Receptor subtypes,multiplicity expression

Hirst WD, Cheung NY, Rattray M, Price GW, Wilkin GP. Cultured astrocytes express messenger RNA for multiple serotonin receptor subtypes, without functional coupling of 5-1I I, receptor subtypes to adenylyl cyclase. Brain Res Mol Brain Res 1998 61 90-99. 

Dixit VD, Schaffer EM, Pyle RS, CoUins GD, Sakthivel SK, Palaniappan R, I.illaid JW, Taub DD (2004) Ghrelin inhibits leptin- and activation-induced proinflammatory cytokine expression by human monocytes and T cells. J CUn Invest 114 57-66 Dmitrieva N, Shelton D, Rice ASC, McMahon SB (1997) The role of nerve growth factor in a model of visceral inflammation. Neuroscience 78 449-459 Doak GJ, Sawynok J (1997) Formalin-induced nodceptive behavior and edema involvement of multiple peripheral 5-hydroxytryptamine receptor subtypes. Neuroscience 80 939-949 Dobner PR (2006) Neurotensin and pain modulation. Peptides 27 2405-2414 Dobolyi A, Ueda H, Uchida H, Palkovits M, Usdin TB (2002) Anatomical and physiological evidence for involvement of tuberoinfundibular peptide of 39 residues in nociception. Proc Natl Acad Sci U S A 99 1651-1656... 

Cotecchia S, Kobilka BK, Daniel KW, et al. Multiple 2nd messenger pathways of a-adrenergic receptor subtypes expressed in eukaryotic cells. J Biol Chem 1990 265 63-69. 

Eason MG, Liggett SB. Human a2-adrenergic receptor subtype distribution widespread and subtype-selective expression of a2C10, a2C4, and a2C2 mRNA in multiple tissues. Mol Pharmacol 1993 44 70-75. 

McCune SK, Voigt MM, Hill JM. Expression of multiple a-adrenergic receptor subtype messenger RNAs in the adult rat brain. Neuroscience 1993 57 143-151. 

The existence of multiple o AR subtypes coupled to multiple second messenger systems and co-expressed in a variety of tissues complicates studies aimed at defining the role of each receptor subtype. Expression of the cloned subtypes and the development of subtype selective compounds will help to evaluate the function of this class of receptors. 

As described above, regulation of the relative activity in striatopallidal and striatonigral neurons may be effected through the direct actions of dopamine on receptor subtypes that are differentially expressed by these two output neuron populations. However, there are multiple other neurotransmitter/receptor systems that may also function to regulate the activity of these neurons. At this time the multiplicity of interactions that presumably occur during the normal functioning of the striatum have not been worked out in any detail. Some plausible cellular interactions may be suggested based on both neu-roanatomical and receptor localization studies. 

Most neurons and glia in the mammalian central nervous system express multiple receptor subtypes activated by L-Glutamic acid (l-G1u, 1). These receptors have been classified into two main families, termed ionotropic glutamate (iGlu) receptors and metabotropic glutamate (mGlu) receptors (Fig. 1). 

Several lines of evidence suggest that multiple intracellular receptor domains (particularly the cytoplasmic loop between transmembrane segment III-IV and V-VI) are involved in G-protein coupling. In order to delineate receptor domains responsible for the G-protein coupling selectivity displayed by the individual muscarinic receptor subtypes, chimeric ml/m2 and m2/m3 muscarinic receptors have been constmcted and functionally characterized in different expression systems. Biochemical and electro-... 

---