A direct projection from the subthalamic nucleus to the ventral thalamus in monkeys.
The current basal ganglia model considers the internal division of the globus pallidus and the substantia nigra pars reticulata as the sole sources of basal ganglia output to the thalamus. However, following the delivery of retrograde tracers into the ventral anterior/ventral lateral thalamic nuclei, a moderate number of labeled neurons were found within the subthalamic nucleus (STN) in control cases, MPTP-treated monkeys and animals with levodopa-induced dyskinesias. Furthermore, dual tracing experiments showed that subthalamo-thalamic and subthalamo-pallidal projections arise from different subpopulations of STN efferent neurons. Moreover, upregulated expression of the mRNA coding the vesicular glutamate transporter 2 (vGlut2) was found in retrogradely-labeled STN neurons in MPTP-treated monkeys. By contrast, there is a reduction in vGlut2 mRNA expression in subthalamo-thalamic neurons in dyskinetic monkeys. In conclusion, our findings support the presence of a direct projection from the STN to the ventral thalamus that appears to be functionally modulated by dopaminergic activity.
Rico
Alberto J
AJ
Area de Neurociencias, Centro de Investigación Médica Aplicada (CIMA), Facultad de Medicina, Universidad de Navarra, Pamplona, Spain.
Barroso-Chinea
Pedro
P
Conte-Perales
Lorena
L
Roda
Elvira
E
Gómez-Bautista
Virginia
V
Gendive
Miriam
M
Obeso
José A
JA
Lanciego
José L
JL
D000818:Animals; D008252:Macaca fascicularis / Q000502:physiology*; D008297:Male; D018613:Microscopy, Confocal; D009434:Neural Pathways / Q000502:physiology; D056325:Neuronal Tract-Tracers; D009474:Neurons / Q000378:metabolism; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000503:physiopathology*; D020531:Subthalamic Nucleus / Q000502:physiology*; D020651:Ventral Thalamic Nuclei / Q000502:physiology*; D050599:Vesicular Glutamate Transport Protein 2 / Q000378:metabolism
D056325:Neuronal Tract-Tracers; D050599:Vesicular Glutamate Transport Protein 2