Biomaterial Database

Fine structural localization of acetylcholinesterase in electroplaque of the electric eel. 1966

F E Bloom, and R J Barrnett

The electroplaques composing the electric organ of the eel, Electrophorus electricus, have been utilized for the dual purpose of demonstrating the subcellular sites of acetylcholinesterase activity and as a model for comparison of the several cytochemical methods available. Fresh tissue and tissue fixed by immersion in formalin, hydroxyadipaldehyde, or glutaraldehyde was reacted with the Cu-thiocholine method, the Cu-ferrocyanide thiocholine method, or the thiolacetic acid (TAA) method using Pb, Ag, or Au as capture reagents. Controls were obtained by omission of substrate, or by addition to complete media of varying concentrations of different cholinesterase inhibitors. Reactions were run at 0-5 degrees C at a pH range of 5.0-7.1 for 0.25 to 120 min. Regardless of the capture metal, the localization obtained with TAA as substrate was identical with that observed with acetylthiocholine, the majority of precipitate being deposited on or near the external innervated surface of the plaque and within the tubulovesicular organelles opening onto the innervated surface. Both of the thiocholine methods and the Pb-TAA method showed reaction product in synaptic vesicles of the nerve endings innervating the plaque which was uninhibitable by 10(-4)M physostigmine. All methods also showed some inhibitor-sensitive deposition of reaction product in the mucoid material forming the immediate extracellular environment of the innervated surface.

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D009411	Nerve Endings	Branch-like terminations of NERVE FIBERS, sensory or motor NEURONS. Endings of sensory neurons are the beginnings of afferent pathway to the CENTRAL NERVOUS SYSTEM. Endings of motor neurons are the terminals of axons at the muscle cells. Nerve endings which release neurotransmitters are called PRESYNAPTIC TERMINALS.	Ending, Nerve,Endings, Nerve,Nerve Ending
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D002800	Cholinesterase Inhibitors	Drugs that inhibit cholinesterases. The neurotransmitter ACETYLCHOLINE is rapidly hydrolyzed, and thereby inactivated, by cholinesterases. When cholinesterases are inhibited, the action of endogenously released acetylcholine at cholinergic synapses is potentiated. Cholinesterase inhibitors are widely used clinically for their potentiation of cholinergic inputs to the gastrointestinal tract and urinary bladder, the eye, and skeletal muscles; they are also used for their effects on the heart and the central nervous system.	Acetylcholinesterase Inhibitor,Acetylcholinesterase Inhibitors,Anti-Cholinesterase,Anticholinesterase,Anticholinesterase Agent,Anticholinesterase Agents,Anticholinesterase Drug,Cholinesterase Inhibitor,Anti-Cholinesterases,Anticholinesterase Drugs,Anticholinesterases,Cholinesterase Inhibitors, Irreversible,Cholinesterase Inhibitors, Reversible,Agent, Anticholinesterase,Agents, Anticholinesterase,Anti Cholinesterase,Anti Cholinesterases,Drug, Anticholinesterase,Drugs, Anticholinesterase,Inhibitor, Acetylcholinesterase,Inhibitor, Cholinesterase,Inhibitors, Acetylcholinesterase,Inhibitors, Cholinesterase,Inhibitors, Irreversible Cholinesterase,Inhibitors, Reversible Cholinesterase,Irreversible Cholinesterase Inhibitors,Reversible Cholinesterase Inhibitors
D003593	Cytoplasm	The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Protoplasm,Cytoplasms,Protoplasms
D003594	Cytoplasmic Granules	Condensed areas of cellular material that may be bounded by a membrane.	Cytoplasmic Granule,Granule, Cytoplasmic,Granules, Cytoplasmic
D004524	Eels	Common name for an order (Anguilliformes) of voracious, elongate, snakelike teleost fishes.	Anguilliformes,Eel
D004557	Electric Organ	In about 250 species of electric fishes, modified muscle fibers forming disklike multinucleate plates arranged in stacks like batteries in series and embedded in a gelatinous matrix. A large torpedo ray may have half a million plates. Muscles in different parts of the body may be modified, i.e., the trunk and tail in the electric eel, the hyobranchial apparatus in the electric ray, and extrinsic eye muscles in the stargazers. Powerful electric organs emit pulses in brief bursts several times a second. They serve to stun prey and ward off predators. A large torpedo ray can produce of shock of more than 200 volts, capable of stunning a human. (Storer et al., General Zoology, 6th ed, p672)	Electric Organs,Organ, Electric,Organs, Electric
D006056	Golgi Apparatus	A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)	Golgi Complex,Apparatus, Golgi,Complex, Golgi