Brain complexity: gene response to light stimuli (Introduction)

by David Turell , Thursday, February 08, 2018, 19:34 (2262 days ago) @ David Turell

Work in mouse cortex demonstrates many genetic changes as the brain modifies to new stimuli:

https://medicalxpress.com/news/2018-02-single-cell-analysis-reveals-diverse-landscape.html

"Using novel technologies developed at HMS, the team looked at how a single sensory experience affects gene expression in the brain by analyzing more than 114,000 individual cells in the mouse visual cortex before and after exposure to light.

"Their findings revealed a dramatic and diverse landscape of gene expression changes across all cell types, involving 611 different genes, many linked to neural connectivity and the brain's ability to rewire itself to learn and adapt.

"The results offer insights into how bursts of neuronal activity that last only milliseconds trigger lasting changes in the brain, and open new fields of exploration for efforts to understand how the brain works.

"'What we found is, in a sense, amazing. In response to visual stimulation, virtually every cell in the visual cortex is responding in a different way," said co-senior author Michael Greenberg, the Nathan Marsh Pusey Professor of Neurobiology and chair of the Department of Neurobiology at HMS.

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"The team found significant changes in gene expression after light exposure in all cell types in the visual cortex—both neurons and, unexpectedly, nonneuronal cells such as astrocytes, macrophages and muscle cells that line blood vessels in the brain.

Roughly 50 to 70 percent of excitatory neurons, for example, exhibited changes regardless of their location or function. Remarkably, the authors said, a large proportion of non-neuronal cells—almost half of all astrocytes, for example—also exhibited changes.

"The team identified thousands of genes with altered expression patterns after light exposure, and 611 genes that had at least two-fold increases or decreases.

"Many of these genes have been previously linked to structural remodeling in the brain, suggesting that virtually the entire visual cortex, including the vasculature and muscle cell types, may undergo genetically controlled rewiring in response to a sensory experience.

"There has been some controversy among neuroscientists over whether gene expression could functionally control plasticity or connectivity between neurons.

"'I think our study strongly suggests that this is the case, and that each cell has a unique genetic program that's tailored to the function of a given cell within a neural circuit," Greenberg said.

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"'Experience and environmental stimuli appear to almost constantly affect gene expression and function throughout the brain. This may help us to understand how processes such as learning and memory formation, which require long-term changes in the brain, arise from the short bursts of electrical activity through which neurons signal to each other," Greenberg said.

"One especially interesting area of inquiry, according to Greenberg, includes the regulatory elements that control the expression of genes in response to sensory experience. In a paper published earlier this year in Molecular Cell, he and his team explored the activity of the FOS/JUN protein complex, which is expressed across many different cell types in the brain but appears to regulate unique programs in each different cell type."

Comment: This demonstrated plasticity shows how intimately the brain modifies itself to the immaterial tasks at hand. The brain and the s/s/c are very intimately connected, even if one is material and one is immaterial. Yet from the NDE reports the s/s/c can exist and record experiences while not in the presence of a functional brain. Clearly dualism.