Working Principles of Associative Memory Cells

Abstract

Compared with neurons, associative memory cells receive synapse innervations that bring the associated signals during learning activities and are recruited from neurons during their coactivation within intramodal cortices and among cross-modal cortices. Synapse innervations among associative memory cells as well as their characters constitute working principles of associative memory cells. The connection patterns among associative memory cells determine the direction of their information flow and the specificity of the memory contents. The weight of synapse innervations for individual associative memory cells influences their functional states to be activated during further recruitments and memory retrieval. The interactions among glutamatergic and GABAergic associative memory cells influence homeostasis in their local network for memory contrast and over-excitation prevention. As the family of neurons, associative memory cells possess neuronal excitability that is set by threshold potentials and influences the spiking capability. The excitability of associative memory cells mainly influences whether they are activated driven by excitatory synapses from the innate inputs, the coactivated neurons, and the arousal system, as well as how spike patterns have been produced for encoding memory contents and triggering memory retrieval strength. Recruitment-relevant and activity-induced refinements of associative memory cells in their synapse innervations and excitability influence their functional states to encode the integrative storage and reciprocal retrieval of associated signals. With these characters and working principles of associative memory cells, memory traces that include primary associative memory cells in sensory cortices, secondary associative memory cells in association cortices, and cognition-relevant brain areas as well as memory output cells in the motor cortex work for the brain functions in relevance to memories in the aspects of physiology and psychology.