An ongoing subthreshold neuronal state established through dynamic coassembling of cortical cells.

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Neuronal ensemble activation, whether spontaneous or triggered, can involve a shared population of neurons called core cells.
• The precise role and significance of these core cells in dictating local network dynamics and information processing remain largely unexplored.

Purpose of the Study:

• To investigate the function of core cells in neuronal ensemble activation and their role in sensory information processing using a computational model.
• To elucidate the mechanism by which core cells influence the behavior of noncore cells within a neural network.

Main Methods:

• Simulated a neural network model of an early sensory cortical area.
• Differentiated between core cells (unselective responsiveness) and noncore cells (selective responsiveness).
• Analyzed neuronal ensemble activation patterns during spontaneous and stimulus-triggered activity, focusing on dynamic coassembling between core and noncore cell assemblies.

Main Results:

• Core cells were consistently active in all ensemble activations, recruiting varying sets of noncore cells.
• Ensemble activation occurred via dynamic coassembling, where core and noncore cell assemblies transiently or persistently linked.
• Transient coassembling during spontaneous activity sub-threshold depolarized noncore cells, enabling rapid responses to stimulation.
• Persistent coassembling during triggered activity further enhanced noncore cell responsiveness.

Conclusions:

• Core cells act as a central nucleus, regulating noncore cell activity and network dynamics.
• Dynamic coassembling, involving transient and persistent phases, is a crucial mechanism for cortical preparation and response to sensory input.
• This mechanism highlights the importance of core cells in integrating sensory information and modulating neural responses.