The co-expressing D1–D2 neurons in the striatum of the common tree shrew (Tupaia glis)
Keywords:
striatum, D1 neuron, substance P, D2 neuron, tree shrewAbstract
Abstract The striatum contains D1 and D2 neurons within the striosome and matrix regions. The objective of this study was to identify the distribution of D1 and D2 striatal neurons in tree shrews by fluorescent immunohistochemistry using D1, D2 and substance P antibodies. Animal brain sections were immunolabeled with antibodies against the D1 receptor and substance P and then counterstained for nuclei with DAPI. It was revealed that 91% of D1 labeled neurons in the striatum were in close contact with substance P labeled terminals. Thus, substance P antibody was used as a marker for D1 neurons. Brain sections were incubated with antibodies against substance P and D2 receptors and then counterstained for nuclei with DAPI. The results showed that 88% of total neurons were in cotse contact with substance P labeled terminals in the striosome and 30% were D2 labeled neurons that were in contact with substance P labeld terminals. The matrix contained 98% of D2 labeled neurons, and 29% of D2 labeled neurons that were in close contact with substance P labeled terminals. In conclusion, approximately 30 % of striatal neurons in either the striosome or matrix expressed both D1 and D2 receptors. These co-expressing D1-D2 neurons probably send different outputs from those of D1 or D2 neurons.
References
Graybiel AM. Building action repertoires: memory and learning functions of the basal ganglia. Curr Opin Neurobiol. 1995;5:733-41.
Seema MV. Fourty-fi ve years of schizophrenia: per-sonal refl ection. Hist Psychiatry. 2006;67:363-73.
Toda M, Abi-Dargham A. Dopamine hypothesis of schizophrenia: making sense of it all. Curr Psy-chiatry Rep. 2007;9:329-36.
Gerfen C. Synaptic organization of the striatum. J Electron Microsc Tech. 1988;10:265-81.
Goldman-Rakic PS. Cytoarchitectonic heteroge-neity of the primate neostriatum: Subdivision into island and matrix cellular compartments. J Comp Neurol. 1982;205:398-413.
Day-Brown J, Wei H, Chomsung R, Petry H, Bick-ford ME. 2010. Pulvinar projections to the striatum and amygdala in the tree shrew. Front Neuroanat. 2010;15:143. doi: 10.3389/fnana.2010.00143.
Rice MW, Roberts RC, Melendez-Ferro M, Perez-Costas E. Neurochemical characterization of the tree shrew dorsal striatum. Front Neuroanat. 2011; 5:1-17.
Bolam J, Izzo P. The postsynaptic targets of sub-stance P-immunoreactive terminals in the rat ne-ostriatum with particular reference to identifi ed spiny striatonigral neurons. Exp Brain Res. 1988; 70:361-77.
Reinius B, Blunder M, Brett FM, Eriksson A, Patra K, Jonsson J, et al. Conditional targeting of me-dium spiny neurons in the striatal matrix. Front Be-hav Neurosc. 2015;9:71. doi: 10.3389/fnbeh.2015. 00071.
Seeharach K, Days-Brown J, Tocharus C, Bick-ford ME, Quiggins R. Synaptic organization of do-pamine input in striatum of tree shrew, Tupaia glis Proceedings of the anatomy association Thailand 35th AAT Annual Conference. 2012; 98.
Feqer J, Crossman A. Identifi cation of different subpopulations of neostriatal neurons projecting to globus pallidus or substantia nigra in the mon-key: a retrograde fl uorescence double-labeling study. Neurosci Lett. 1984;49:7-12.
Wang H, Deng YP, Reiner A. In situ hybridization histochemical and immunohistochemical evidence that striatal projection neurons co-containing sub-stance P and enkephalin are overrepresented in the striosomal compartment of striatum in rats. Neurosci Lett. 2007;425:195-9.
Deng, YP, Lei WL, Reiner A. Differential perikaryal localization in rats of D1 and D2 dopamine recep-tors on striatal projection neuron types identifi ed by retrograde labeling. J Chem Neuroanat. 2006; 32:101-16.
Surmeier DJ, Ding J, Day M, Wang Z, Shen W. D1 and D2 dopamine-receptor modulation of striatal glutamatergic signaling in striatal medium spiny neurons. Trends Neurosci 2007;30:228-35.
