Dopamine single neurons

A single neuron-like PC 12 cell was trapped in an etched glass (30 pm deep) pocket sealed against a PDMS channel layer (20 pm). Quantal release of dopamine (in transient exocytosis) from the cell as stimulated by nicotine was amper-ometrically detected with a carbon fiber electrode. The cells flow into the channels caused by the liquid pressure which was provided by a liquid height at the sample reservoir (e.g., 0.5-2 mm). To facilitate transport of cells in the microchannels, the cell density should not be higher than lOVmL. Serious cell adhesion occurred if the transport speed was low (as provided by liquid height below 0.5 mm),... 

Olefirowicz, T. M. and Ewing, A. G, Dopamine concentration in the cytoplasmic compartment of single neurons determined by capillary electrophoresis, J. Neurosci. Methods, 34, 11-15, 1990. 

There are numerous transmitter substances. They include the amino acids glutamate, GABA and glycine acetylcholine the monoamines dopamine, noradrenaline and serotonin the neuropeptides ATP and NO. Many neurones use not a single transmitter but two or even more, a phenomenon called cotransmission. Chemical synaptic transmission hence is diversified. The basic steps, however, are similar across all neurones, irrespective of their transmitter, with the exception of NO transmitter production and vesicular storage transmitter release postsynaptic receptor activation and transmitter inactivation. Figure 1 shows an overview. Nitrergic transmission, i.e. transmission by NO, differs from transmission by other transmitters and is not covered in this essay. 

Blackburn T., Suzuki K, Ashby C., Jr. (2006). The acute and chronic administration of the 5-HT (2B/2C) receptor antagonist SB-200646A significantly alters the activity of spontaneously active midbrain dopamine neurons in the rat an in vivo extracellular single cell study. Synapse. 59, 502-12. 

FIGURE 7—42. Adrenergic combo 3 The actions of bupropion at dopamine neurons can be double-boosted by a direct-acting dopamine D2 and D3 agonist such as pramipexole. Norepinephrine is also single-boosted by bupropion. 

The use of fast scan cyclic voltammetry has already been described (Section 8.6). In general, microelectrodes, in some cases modified by electrocatalysts, are making it possible to learn about biological events on the scale of a single cell. Among the more important achievements (Wightmann, 1996) is the monitoring of dopamine released after stimulation from neurons in the intact brain and involved in neurotransmission. 

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