Diseases, Conditions, Syndromes

Neuropeptide reduces epileptic seizures in human brain tissue

One challenge facing researchers who study brain diseases is that for understandable reasons it is difficult to obtain human brain tissue for experiments. For that reason, experimental models are used, such as rodent studies, ...

Neuroscience

Memory like a sieve – or not

Humans are not only capable of forming memories but also recalling these memories years later. However, with advancing age many of us face difficulties with forming new memories, a process usually referred to as age-induced ...

Neuroscience

Is foraging behaviour regulated the same way in humans and worms?

How does our nervous system motivate us to get off the sofa and walk to the fridge, or even to the supermarket, to get food? A research team led by Alexander Gottschalk from Goethe University investigated this using the threadworm ...

Health

Analyzing a worm's sleep

Elephants, cats, flies, and even worms sleep. It is a natural part of many animals' lives. New research from Caltech takes a deeper look at sleep in the tiny roundworm Caenorhabditis elegans, or C. elegans, finding three ...

Neuroscience

New research unravels complex stroke mechanisms

New research at the University of Adelaide has led to a deeper understanding of how the brain responds to stroke and which mechanisms may be harmful or beneficial following a stroke.

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Neuropeptide

Neuropeptides are small protein-like molecules used by neurons to communicate with each other. They are neuronal signaling molecules, influence the activity of the brain in specific ways and are thus involved in particular brain functions, like analgesia, reward, food intake, learning and memory.

Neuropeptides are expressed and released by neurons, and mediate or modulate neuronal communication by acting on cell surface receptors. The human genome contains about 90 genes that encode precursors of neuropeptides. At present about 100 different peptides are known to be released by different populations of neurons in the mammalian brain. Neurons use many different chemical signals to communicate information, including neurotransmitters, peptides, cannabinoids, and even some gases, like nitric oxide.

Many populations of neurons have distinctive biochemical phenotypes. For example, in one subpopulation of about 3000 neurons in the arcuate nucleus of the hypothalamus, three anorectic peptides are co-expressed: α-melanocyte-stimulating hormone (α-MSH), galanin-like peptide, and cocaine-and-amphetamine-regulated transcript (CART), and in another subpopulation two orexigenic peptides are co-expressed, neuropeptide Y and agouti-related peptide (AGRP). These are not the only peptides in the arcuate nucleus; β-endorphin, dynorphin, enkephalin, galanin, ghrelin, growth-hormone releasing hormone, neurotensin, neuromedin U, and somatostatin are also expressed in subpopulations of arcuate neurons. These peptides are all released centrally and act on other neurons at specific receptors. The neuropeptide Y neurons also make the classical inhibitory neurotransmitter GABA.

Invertebrates also have many neuropeptides. CCAP has several functions including regulating heart rate, allatostatin and proctolin regulate food intake and growth, bursicon controls tanning of the cuticle and corazonin has a role in cuticle pigmentation and moulting.

Peptide signals play a role in information processing that is different from that of conventional neurotransmitters, and many appear to be particularly associated with specific behaviours. For example, oxytocin and vasopressin have striking and specific effects on social behaviours, including maternal behaviour and pair bonding.

This text uses material from Wikipedia, licensed under CC BY-SA