Recurrent activity propagates through labile ensembles in macaque dorsolateral prefrontal microcircuits.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Computational Neuroscience

Background:

• The dorsolateral prefrontal cortex (dlPFC) is crucial for advanced cognitive functions in humans and non-human primates.
• Intracortical synaptic architectures within the dlPFC are considered the neurobiological basis for these cognitive processes.
• The prevailing model views cortical columns as fundamental processing units, forming the
• canonical
• cortical microcircuit.

Purpose of the Study:

• To investigate the neurobiological substrate of cognitive functions within the dlPFC.
• To reconcile competing theories of microcircuit activity coordination by isolating intracortical computations.
• To understand how synaptic architecture constrains cognitive performance.

Main Methods:

• Utilized high-density calcium imaging of macaque dlPFC.
• Interrogated microcircuit networks ex vivo to isolate intracortical computations.
• Employed peri-sulcal stimulation to evoke recurrent activity in deep layers.

Main Results:

• Observed that activity propagates through stochastically assembled intracortical networks.
• Found that orderly, predictable, low-dimensional collective dynamics emerge from ensembles with labile cellular memberships.
• Demonstrated that microcircuit excitability correlates with individual cognitive performance.

Conclusions:

• The generation of high-fidelity population-level signals arises from distributed, labile networks in the dlPFC.
• Findings challenge engram or localist architectures, suggesting a dynamic network basis for cognition.
• Quantifiable constraints imposed by synaptic architecture anchor models of abstract cortical functions.