Neurotransmitter secretion

Nerve growth factor snake venoms zinc, 6, 613 Neurospora crassa calcium transport, 6, 571 cation transport, 6, 559 Neurosporin, 6, 676 Neurotransmitters secretion calcium, 6, 595 Neutral complexes electrical properties, 6, 143 Neutron absorbers... 

The three best-known examples of biochemical oscillations were found during the decade 1965-1975 [40,41]. These include the peroxidase reaction, glycolytic oscillations in yeast and muscle, and the pulsatile release of cAMP signals in Dictyostelium amoebae (see Section V). Another decade passed before the development of Ca " " fluorescent probes led to the discovery of oscillations in intracellular Ca +. Oscillations in cytosolic Ca " " have since been found in a variety of cells where they can arise spontaneously, or after stimulation by hormones or neurotransmitters. Their period can range from seconds to minutes, depending on the cell type [56]. The oscillations are often accompanied by propagation of intracellular or intercellular Ca " " waves. The importance of Ca + oscillations and waves stems from the major role played by this ion in the control of many key cellular processes—for example, gene expression or neurotransmitter secretion. 

Neurochemical data indicate that opioid receptors in the brain are associated with presy-naptic structures, thus functioning by reducing neurotransmitter secretion. 

Peripherally, all organs are innervated sympathetically (as well as parasympatheti-cally), and in most cases the adrenergic action of this system is opposite to the cholinergic effects. The neurotransmitter secreted by the nerve endings is norepinephrine and, to a lesser extent, epinephrine. 

Noradrenaline is a neurotransmitter secreted by postganglionic neurones, the central nervous system, and by the adrenal medulla. It has powerful direct actions at ol and o2 adrenoceptors. Its 31 effects are similar to adrenaline but, unlike adrenaline, it has minimal 32 effects. 

In this chapter we first describe the composition of cellular membranes and their chemical architecture— the molecular structures that underlie their biological functions. Next, we consider the remarkable dynamic features of membranes, in which lipids and proteins move relative to each other. Cell adhesion, endocytosis, and the membrane fusion accompanying neurotransmitter secretion illustrate the dynamic role of membrane proteins. We then turn to the protein-mediated passage of solutes across membranes via transporters and ion channels. In later chapters we discuss the role of membranes in signal transduction (Chapters 12 and 23), energy transduction (Chapter 19), lipid synthesis (Chapter 21), and protein synthesis (Chapter 27). 

Verhage M, Maia AS, Plomp JJ, Brussaard AB, Heeroma JH, et al. (2000) Synaptic assembly of the brain in the absence of neurotransmitter secretion. Science 287 864—9 Wonnacott S (1997) Presynaptic nicotinic ACh receptors. Trends Neurosd 20 92-8 Weber T, Zemelman BV, McNew JA, Westermann B, Gmachl M, Parlati F, Sollner TH, Rothman JE (1998) SNAREpins minimal machinery for membrane fusion. Cell 92 759-72 Whittaker VP, Sheridan MN (1965) The morphology and acetylcholine content of isolated cerebral cortical synaptic vesicles. J Neurochem 12 363-72 Xu J, Mashimo T, Siidhof TC (2007) Synaptotagmin-1, -2, and -9 Ca2+ sensors for fast release that spedfy distinct presynaptic properties in subsets of neurons. Neuron 54 567-81 Zucker RS, Regehr WG (2002) Short-term synaptic plasticity. Annu Rev Physiol 64 355 405... 

Detection of Neurotransmitter Secretion Through Amperometric Recordings---- 29... 

Most trivalent cations, at 50-100pM, block previously inserted channels (Scheer 1989 Hurlbut et al. 1994 Van Renterghem et al. 2000) and inhibit a-LTX-mediated Ca2+-uptake, while La3+ blocks depolarization as well (Scheer 1989). Channel inhibition by trivalent cations is very important because La3+ is essentially the only reagent that blocks the Ca2+-independent a-LTX-evoked neurotransmitter secretion in neurons (Scheer 1989 Capogna et al. 2003). 

Vaughan PF, Walker JH, Peers C (1998) The regulation of neurotransmitter secretion by protein kinase C. Mol Neurobiol 18 125-55... 

O Connor V, Heuss C, De Bello WM, Dresbach T, Charlton MP, Hunt JH, Pellegrini LL, Hodel A, Burger MM, Betz H, Augustine GJ, Schafer T. Disruption of syntaxin-mediated protein 45. interactions blocks neurotransmitter secretion. Proc. Natl. Acad. 

Caged Ca + [14] has been the most widely used caged compound. This fact can be explained by the importance of Ca + in cellular physiology and the existence of Ca + sensitive dyes. It has led to tremendous progress in the understanding of neurotransmitter secretion. 

Ion channels are essential for a wide range of functions such as neurotransmitters secretion and muscle contraction. Ion channels mediate Na, Ca +, and Cl conductance induced by membrane potential changes. These channels propagate action potentials in excitable cells and are also involved in the regulation of membrane potential and intracellular Ca + transients in most eukaryotic cells. About 300 genes code for subunits of voltage-gated ion channels. 

This last section presents recent experiments involving effects of calcium channel blocking drugs in whole animals. It is suggested that the following results reflect modification of brain neurotransmitter secretion by blockade of calcium channels. 

In the United Kingdom, for example, women whose birth weight was less than 6.6 pounds have an increased risk of depression at age 26 years. In men, those born weighing less than 5.5 pounds are more likely to be psychologically distressed at age 16 years and to report a history of depression at age 26 years. It s apparent that impaired neurodevelopment during fetal life may increase susceptibility to depression.56 This is consistent with the idea that fetal programming may affect hormones and neurotransmitter secretions that influence later mental and physical health.57... 

Hengstenberg, A., Blochl, A., Dietzel, l.D. and Schuhmann, W. (2001) Spatially resolved detection of neurotransmitter secretion from individual cells by means of scanning electrochemical microscopy. Angewendte Chemie, International Edition,40, 905-908. 

Figure 1 Schematic depicting the experimental arrangement used for measuring neurotransmitter secretion from a single cell (A) and representative amperometiic data obtained from a single PC 12 cell (B). A portion of the data shown in B is also displayed at a smaller time and current scale (C). Data was obtained using a 5 pm carbon fiber electrode held at 0.65 V vs. SSCE.

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