Neurotransmitters multiple

Traditionally receptors have been classified according to their pharmacology. Each neurotransmitter acts on its own family of receptors and these receptors show a high degree of specificity for their transmitter. Thus, the receptors on which acetylcholine (ACh) works do not respond to glutamate (or any other neurotransmitter) and vice versa. Diversity of neurotransmitter action is provided by the presence of multiple receptor subtypes for each neurotransmitter, all of which still remain specific to that neurotransmitter. This principle is illustrated by the simple observations outlined in... 

Non-motor symptoms are due to multiple neurotransmitter abnormalities throughout the brain, and some symptoms may be aggravated by PD medications. Sleep disturbance can affect more than 70% of PD patients and includes insomnia, sleep... 

Axon terminal with multiple varicosities releases neurotransmitter over wide surface area affecting many tissue cells Gap junctions allow spread of nervous stimulation throughout tissue... 

Synapses between the autonomic postganglionic neuron and effector tissue — the neuroeffector junction — differ greatly from the neuron-to-neuron synapses discussed previously in Chapter 5 (see Table 9.1). The postganglionic fibers in the ANS do not terminate in a single swelling like the synaptic knob, nor do they synapse directly with the cells of a tissue. Instead, the axon terminals branch and contain multiple swellings called varicosities that lie across the surface of the tissue. When the neuron is stimulated, these varicosities release neurotransmitter over a large surface area of the effector tissue. This diffuse release of the neurotransmitter affects many tissue cells simultaneously. Furthermore, cardiac muscle and most smooth muscle have gap junctions between cells. These specialized intercellular communications... 

Mulder AH and Schoffelmeer ANM (1993). Multiple opioid receptors and presynaptic modulation of neurotransmitter release in the brain. In A Herz (ed.), Opioids. I Handbook of Experimental Pharmacology (Vol. 104, pp. 125-144). Springer-Verlag, New York. 

One characteristic of regulated exocytosis is the ability to store secretory vesicles in a reserve pool for utilization upon stimulation. In the presynaptic terminal, this principle is expanded to define multiple pools of synaptic vesicles a ready releasable pool, a recycled synaptic vesicle pool and a larger reserve pool. This reserve pool assures that neurotransmitter is available for release in response to even the highest physiological demands. Neurons can fire so many times per minute because synaptic vesicles from the ready releasable pool at a given synapse undergo exocytosis in response to a single action potential. 

Chemical transmission between nerve cells involves multiple steps 167 Neurotransmitter release is a highly specialized form of the secretory process that occurs in virtually all eukaryotic cells 168 A variety of methods have been developed to study exocytosis 169 The neuromuscular junction is a well defined structure that mediates the presynaptic release and postsynaptic effects of acetylcholine 170 Quantal analysis defines the mechanism of release as exocytosis 172 Ca2+ is necessary for transmission at the neuromuscular junction and other synapses and plays a special role in exocytosis 174 Presynaptic events during synaptic transmission are rapid, dynamic and interconnected 175... 

Purines such as ATP and adenosine play a central role in the energy metabolism of all life forms. This fact probably delayed recognition of other roles for purines as autocrine and paracrine substances and neurotransmitters. Today it is recognized that purines are released from neurons and other cells and that they produce widespread effects on multiple organ systems by binding to purinergic receptors located on the cell surface. The principal ligands for... 

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