the dopamine d2 receptor gene in lamprey, its expression in the striatum and cellular effects of d2 receptor activation七鳃鳗的多巴胺d2受体基因,其表达d2受体激活纹状体和细胞的影响.pdf

The Dopamine D2 Receptor Gene in Lamprey, Its Expression in the Striatum and Cellular Effects of D2 Receptor Activation 1 2 1 1 ´ Brita Robertson , Icnelia Huerta-Ocampo , Jesper Ericsson , Marcus Stephenson-Jones , Juan Perez- ´ 3 2 1 1 Fernandez , J. Paul Bolam , Rochellys Diaz-Heijtz , Sten Grillner * 1 Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden, 2 MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, Oxford, United Kingdom, 3 Neurolam Group, Department of Functional Biology and Health Sciences, Faculty of Biology, University of Vigo, Vigo, Spain Abstract All basal ganglia subnuclei have recently been identified in lampreys, the phylogenetically oldest group of vertebrates. Furthermore, the interconnectivity of these nuclei is similar to mammals and tyrosine hydroxylase-positive (dopaminergic) fibers have been detected within the input layer, the striatum. Striatal processing is critically dependent on the interplay with the dopamine system, and we explore here whether D2 receptors are expressed in the lamprey striatum and their potential role. We have identified a cDNA encoding the dopamine D2 receptor from the lamprey brain and the deduced protein sequence showed close phylogenetic relationship with other vertebrate D2 receptors, and an almost 100% identity within the transmembrane domains containing the amino acids essential for dopamine binding. There was a strong and distinct expression of D2 receptor mRNA in a subpopulation of striatal neurons, and in the same region tyrosine hydroxylase-immunoreactive syn