Roles of Nutrients in the Brain Development, Cognitive Function, and Mood of Dogs and Cats

The brainBrain is the central commander of all physical activities and the expression of emotions in animalsAnimal. Its developmentDevelopment and cognitiveCognitive healthHealth critically depend on the neural network that consists of neurons, glial cells (namely, non-neuronal cells), and neurotransmittersNeurotransmitter (communicators between neurons). The latter include proteinogenic amino acidsAmino acid (e.g., L-glutamateGlutamate, L-aspartateAspartate, and glycineGlycine) and their metabolitesMetabolites [e.g., γ-aminobutyrate, D-aspartate, D-serine, nitric oxideNitric oxide, carbon monoxide, hydrogen sulfide, and monoamines (e.g., dopamine, norepinephrine, epinephrine, and serotoninSerotonin)]. In addition, some non-neurotransmitterNeurotransmitter metabolitesMetabolites of amino acidsAmino acid, such as taurineTaurine, creatine, and carnosine, also play important roles in brainBrain developmentDevelopment, cognitiveCognitive healthHealth, behaviorBehavior, and moodMood of dogsDog and catsCat. Much evidence shows that catsCat require dietary ω3 (α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acidDocosahexaenoic acid) and ω6 (linoleic acidLinoleic acid and arachidonic acidArachidonic acid) polyunsaturatedPolyunsaturated fatty acidsFatty acid for the developmentDevelopment of the central nervous system. As an essentialEssential component of membranesMembrane of neurons and glial cells, cholesterolCholesterol is also crucial for cognitiveCognitive developmentDevelopment and functionFunction. In addition, vitamins and minerals are required for the metabolism of AAs, lipids, and glucose in the nervous system, and also act as antioxidants. Thus, inadequate ProteinLipidnutritionNutrition will lead to moodMood disordersDisorder. Some amino acidsAmino acid (e.g., arginineArginine, glycineGlycine, methionineMethionine, serineSerine, taurineTaurine, tryptophanTryptophan, and tyrosineTyrosine) can help to alleviate behavioral and moodMood disordersDisorder (e.g., depressionDepression, anxietyAnxiety and aggressionAggression). As abundant providers of all these functional amino acidsAmino acid and lipidsLipid, animalAnimal-sourced foodsFood (e.g., liverLiver, intestinal mucosa, and meat) play important roles in brainBrain developmentDevelopment, cognitiveCognitive functionFunction, and moodMood of dogsDog and catsCat. This may explain, in part, why dogsDog and catsCat prefer to eat visceralVisceral organs of their preyPrey. Adequate provision of nutrients in all phases of the life cycle (pregnancyPregnancy, lactationLactation, postnatal growthGrowth, and adulthood) is essentialEssential for optimizing neurological healthHealth, while preventing cognitiveCognitive dysfunctionDysfunction and abnormal behaviorBehavior.