Cholinergic Neuromodulation of Prefrontal Attractor Dynamics Controls Performance in Spatial Working Memory

Area of Science:

• Neuroscience
• Computational Neuroscience
• Cognitive Science

Background:

• Cholinergic stimulation of the nucleus basalis (NB) has shown counterintuitive effects on prefrontal cortex (PFC) function.
• NB stimulation enhances behavioral performance and broadens neural tuning, but the underlying mechanism for improved memory remains unclear.

Purpose of the Study:

• To elucidate the mechanism by which cholinergic neuromodulation enhances spatial working memory.
• To investigate the role of attractor dynamics in mediating the effects of neuromodulation on PFC neural activity and behavior.

Main Methods:

• Utilized a continuous bump attractor model to simulate neural activity under cholinergic modulation.
• Investigated biologically plausible heterogeneous network models with discrete bump attractors.
• Analyzed the impact of parameters like neural excitability, saturation, and network connectivity on memory precision and distractibility.

Main Results:

• Increased neural excitability in attractor models broadens tuning and reduces diffusion, improving task performance by prioritizing memory precision.
• Attractor dynamics explain the differential effects of neuromodulation on distractibility based on distractor proximity.
• In discrete networks, reduced spatial correlations and enhanced excitation improved memory precision.

Conclusions:

• Cholinergic neuromodulation controls spatial working memory by perturbing attractor dynamics in the PFC.
• The findings provide a mechanistic understanding of how acetylcholine influences neural coding and cognitive performance.