Transition between encoding and consolidation/replay dynamics via cholinergic modulation of CAN current: A modeling...

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Hippocampal place cells show sequential activation during waking, reactivated in a compressed manner during sleep.
• A two-stage model proposes waking activity for encoding and sleep replay for consolidation.
• Mechanisms for distinct temporal scales in encoding and consolidation remain unclear.

Purpose of the Study:

• Investigate if cholinergic modulation adjusts hippocampal network dynamics for encoding and consolidation.
• Explore the role of acetylcholine in bridging different temporal scales of neural activity.

Main Methods:

• Computational simulations of hippocampal network dynamics.
• Modeling the effects of cholinergic modulation on calcium-activated non-specific cationic (CAN) current and synaptic transmission.

Main Results:

• Cholinergic modulation of CAN current and synaptic transmission switches network dynamics between encoding and consolidation modes.
• High acetylcholine (active waking) shows slow spike propagation, mimicking place cell firing.
• Low acetylcholine (sleep) shows fast, compressed activity propagation, mimicking memory replay.

Conclusions:

• Cholinergic system regulates hippocampal network dynamics for distinct temporal scales.
• Modulation of CAN current and synaptic conductance by acetylcholine supports memory encoding and consolidation.