Plateau potentials are instructive signals for behavioral timescale synaptic plasticity in the neocortex.

Area of Science:

• Neuroscience
• Synaptic Plasticity
• Learning Mechanisms

Background:

• Synaptic plasticity underlies learning by modifying synaptic weights over various timescales.
• Spike-timing dependent plasticity (STDP) in the neocortex requires numerous precise activity pairings, posing challenges for explaining rapid, single-shot learning.
• Behavioral timescale synaptic plasticity (BTSP), driven by plateau potentials in the hippocampus, facilitates single-trial synaptic weight modification.

Purpose of the Study:

• To investigate the presence and function of plateau potentials in layer 5 pyramidal neurons (L5 PNs) of the mouse primary visual cortex (V1).
• To determine if plateau potentials can induce single-shot changes in sensory representations via BTSP.
• To elucidate the role of plateau potentials in rapid learning and synaptic weight adjustment in the neocortex.

Main Methods:

• Electrophysiological recordings in acute slices of mouse V1.
• Induction and observation of spontaneous and experimentally induced plateau potentials in L5 PNs.
• Assessment of synaptic plasticity and changes in neuronal responses to visual stimuli following plateau potentials.

Main Results:

• Layer 5 PNs in mouse V1 exhibit prevalent plateau potentials.
• Both spontaneous and induced plateau potentials rapidly and persistently altered L5 PN responses to visual stimuli.
• Plateau potentials induced synapse-specific plasticity with minimal repetitions over seconds-long intervals, consistent with BTSP.

Conclusions:

• Plateau potentials are a prevalent mechanism in the neocortex capable of driving rapid, single-shot changes in neuronal representations.
• BTSP, mediated by plateau potentials, provides a mechanism for dynamic adjustment of neocortical synaptic weights, supporting swift learning.
• This finding challenges the STDP-only model and offers a new perspective on learning mechanisms in the brain.