Synaptic association of dopaminergic axon terminals and neurokinin-1 receptor-expressing intrinsic neurons in the striatum of the rat.
We examined if axon terminals of dopaminergic neurons might make synapses upon neurokinin-1 receptor (NK1R)-expressing intrinsic neurons in the rat striatum. In a double-immunocytochemical ultrastructural study, dopaminergic terminals were labeled by the immunoperoxidase method for tyrosine hydroxylase (TH), while NK1R-immunoreactivity (-IR) was revealed by the immunogold-silver labeling method. Some TH-immunoreactive (-ir) axon terminals formed synapses of the symmetric or intermediate type on NK1R-ir neuronal profiles; usually on dendritic profiles and rarely on somatic profiles. It was further confirmed by means of triple-immunofluorescence histochemistry that NK1R-ir neurons in close association with TH-ir axon terminals showed nitric oxide synthase (NOS)- or vesicular acetylcholine transporter-IR. Since NK1R-expressing striatal neurons are segregated into cholinergic and somatostatin/NOS-containing intrinsic neurons (Brain Res. 631 (1993) 297; Neurosci. Lett. 310 (2001) 109), the present results indicate that dopaminergic neurons make synapses upon these intrinsic neurons in the striatum.
Li
Jin-Lian
JL
Department of Anatomy and K.K. Leung Brain Research Center, The Fourth Military Medical University, Xi'an 710032, People's Republic of China.
Kaneko
Takeshi
T
Mizuno
Noboru
N
D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D007150:Immunohistochemistry; D007395:Interneurons / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D026901:Membrane Transport Proteins; D008854:Microscopy, Electron; D017072:Neostriatum / Q000378:metabolism* / Q000648:ultrastructure; D009434:Neural Pathways / Q000378:metabolism* / Q000648:ultrastructure; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D018040:Receptors, Neurokinin-1 / Q000378:metabolism* / Q000648:ultrastructure; D013004:Somatostatin / Q000378:metabolism; D013373:Substance P / Q000378:metabolism; D013378:Substantia Nigra / Q000378:metabolism* / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000502:physiology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D018040:Receptors, Neurokinin-1; C493461:Slc18a3 protein, rat; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins; D009569:Nitric Oxide; D013373:Substance P; D013004:Somatostatin; D019001:Nitric Oxide Synthase; D014446:Tyrosine 3-Monooxygenase; D000109:Acetylcholine; D004298:Dopamine