The Role of Dynamic Columns in Explaining Gamma-band Synchronization and NMDA Receptors in Cognitive Functions

Abstract

The role of gamma-band synchronization and NMDA receptors in cognitive functions and neuropsychiatric disorders has received increased attention over the past two decades, with significant controversy about their roles. The role of the cortical column as a basic unit in cortical processing has also been debated. The current paper presents the theoretical argument that the dynamically formed column is the binary unit (bit) involved in all cortical processing and memory, and that gamma-band synchronization is required for columnar formation. Moreover, the role of NMDA receptors is explained as allowing the consolidation of synchronized boundary minicolumns that serve as the bit, as well as strengthening the connections among the circuit of columns that are involved with any given memory. Following a discussion of the microcircuitry that may be involved, there is a brief discussion on how the serious neuropsychiatric disorders of schizophrenia, autism, and Alzheimer’s disease can be conceptualized as disorders of disrupted column formation. The arguments presented provide a theoretical basis for future research to determine the validity of this novel view.

Keywords

• cortical column
• gamma oscillations
• synchronization
• NMDA receptors
• cognitive functions
• memory
• schizophrenia
• autism
• Alzheimer's disease