The Crosstalk Between Brain Mediators Regulating Food Intake Behavior in Birds: A Review

Abstract

Appetite is controlled by a complex system of central and peripheral signals interacting to modulate the ingestion response. Several brain mediators with complex networks adjust food intake in birds. Based on the available literature, these mediators have interactions with a number of other neurotransmitters (NT S ) involved in feed intake. It means that, NT S regulate feeding behavior through mediating other peptide and NTs activity. In birds, insulin known as a hypophagic hormone that is interplaying with neuropeptide Y (NPY), pro-opiomelanocortin (POMC), and corticotropin-releasing factor (CRF) in brain. Another hormone ghrelin, inhibits food intake in birds and other mediators, such as glutamate, endocannabinoid system (ECS), serotonin (5-hydroxytryptamine, 5-HT), and norepinephrine (NE), which play a key role in ghrelin-induced hypophagia. Another involved peptide on feeding behavior in chickens called nociceptin/orphanin FQ (N/OFQ) is modulated by histamine, glutamate, dopamine (DA), gamma-aminobutyric acid (GABA), agouti-related protein (AgRP), and cocaine and amphetamine-regulated transcript (CART). Some of the NT S such as opioid have both orexigenic and anorexigenic effects in birds while has interaction with NE, glutamate, histamine, DA, and cannabinoids (CBs). Thus, interaction among mediators is a prominent process needs to be considered in order to understanding the mechanisms underlying feed intake regulation in birds. This review aims to investigate the role of major regulators and their mediatory interactions with one another in poultry feeding behavior. According to mentioned interactions, it seems that dopamine, serotonin, and glutamate have the most interactions with other NT systems. Therefore, they play an axial role in the central regulation of food intake in CNS.

Investigation of structural and neurobiochemical differences in brains from high-performance and native hen breeds

“…Additionally, a significantly higher density of neurons was detected in the paraventricular nucleus (PVN) and the anterior hypothalamus (AH) in the brain of the Leghorn vs. Green-legged Partridge hens. Appetite is modulated by various regions of the CNS, and the most important role is assigned to the hypothalamus 21,22 . The ventromedial hypothalamus (VMH) and the paraventricular nucleus (PVN) analysed in the present study are examples of hypothalamic subregions involved in the expression of the feeding behaviour 23 .…”

Transcriptomics analysis unveils key potential genes associated with brain development and feeding behavior in the hypothalamus of L-citrulline-fed broiler chickens

“…Therefore, these findings may suggest the differential effects of LCT diet on these neuropeptides in order to promote thermal homeostasis, since they are largely involved in feed intake and energy balance. Additionally, it is probable that these neuropeptides responsible for feed intake may interact with other neurotransmitters to regulate appetite, energy homeostasis, and body temperature ( Rahmani et al, 2021 ). The central expression of anabolic neuropeptides (such as NPY, AgRP, MCH, and orexins) promotes food intake but suppresses metabolic rate causing hypothermia, whereas, catabolic neuropeptides (such as POMC and NMU) act to reduce food intake and increase energy expenditure with the tendency to induce hyperthermia ( Szekely et al, 2010 ).…”

The Effect of the Central Administration of the Neuropeptide VF on Feed Intake and Its Possible Interactions with Glutamate and Opioid Systems in Broiler Chicken

“…The induced balance between dietary intake and energy consumption resulting in the interaction of peripheral inputs with CNS is known as energy homeostasis. NTs and their regulatory nexus have a pivotal role in energy homeostasis in this regard (Rahmani et al 2021). Based on the results obtained, NPVF (16 nmol) can induce decreased feed intake in broilers after three hours of feeding restriction.…”