Neurotransmitter receptors plasticity

A. J. Pocklington, M. Cumiskey, J. D. Armstrong, and S. G. N. Grant. 2006, The Proteomes of Neurotransmitter Receptor Complexes from Modular Networks with Distributed Functionality Underlying Plasticity and Behaviour, www.molecularsystemsbiology.com—Article nr 2006.0023. 

Plasticity is also evident at the level of the neurotransmitter receptors. These are fluid structures that can be internalized into the membrane so that their density, and affinity for a transmitter, on the outer surface of the nerve membrane may change according to functional need. 

Receptor plasticity could be invoked as the underlying common trait of multiple receptors. For example, although the multiple adrenergic isoreceptors are similar, they react to the common neurotransmitter norepinephrine (2.4) in a quantitatively different manner. They also show a drug specificity that varies from organ to organ and differs in various species of animals. In subsequent chapters of this book, receptor multiplicity as the rule rather than the exception will become amply evident. It is to be hoped that, in time, the comparison of isoreceptor molecular structures will provide precise criteria for their differentiation. 

Besides their activity mediated by neurotransmitter receptors, clavine alkaloids also possess antibiotic and cytostatic activities. The antibiotic activity of EA was ascribed to inhibition of nucleic acid replicatory processes [32]. The antineo-plastic and antiviral activity of various heterocycles could be augmented by their N-ribosylation. The preparation of N-ribosides of EA could form analogous compounds to nucleosides with the aglycon possessing both neuro-humoral and cytostatic activity. 

Trk receptor cell surface proteins that are involved in transducing the actions of neurotrophins to promote neuronal survival, proliferation, migration, axonal and dendritic outgrowth and patterning, synapse strength and plasticity, injury protection, as well as controlling the activity of ion channels and neurotransmitter receptors. 

Thus the neurotransmitter role of ATP is well established in the periphary and also in sensory systems but its importance in the CNS remains to be elucidated (see Burnstock 1996). That requires the development of more specific antagonists and methods of mapping its location. The strong linkage of its P2x receptors to calcium currents may also provide a role for ATP in more long-term effects such as plasticity and neuronal development and death. 

V-methyl-D-aspartate receptors. Glutamate is the major excitatory neurotransmitter in the central nervous system (Ch. 15). Its receptors can be divided into three types AMPA/kainate, NMDA and metabotropic receptors. NMDA receptors are composed of two different types of subunit - NR1 and NR2. They play an important role in the induction of synaptic plasticity and excitotoxicity. 

AA metabolites and PAF have initially been studied in terms of their roles in the inflammatory response, such as increased vascular permeability and the activation of and infiltration by inflammatory cells. It is now becoming apparent, however, that these bioactive lipids have significant neurobiological actions in ion channel functions, receptors, neurotransmitter release, synaptic plasticity and neuronal gene expression. 

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