Synapse nitric oxide

An additional and widespread neuroactive (transmitter-like) compound is nitric oxide (NO). This gaseous secretion is a product of the action of the enzyme NO-synthase on arginine. It is implicated in at least two roles within the non-sensory tissues of the organ, and at particular synapses in the AOB. One nitric oxidergic effect is initiated by the nerve fibres supplying the smooth muscle component of the vasomotor tissues. The other effect is the expected action of NO on the output... 

Datta, S., Patterson, E. H. Siwek, D. F. (1997). Endogenous and exogenous nitric oxide in the pedunculopontine tegmentum induces sleep. Synapse 27, 69-78. 

Endogenous nitric oxide plays an important role as a messenger between neurons at synapses in the central nervous system [11] and fulfills the major... 

Campeau S, Miserendino MJD, Davis M (1992) Intra-amygdala infusion of the N-methyl-D-asparate receptor antagonist AP5 blocks acquisition but not expression of fear-potentiated startle to an auditory conditioned stimulus. Behav Neurosci 106 569-574 Caton P, Tousman SA, Quock RM (1994) Involvement of nitric oxide in nitrous oxide anxiolysis in the elevated plus-maze. Pharmacol Biochem Behav 48 689-692 Chapman P, Kairiss EW, Keenan CL, Brown TH (1990) Long-term synaptic potentiation in the amygdala. Synapse 6 271-278... 

Inactive neuron with synapses potentially weakened by nitric oxide... 

Neurons send electrical impulses from one part of the cell to another part of the same cell via their axons, but these electrical impulses do not jump directly to other neurons. Neurons communicate by one neuron hurling a chemical messenger, or neurotransmitter, at the receptors of a second neuron. This happens frequently, but not exclusively, at the sites of synaptic connections between them (Fig. 1 — 3). Communication between neurons is therefore chemical, not electrical. That is, an electrical impulse in the first neuron is converted to a chemical signal at the synapse between it and a second neuron, in a process known as chemical neurotransmission. This occurs predominantly in one direction, from the presynaptic axon terminal, to any of a variety of sites on a second postsynaptic neuron. However, it is increasingly apparent that the postsynaptic neuron can also talk back to the presynaptic neuron with chemical messengers of its own, perhaps such as the neurotransmitter nitric oxide. The frequency and extent of such cross-communication may determine how... 

Only the first type of neurotransmitter release mediates the fast point-to-point synaptic transmission process at classical synapses (sometimes referred to as wiring transmission). All of the other types of neurotransmitter release effect one or another form of volume transmission whereby the neurotransmitter signal acts diffusely over more prolonged time periods (Agnati et al., 1995). Of these volume transmitter pathways, the time constants and volumes involved differ considerably. For example, diffusible neurotransmitters such as nitric oxide act relatively briefly in a localized manner, whereas at least some neuropeptides act on the whole brain, and can additionally act outside of it (i.e., function as hormones). There is an overlap between wiring and volume neurotransmission in that all classical neurotransmitters act as wiring transmitters via ionotropic receptors, and also act as volume transmitters via G-protein-coupled receptors. Moreover, neuromodulators in turn feed back onto classical synaptic transmission. 

Ding JD, Burette A, Nedvetsky PI, Schmidt HH, Weinberg RJ (2004) Distribution of soluble guanylyl cyclase in the rat brain. J Comp Neurol 472 437 18 Doreulee N, Brown RE, Yanovsky Y, Godecke A, Schrader J, Haas HL (2001) Defective hippocampal mossy fiber long-term potentiation in endothelial nitric oxide synthase knockout mice. Synapse 41 191—4... 

Sporns O, Jenkinson S (1997) Potassium ion- and nitric oxide-induced exocytosis from populations of hippocampal synapses during synaptic maturation in vitro. Neuroscience 80 1057-73 Stamler JS, Toone EJ, Lipton SA, Sucher NJ (1997) (S)NO signals Translocation, regulation, and a consensus motif. Neuron 18 691-6... 

Thomas S, Robitaille R. 2001. Differential Frequency-Dependent Regulation of Transmitter Release by Endogenous Nitric Oxide at the Amphibian Neuromuscular Synapse. J Neurosci 21 1087-1095. 

The processes responsible for the selection of the appropriate output for a particular mossy fiber-parallel fiber input may function at the level of the synapses of the mossy fibers with granule cells, unipolar brush cells, or Golgi cells and at the level of the parallel fiber-Purkinje cell synapse. Several systems may be involved in this selection process. Nitric oxide, that is synthetized by subsets of granule cells (Schilling et ah, 1994 Hawkes and Turner, 1994) and in stellate and basket cells (Bredt et ah, 1990) (Section... 

Crepel F, Jaillard D (1990) Protein kinase, nitric oxide and long-term depression of synapse in the cerebellum. Neuroreport, 1, 133-136. 

Fig. 18.4. Glutamate or NMDA receptors in the central nervous system. Binding of agonists (glutamate or NMDA) opens the channel, allowing potassium ions to flow outward to extracellular fluid (ECF) and sodium and calcium ions to flow into the nerve cells. Increased intracellular (IGF) calcium ion concentration triggers a cascade that produces a response and liberates the neuronal messenger nitric oxide (NO). Ketamine may produce anesthesia by blocking these NMDA-controlled channels, which are located at excitatory synapses on pyramidal cells (3). Glycine acts as a positive allosteric modulator at the NMDA receptor.

Nitric oxide synthase III inununoreactivity was observed in the dendrites of hippocampal pyramidal cells of knockout and wild type animals indicating that even in functional NOS-III knockouts the non-deleted N-terminal trunk of the protein is still expressed (Zanger et al. 1999). NOS-III immuno-reactivity for the C-terminal portion of the protein was found in wild types only. Electron microscopically NOS-III immunoreactivity was not located at synapses but was present in and associated with mitochondria which were mainly located in dendrites compared to the soma and were never seen in axons. 

Ibiza, S., Victor, V.M., Bosca, I., Ortega, A., Urzainqui, A., O Connor, J.E., Sanchez-Madrid, E, Esplugues, J.V., and Serrador, J.M. (2006). Endothelial nitric oxide synthase regulates T cell receptor signaling at the immunological synapse. Immunity. 24, 753-765. 

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