Loose-patch recordings of single quanta at individual hippocampal synapses

摘要: Synapses in the central nervous system are typically studied by recording electrical responses from cell body of postsynaptic cell. Because neurons normally connected multiple synaptic contacts, these reflect combined activity many thousands synapses, and it remains unclear to what extent properties individual synapses can be deduced population response1,2,3,4,5. We have therefore developed a method for hippocampal synapses. By capturing an isolated presynaptic bouton inside loose-patch pipette associated patch membrane, we were able detect miniature excitatory currents (‘minis’) arising spontaneous vesicle exocytosis at single site, compare with minis recorded simultaneously body. The average peak conductance synapse was about 900 pS, corresponding roughly opening 90 AMPA-type glutamate-receptor channels. variability this 30%, matching value reported neuromuscular junction6. Given that our displayed densities (PSDs), is larger than would predicted random receptor channels, suggesting they not saturated content vesicle. Therefore response quantum neurotransmitter limited number available receptors.