Metabotropic glutamate receptorThe metabotropic glutamate receptors, or mGluRs, are a type of glutamate receptor that are active through an indirect metabotropic process. They are members of the group C family of G-protein-coupled receptors, or GPCRs. Like all glutamate receptors, mGluRs bind with glutamate, an amino acid that functions as an excitatory neurotransmitter. The mGluRs perform a variety of functions in the central and peripheral nervous systems: For example, they are involved in learning, memory, anxiety, and the perception of pain.
NerveA nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. Axons transmit electrical impulses. Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system.
Dale's principleIn neuroscience, Dale's principle (or Dale's law) is a rule attributed to the English neuroscientist Henry Hallett Dale. The principle basically states that a neuron performs the same chemical action at all of its synaptic connections to other cells, regardless of the identity of the target cell. However, there has been disagreement about the precise wording. Because of an ambiguity in the original statement, there are actually two versions of the principle, one that has been shown definitively to be false, and another that remains a valuable rule of thumb.
Small fiber peripheral neuropathySmall fiber peripheral neuropathy is a type of peripheral neuropathy that occurs from damage to the small unmyelinated and myelinated peripheral nerve fibers. These fibers, categorized as C fibers and small Aδ fibers, are present in skin, peripheral nerves, and organs. The role of these nerves is to innervate the skin (somatic fibers) and help control autonomic function (autonomic fibers). It is estimated that 15–20 million people in the United States have some form of peripheral neuropathy.
Monosodium glutamateMonosodium glutamate (MSG), also known as sodium glutamate, is the sodium salt of glutamic acid. MSG is found naturally in some foods including tomatoes and cheese in this glutamic acid form. MSG is used in cooking as a flavor enhancer with an umami taste that intensifies the meaty, savory flavor of food, as naturally occurring glutamate does in foods such as stews and meat soups. MSG was first prepared in 1908 by Japanese biochemist Kikunae Ikeda, who was trying to isolate and duplicate the savory taste of kombu, an edible seaweed used as a broth (dashi) for Japanese cuisine.
ClonusClonus is a set of involuntary and rhythmic muscular contractions and relaxations. Clonus is a sign of certain neurological conditions, particularly associated with upper motor neuron lesions involving descending motor pathways, and in many cases is accompanied by spasticity (another form of hyperexcitability). Unlike small spontaneous twitches known as fasciculations (usually caused by lower motor neuron pathology), clonus causes large motions that are usually initiated by a reflex.