summary: The regulatory mechanisms of feeding-dependent neural development can be explored at the molecular level using appropriate models, such as Drosophila.
Source: Kyoto University
Nutrition, as an influencing part of the physiological state of an organism, seems to extend to all stages of life. Neuronal development, including the growth of dendrites and axons, is known to be metabolically demanding, but little is known about how specific nutrients affect neuronal development.
A team of researchers at Kyoto University’s School of Biological Studies has found that the regulatory mechanisms of nutrient-dependent neurodevelopment can be explored at the molecular level using appropriate models.
One of these models is Drosophila “C4da—or class IV dendritic arborization—neurons found in fruit fly larvae,” says lead author Yukaku Hattori.
Dendrites of C4da neurons—located between the epidermis and body wall muscles—sense noxious thermal, mechanical, and light stimuli, and thus transmit information to the central nervous system to trigger avoidance behaviors.
The environment controls the growth of these dendrites in unexpected ways and becomes more complex. This means that a poor diet low in yeast causes Overdrying of bifurcations,” adds first author Yasutsu Kanaoka.
After systematically searching for key nutrients, the team found that the hypertrophic phenotype was not caused by low concentrations of amino acids—typical yeast nutrients—but rather by simultaneous deficiencies in vitamins, mineral ions, and cholesterol.
This deficiency increases the production of wingless signaling molecules from the body wall muscles. After C4da neurons receive Wingless neurons, they activate a protein called Akt, which promotes complex branching of dendrites.
“While this overgrowth of C4da neurons despite a nutrient-poor environment is inconsequential, it also intrigued us that these neurons became less responsive to noxious light stimuli,” explains Tadashi Uemura.
“Our study raises the possibility that the nutrient-dependent development of somatosensory neurons may play a role in optimizing the trade-off between seeking nutrient-rich foods and escaping from harmful environmental threats.”
Using cell-type-specific knockout systems—an established method of inactivating specific gene functions in a cell-specific way—the team identified the signals between organs that regulate the hypersynaptic phenotype.
“By focusing on the mechanism by which nutritional information is transmitted from the gut to the muscles, we may unravel the molecular mystery linking food and health.”
About this research in Neuroscience News
author: Jake J Tobyama
Source: Kyoto University
Contact: Jake G Tobyama – Kyoto University
picture: Image credit: KyotoU/Biostudies/Uemura Lab
Original search: open access.
“Intraorganic Wingless/Ror/Akt signaling regulates nutrient-dependent hypersynapsis in somatosensory neurons” by Tadashi Uemura et al. eLife
Wingless/Ror/Akt interorgan signaling regulates nutrient-dependent hypersynapsis in somatosensory neurons
Nutrition in early life has profound effects on the organism, altering processes such as organ formation. However, little is known about how specific nutrients affect nerve cell development.
Dendrites of class IV dendritic neurons in Drosophila Larvae become more complex when they are reared on a low yeast diet compared to a diet high in yeast.
Our systematic search for key nutrients revealed that neurons increase their peripheral dendritic density in response to combined deficiencies in vitamins, mineral ions, and cholesterol. The lack of these nutrients leads to the regulation of the muscles of the body wall, which are located near the tissues.
Wingless muscle-derived Akt activates in neurons through the receptor tyrosine kinase RoR, which promotes dendrite branching. In larvae muscles express wingless It is regulated not only in this major nutrient-dependent manner, but also through the JAK/STAT signaling pathway.
In addition, a low yeast diet limits neuronal response to light and light avoidance behaviour, which may help larvae improve survival strategies under reduced feeding conditions.
Together, our studies demonstrate how the availability of specific nutrients affects the development of neurons through signals between organs.