Fully-primed slowly-recovering vesicles mediate presynaptic LTP at neocortical neurons

• DOI: 10.1073/pnas.2305460120
• Publication Date: 2023-10-19T17:43:25Z
• Authors: Iron Weichard; Holger Taschenberger; Felix Gsell; Grit Bornschein; Andreas Ritzau-Jost; Hartmut Schmidt; Robert J. Kittel; Jens Eilers; Erwin Neher; Stefan Hallermann; Jana Nerlich
• Keywords: Neuronal memory allocation; Nonsynaptic plasticity

Pre- and postsynaptic forms of long-term potentiation (LTP) are candidate synaptic mechanisms underlying learning memory. At layer 5 pyramidal neurons, LTP increases the initial strength but also short-term depression during high-frequency transmission. This classical form presynaptic has been referred to as redistribution efficacy. However, remain unclear. We therefore performed whole-cell recordings from neurons in acute cortical slices rats analyzed function before after induction by paired pre- neuronal activity. was successfully induced about half connections tested resulted increased transmission a decelerated recovery due an fraction slow component. Analysis with recently established sequential two-step vesicle priming model indicates increase abundance fully-primed slowly-recovering vesicles. A systematic analysis plasticity synapse-to-synapse variability at various types synapses revealed that stronger generally recover more slowly depression. Finally, pharmacological stimulation cyclic adenosine monophosphate diacylglycerol signaling pathways, which both known promote priming, mimicked slowed Our data thus demonstrate primarily enlarging subpool