8975
End Page: 80
DOI: 10.1073/pnas.1432836100
Open access: no