The Mechanism of NMDA Receptor Mediated Increased in Gamma Oscillation Frequency

Activation of N-methyl-D-aspartate (NMDA) receptors has been shown to increase the frequency of gamma oscillations in the CA3 region of the hippocampus. The underlying mechanism of the increase however, is unclear. This project utilizes an integrate-and-fire model of the CA3, based on experimental data, to investigate the increase in oscillation frequency. The model was built first without NMDA receptors to simulate carbachol induced oscillations in vitro. Then, NMDA receptors were added to evoke the increase in oscillation frequency. The model shows that a shift in mechanism, from a pyramidal neuron-interneuron feedback loop, to interneuron-interneuron oscillations, is responsible for the increase in gamma oscillation frequency. An interesting relationship between the active NMDA mediated current and instantaneous cycle frequencies points to further areas of study

A guide to the BRAIN Initiative Cell Census Network data ecosystem

Characterizing cellular diversity at different levels of biological organization and across data modalities is a prerequisite to understanding the function of cell types in the brain. Classification of neurons is also essential to manipulate cell types in controlled ways and to understand their variation and vulnerability in brain disorders. The BRAIN Initiative Cell Census Network (BICCN) is an integrated network of data-generating centers, data archives, and data standards developers, with the goal of systematic multimodal brain cell type profiling and characterization. Emphasis of the BICCN is on the whole mouse brain with demonstration of prototype feasibility for human and nonhuman primate (NHP) brains. Here, we provide a guide to the cellular and spatial approaches employed by the BICCN, and to accessing and using these data and extensive resources, including the BRAIN Cell Data Center (BCDC), which serves to manage and integrate data across the ecosystem. We illustrate the power of the BICCN data ecosystem through vignettes highlighting several BICCN analysis and visualization tools. Finally, we present emerging standards that have been developed or adopted toward Findable, Accessible, Interoperable, and Reusable (FAIR) neuroscience. The combined BICCN ecosystem provides a comprehensive resource for the exploration and analysis of cell types in the brain