Thyroid hormones directly regulate brain activity and help animals adapt to their environment | Science and Technology News |

Abnormal secretion of thyroxine can make people uncomfortable; too much can lead to hand tremors, weight loss, insomnia, irritability, etc.; As thyroxine is an important hormone that regulates metabolism, it is also known to affect hypothalamic neurons and affect body temperature and appetite. Recently, Harvard Medical School found that thyroxine “directly” affects the gene expression of nerve cells and changes the transmission of nerve signals, causing male mice to show more exploratory behavior. The paper was published in“cell”.

To adapt to environmental changes, animals must change their metabolism and behavior patterns. For example, a brown bear going into sleep must not only lower its metabolism and body temperature, but also suppress the desire to drink and eat. During the wet season when resources are abundant, the metabolism of Madagascar gray mouse lemurs increases and their exploratory behavior increases. Since the lemurs’ thyroxine levels increase significantly during the rainy season, this may be the key to environmental flexibility.

To clarify how thyroxine affects the brain, scientists supplemented experimental mice with thyroid hormone and analyzed genetic and behavioral changes in the prefrontal cortex of the brain. The results showed that the expression levels of genes known as thyroxine (such as Hr, Ier5, Cyp11a1) increased as the dose increased, and the genes showed significant changes within an hour of after administration, confirming that thyroxine can “directly” act. Cortex-specific gene expression.

Provides new directions for the treatment of neurodegenerative diseases

After 3.5 days of additional thyroxine supplementation, the time male mice spent in the light field increased significantly, and the trend became more pronounced as the dose increased. Mice are usually disturbed by bright areas and spend most of their time hiding in dark affected areas, The results showed that there was no effect of thyroxine on peripheral tissues. -only enough to change the exploratory behavior of mice.

The team also used “Single-nucleus RNA-sequencing” to analyze the effects of thyroxine on different types of cells in the mouse brain. Thyroxine will significantly increase the expression of genes related to the formation and maintenance of neural connections in astrocytes; oligodendrocytes and precursor cells are stimulated to activate genes associated with differentiation and structural remodeling. Thyroxine in some nerve cells can stimulate a lot of Robo3 protein expression and promote neural network remodeling. All of the above helps to explain how thyroxine affects brain cells to regulate exploratory behavior, and may lead to new directions for the treatment of neurodegenerative diseases.

In summary, thyroxine not only regulates metabolic status and affects animal behavior, but also directly affects cerebral cortex gene expression and neural network remodeling, changing patterns mouse search. These findings extend knowledge of the physiological effects of thyroxine, which has a direct effect on the brain. These findings will help explain how thyroid dysfunction affects people’s behavior and emotions, and provide new research and treatment directions for related neuropsychological disorders.

(Source of first image:Photo by Freepik)

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