The myenteric plexus provides motor innervation to both layers of the muscular layer of the gut, having both parasympathetic and sympathetic input, whereas the submucous plexus provides secretomotor innervation to the mucosa nearest the lumen of the gut.
Enflurane is a halogenated ether. Developed by Ross Terrell in 1963, it was first used clinically in 1966. It was increasingly used for inhalational anesthesia during the 1970s and 1980s but is no longer in common use.
Neuropharmacology is the study of how drugs affect function in the nervous system, and the neural mechanisms through which they influence behavior. There are two main branches of neuropharmacology: behavioral and molecular. Behavioral neuropharmacology focuses on the study of how drugs affect human behavior (neuropsychopharmacology), including the study of how drug dependence and addiction affect the human brain. Molecular neuropharmacology involves the study of neurons and their neurochemical interactions, with the overall goal of developing drugs that have beneficial effects on neurological function. Both of these fields are closely connected, since both are concerned with the interactions of neurotransmitters, neuropeptides, neurohormones, neuromodulators, enzymes, second messengers, co-transporters, ion channels, and receptor proteins in the central and peripheral nervous systems. Studying these interactions, researchers are developing drugs to treat many different neurological disorders, including pain, neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, psychological disorders, addiction, and many others.
The glycine receptor is the receptor of the amino acid neurotransmitter glycine. GlyR is an ionotropic receptor that produces its effects through chloride current. It is one of the most widely distributed inhibitory receptors in the central nervous system and has important roles in a variety of physiological processes, especially in mediating inhibitory neurotransmission in the spinal cord and brainstem.
The endocannabinoid system (ECS) is a biological system composed of endocannabinoids, which are endogenous lipid-based retrograde neurotransmitters that bind to cannabinoid receptors, and cannabinoid receptor proteins that are expressed throughout the vertebrate central nervous system and peripheral nervous system. The endocannabinoid system remains under preliminary research, but may be involved in regulating physiological and cognitive processes, including fertility, pregnancy, pre- and postnatal development, various activity of immune system, appetite, pain-sensation, mood, and memory, and in mediating the pharmacological effects of cannabis. The ECS plays an important role in multiple aspects of neural functions, including the control of movement and motor coordination, learning and memory, emotion and motivation, addictive-like behavior and pain modulation, among others.
Purinergic receptors, also known as purinoceptors, are a family of plasma membrane molecules that are found in almost all mammalian tissues. Within the field of purinergic signalling, these receptors have been implicated in learning and memory, locomotor and feeding behavior, and sleep. More specifically, they are involved in several cellular functions, including proliferation and migration of neural stem cells, vascular reactivity, apoptosis and cytokine secretion. These functions have not been well characterized and the effect of the extracellular microenvironment on their function is also poorly understood.
The P2X receptors, also ATP-gated P2X receptor cation channel family, is a protein family that consists of cation-permeable ligand-gated ion channels that open in response to the binding of extracellular adenosine 5'-triphosphate (ATP). They belong to a larger family of receptors known as the ENaC/P2X superfamily. ENaC and P2X receptors have similar 3-D structures and are homologous. P2X receptors are present in a diverse array of organisms including humans, mouse, rat, rabbit, chicken, zebrafish, bullfrog, fluke, and amoeba.
Endomorphins are considered to be natural opioid neurotransmitters central to pain relief. The two known endomorphins, endomorphin-1 and endomorphin-2, are tetrapeptides, consisting of Tyr-Pro-Trp-Phe and Tyr-Pro-Phe-Phe amino acid sequences respectively. These sequences fold into tertiary structures with high specificity and affinity for the μ-opioid receptor, binding it exclusively and strongly. Bound μ-opioid receptors typically induce inhibitory effects on neuronal activity. Endomorphin-like immunoreactivity exists within the central and peripheral nervous systems, where endomorphin-1 appears to be concentrated in the brain and upper brainstem, and endomorphin-2 in the spinal cord and lower brainstem. Because endomorphins activate the μ-opioid receptor, which is the target receptor of morphine and its derivatives, endomorphins possess significant potential as analgesics with reduced side effects and risk of addiction.
SK channels are a subfamily of calcium-activated potassium channels. They are so called because of their small single channel conductance in the order of 10 pS. SK channels are a type of ion channel allowing potassium cations to cross the cell membrane and are activated (opened) by an increase in the concentration of intracellular calcium through N-type calcium channels. Their activation limits the firing frequency of action potentials and is important for regulating afterhyperpolarization in the neurons of the central nervous system as well as many other types of electrically excitable cells. This is accomplished through the hyperpolarizing leak of positively charged potassium ions along their concentration gradient into the extracellular space. This hyperpolarization causes the membrane potential to become more negative. SK channels are thought to be involved in synaptic plasticity and therefore play important roles in learning and memory.
P2X purinoceptor 1, also ATP receptor, is a protein that in humans is encoded by the P2RX1 gene.
Potassium channel subfamily K member 2, also known as TREK-1, is a protein that in humans is encoded by the KCNK2 gene.
P2X purinoceptor 4 is a protein that in humans is encoded by the P2RX4 gene. P2X purinoceptor 4 is a member of the P2X receptor family. P2X receptors are trimeric protein complexes that can be homomeric or heteromeric. These receptors are ligand-gated cation channels that open in response to ATP binding. Each receptor subtype, determined by the subunit composition, varies in its affinity to ATP and desensitization kinetics.
Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 2, also known as KCNN2, is a protein which in humans is encoded by the KCNN2 gene. KCNN2 is an ion channel protein also known as KCa2.2.
P2X purinoceptor 3 is a protein that in humans is encoded by the P2RX3 gene.
Potassium intermediate/small conductance calcium-activated channel, subfamily N, member 1 , also known as KCNN1 is a human gene encoding the KCa2.1 protein.
A channel blocker is the biological mechanism in which a particular molecule is used to prevent the opening of ion channels in order to produce a physiological response in a cell. Channel blocking is conducted by different types of molecules, such as cations, anions, amino acids, and other chemicals. These blockers act as ion channel antagonists, preventing the response that is normally provided by the opening of the channel.
The following diagram is provided as an overview of and topical guide to the human nervous system:
Colin G. Nichols FRS is the Carl Cori Endowed Professor, and Director of the Center for Investigation of Membrane Excitability Diseases at Washington University in St. Louis, Missouri.
Graeme Henderson is a British neuroscientist whose research focuses on opioid addiction. He is professor of pharmacology in the School of Physiology, Pharmacology and Neuroscience, University of Bristol.
Raymond J Dingledine is an American pharmacologist and neurobiologist who has made considerable contributions to the field of epilepsy. He serves as Professor in the School of Medicine at Emory University, Atlanta GA, where he chaired the pharmacology department for 25 years and served as Executive Associate Dean of Research for 10 years.
