Evidence for Differential Cortical Input to Direct Pathway versus Indirect Pathway Striatal Projection Neurons in Rats

@article{citeulike:876054, abstract = {The two main types of corticostriatal neurons are those that project only intratelencephalically (IT-type), the intrastriatal terminals of which are 0.41 {micro}m in mean diameter, and those that send their main axon into pyramidal tract and have a collateral projection to striatum (PT-type), the intrastriatal terminals of which are 0.82 {micro}m in mean diameter. We used three approaches to examine whether the two striatal projection neuron types (striatonigral direct pathway vs striatopallidal indirect pathway) differ in their input from IT-type and PT-type neurons. First, we retrogradely labeled one striatal projection neuron type or the other with biotinylated dextran amine (BDA)-3000 molecular weight. We found that terminals making asymmetric axospinous contact with striatonigral neurons were 0.43 {micro}m in mean diameter, whereas those making asymmetric axospinous contact with striatopallidal neurons were 0.69 {micro}m. Second, we preferentially immunolabeled striatonigral neurons for D1 dopamine receptors or striatopallidal neurons for D2 dopamine receptors and found that axospinous terminals had a smaller mean size (0.45 {micro}m) on D1+ spines than on D2+ spines (0.61 {micro}m). Finally, we combined selective BDA labeling of IT-type or PT-type terminals with immunolabeling for D1 or D2, and found that IT-type terminals were twice as common as PT-type on D1+ spines, whereas PT-type terminals were four times as common as IT-type on D2+ spines. These various results suggest that striatonigral neurons preferentially receive input from IT-type cortical neurons, whereas striatopallidal neurons receive greater input from PT-type cortical neurons. This differential cortical connectivity may further the roles of the direct and indirect pathways in promoting desired movements and suppressing unwanted movements, respectively. 10.1523/JNEUROSCI.1990-04.2004}, author = {Lei, Wanlong and Jiao, Yun and Del Mar, Nobel and Reiner, Anton }, citeulike-article-id = {876054}, doi = {10.1523/JNEUROSCI.1990}, journal = {J. Neurosci.}, keywords = {basalganglia, neurobiology}, month = {September}, number = {38}, pages = {8289--8299}, posted-at = {2006-09-28 08:58:54}, priority = {5}, title = {Evidence for Differential Cortical Input to Direct Pathway versus Indirect Pathway Striatal Projection Neurons in Rats}, url = {http://dx.doi.org/10.1523/JNEUROSCI.1990}, volume = {24}, year = {2004} }

TY - JOUR ID - citeulike:876054 L3 - citeulike-article-id:876054 TI - Evidence for Differential Cortical Input to Direct Pathway versus Indirect Pathway Striatal Projection Neurons in Rats JF - J. Neurosci. VL - 24 IS - 38 SP - 8289 EP - 8299 N2 - The two main types of corticostriatal neurons are those that project only intratelencephalically (IT-type), the intrastriatal terminals of which are 0.41 {micro}m in mean diameter, and those that send their main axon into pyramidal tract and have a collateral projection to striatum (PT-type), the intrastriatal terminals of which are 0.82 {micro}m in mean diameter. We used three approaches to examine whether the two striatal projection neuron types (striatonigral direct pathway vs striatopallidal indirect pathway) differ in their input from IT-type and PT-type neurons. First, we retrogradely labeled one striatal projection neuron type or the other with biotinylated dextran amine (BDA)-3000 molecular weight. We found that terminals making asymmetric axospinous contact with striatonigral neurons were 0.43 {micro}m in mean diameter, whereas those making asymmetric axospinous contact with striatopallidal neurons were 0.69 {micro}m. Second, we preferentially immunolabeled striatonigral neurons for D1 dopamine receptors or striatopallidal neurons for D2 dopamine receptors and found that axospinous terminals had a smaller mean size (0.45 {micro}m) on D1+ spines than on D2+ spines (0.61 {micro}m). Finally, we combined selective BDA labeling of IT-type or PT-type terminals with immunolabeling for D1 or D2, and found that IT-type terminals were twice as common as PT-type on D1+ spines, whereas PT-type terminals were four times as common as IT-type on D2+ spines. These various results suggest that striatonigral neurons preferentially receive input from IT-type cortical neurons, whereas striatopallidal neurons receive greater input from PT-type cortical neurons. This differential cortical connectivity may further the roles of the direct and indirect pathways in promoting desired movements and suppressing unwanted movements, respectively. 10.1523/JNEUROSCI.1990-04.2004 KW - basalganglia KW - neurobiology AU - Lei, Wanlong AU - Jiao, Yun AU - Del Mar, Nobel AU - Reiner, Anton PY - 2004/09/22/ UR - http://dx.doi.org/10.1523/JNEUROSCI.1990 ER -