Related Experiment Video
Updated: Apr 24, 2026
08:14
Extraction of Non-Protein Amino Acids from Cyanobacteria for Liquid Chromatography-Tandem Mass Spectrometry Analysis
Published on: December 9, 2022
4.0K
Brain amino acid sensing
T Tsurugizawa1, H Uneyama, K Torii
1Institute for Innovation, Ajinomoto Co., Inc., Kawasaki-ku, Kawasaki-shi, Japan.
Diabetes, Obesity & Metabolism
|September 10, 2014
Summary
The gut-brain axis uses glutamate signaling to maintain amino acid balance and regulate appetite. This discovery highlights how the body identifies nutrient deficiencies, promoting healthier eating habits.
Area of Science:
- Neuroscience
- Metabolic Physiology
- Nutritional Science
Background:
- Amino acid levels in blood and brain remain constant daily, irrespective of food intake.
- Gastric vagal afferents detect free glutamate and sugars, initiating digestion and signaling food intake.
- Glutamate signaling via the gut-brain axis controls amino acid homeostasis and diet-induced thermogenesis.
Purpose of the Study:
- To investigate the role of glutamate signaling in nutrient homeostasis and appetite regulation.
- To explore the body's mechanisms for identifying and correcting nutrient deficiencies.
- To understand the impact of diet composition on obesity and metabolic health.
Main Methods:
- Observational studies on rats fed high-sugar and high-fat diets with and without monosodium glutamate (MSG) solutions.
- Induction of lysine deficiency in rats to observe adaptive plasticity.
- Analysis of brain activity, particularly in the lateral hypothalamic area (LHA), in response to nutrient availability and taste signals.
Main Results:
- Rats fed high-sugar/high-fat diets did not become obese when offered MSG solutions.
- Lysine deficiency induced specific plasticity in rats, demonstrating nutrient identification.
- Activin A activity in the LHA mediated this plastic effect, linking glutamate signaling to nutrient intake regulation.
- MSG solutions were preferred by rats post-malnutrition, serving as biomarkers for protein status.
Conclusions:
- Glutamate signaling through the gut-brain axis is crucial for maintaining amino acid homeostasis and regulating appetite.
- The brain can detect nutrient deficiencies and induce adaptive responses to restore balance.
- Umami taste perception, mediated by glutamate, plays a key role in regulating the ingestion of deficient nutrients, potentially preventing obesity and promoting health.
Related Concept Videos
01:29Amino Acid Biosynthetic Pathways
1.7K
Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which...
1.7K
03:42Amino acids
72.6K
Amino acids are the monomers that comprise proteins. Each amino acid has the same fundamental structure, which consists of a central carbon atom, or the alpha (α) carbon, bonded to an amino group (NH2), a carboxyl group (COOH), and to a hydrogen atom. Every amino acid also has another atom or group of atoms bonded to the central atom known as the R group. There are 20 common amino acids present in proteins, each with a different R group. Variation in the amino acid sequence is responsible...
72.6K
01:18Amino Acid Catabolism
1.7K
Microorganisms rely on proteins as an essential carbon and energy source, particularly in environments with limited polysaccharides or lipids. However, proteins are too large to cross the plasma membrane unaided, necessitating enzymatic degradation. Microbes secrete extracellular proteases and peptidases that hydrolyze proteins into peptides, which can then be transported across the membrane. Once inside the cell, intracellular proteases degrade these peptides into free amino acids, which...
1.7K
01:19NMR Spectroscopy Of Amines
9.9K
In proton NMR spectroscopy, primary amines and secondary amines showcase their N–H protons as a broad signal in the chemical shift range between δ 0.5 and 5 ppm. The exact position in this range depends on several factors, including sample concentration, hydrogen bonding, and the type of solvent used. Since amine protons undergo fast proton exchange in solution, the protons are labile and therefore do not participate in any splitting with adjacent protons. Thus, the observed peak is...
9.9K
01:24The Physiology of Taste
6.7K
The perception of a salty flavor is facilitated by sodium ions within the oral salivary fluid. Upon consumption of a salty substance, salt crystals disassemble, leading to the liberation of its constituents—Na+ and Cl- ions. These ions subsequently dissolve into the salivary fluid present in the oral cavity. The external environment of the gustatory cells experiences an elevation in Na+ concentration, thereby establishing a potent concentration gradient. This gradient propels the...
6.7K
02:26tRNA Activation
17.8K
Aminoacyl-tRNA synthetases are present in both eukaryotes and bacteria. Though eukaryotes have 20 different aminoacyl-tRNA synthetases to couple to 20 amino acids, many bacteria do not have genes for all of these aminoacyl-tRNA synthetases. Despite this, they still use all 20 amino acids to synthesize their proteins. For instance, some bacteria do not have the gene encoding the enzyme that couples glutamine with its partner tRNA. In these organisms, one enzyme adds glutamic acid to all of the...
17.8K