Learning‐induced bidirectional enhancement of inhibitory synaptic metaplasticity

• DOI: 10.1113/jp284761
• Publication Date: 2024-04-24T06:14:25Z
• Authors: Sankhanava Kundu; Blesson Paul; Iris Reuevni; Raphael Lamprecht; Edi Barkai
• Keywords: Piriform cortex; Channelrhodopsin

Abstract Training rodents in a particularly difficult olfactory‐discrimination (OD) task results the acquisition of ability to perform well, termed ‘rule learning’. In addition enhanced intrinsic excitability and synaptic excitation piriform cortex pyramidal neurons, rule learning increased inhibition across whole cortical network point where it precisely maintains balance between excitation. The mechanism underlying such precise inhibitory enhancement remains be explored. Here, we use brain slices from transgenic mice (VGAT‐ChR2‐EYFP), enabling optogenetic stimulation single GABAergic neurons recordings unitary events neurons. Quantal analysis revealed that learning‐induced is mediated by quantal size evoked events. Next, examined plasticity induced long‐lasting, intrinsically spike firing post‐synaptic Repetitive depolarizing current pulses depolarized (−70 mV) or hyperpolarized (−90 membrane potentials long‐term depression (LTD) potentiation (LTP) inhibition, respectively. We found profound bidirectional increase induce both LTD, L‐type calcium channels, LTP, R‐type channels after learning. Blocking GABA B receptor reversed effect at −90 mV LTP LTD. suggest greatly enhances modify strength principal directions. Such allows fine‐tuning on each particular neuron, thereby stabilizing while maintaining memory rule. image Key points Olfactory discrimination long‐lasting events, minimal stimulation, size. Surprisingly, metaplasticity repetitive firing, bidirectionally. susceptibility LTD channels. also dependent activation receptors. changes enable