Biomaterial Database

Cholinergic nerve terminals of human cerebral cortex possess a GABA transporter whose activation induces release of acetylcholine. 1991

G Bonanno, and A Ruelle, and G C Andrioli, and M Raiteri

Instituto di Farmacologia e Farmacognosia, Università degli Studi di Genova, Italy.

The effect of gamma-aminobutyric acid (GABA) on the release of [3H]acetylcholine [( 3H]ACh) from human cerebral cortex nerve terminals was investigated using synaptosomes prepared from neurosurgical specimens (which had to be removed to reach deeply located tumors) prelabeled with [3H]choline and exposed in superfusion to varying concentrations of GABA. The amino acid (3-100 microM) increased in a concentration-dependent manner (maximal effect: 40%; EC50 = 14.7 microM) the release of [3H]ACh but not that of [3H]choline. The GABAA receptor agonist muscimol (up to 100 microM) did not increase significantly the release of [3H]ACh. Accordingly, the effect of GABA was insensitive to the GABAA receptor antagonist bicuculline. The release of [3H]ACh was not affected by the GABAB receptor agonist (-)-baclofen (100-300 microM). The GABA-induced [3H]ACh release was counteracted by two inhibitors of GABA uptake, N-(4,4-diphenyl-3-butenyl)nipecotic acid (SKF 89976A) and nipecotic acid. Moreover, the enhancing effect of GABA on [3H]ACh release was clearly Na+-dependent and was reduced by almost 90% in presence of 23 mM NaCl. The data indicate that, similarly to what had been observed in the rat, cholinergic nerve terminals in the human cerebral cortex possess a GABA transporter. Activation of this carrier brings about release of newly synthesized ACh. GABA and ACh might co-exist in some cerebrocortical nerve endings in the vertebrate brain, including man.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009118	Muscimol	A neurotoxic isoxazole isolated from species of AMANITA. It is obtained by decarboxylation of IBOTENIC ACID. Muscimol is a potent agonist of GABA-A RECEPTORS and is used mainly as an experimental tool in animal and tissue studies.	Agarin,Pantherine
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
D009419	Nerve Tissue Proteins		Proteins, Nerve Tissue,Tissue Proteins, Nerve
D009557	Nipecotic Acids		Acids, Nipecotic
D010275	Parasympathetic Nervous System	The craniosacral division of the autonomic nervous system. The cell bodies of the parasympathetic preganglionic fibers are in brain stem nuclei and in the sacral spinal cord. They synapse in cranial autonomic ganglia or in terminal ganglia near target organs. The parasympathetic nervous system generally acts to conserve resources and restore homeostasis, often with effects reciprocal to the sympathetic nervous system.	Nervous System, Parasympathetic,Nervous Systems, Parasympathetic,Parasympathetic Nervous Systems,System, Parasympathetic Nervous,Systems, Parasympathetic Nervous
D011392	Proline	A non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.	L-Proline,L Proline
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier