Connections of the subthalamic nucleus with ventral striatopallidal parts of the basal ganglia in the rat
Article first published online: 9 OCT 2004
Copyright © 1990 Wiley-Liss, Inc.
Journal of Comparative Neurology
Volume 294, Issue 4, pages 607–622, 22 April 1990
How to Cite
Groenewegen, H. J. and Berendse, H. W. (1990), Connections of the subthalamic nucleus with ventral striatopallidal parts of the basal ganglia in the rat. J. Comp. Neurol., 294: 607–622. doi: 10.1002/cne.902940408
- Issue published online: 9 OCT 2004
- Article first published online: 9 OCT 2004
- Manuscript Accepted: 6 DEC 1989
- ventral pallidum;
- substantia nigra;
- midbrain extrapyramidal area;
- lateral hypothalamus;
- Phaseolus vulgaris-leucoagglutinin (PHA-L);
- Fluoro-Gold (FG);
- cholera toxin B (CTb)
The present study was undertaken to establish the precise anatomical relationship of the subthalamic nucleus (STh) with limbic lobe-afferented parts of the basal ganglia in the rat. The anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHA-L), injected in the STh, the globus pallidus, the ventral pallidum, the ventral striatum, and the parafascicular thalamic nucleus, and the retrograde tracers Fluoro-Gold (FG) and cholera toxin B (CTb), injected in the globus pallidus, the ventral pallidum, the ventral striatum, and the ventral mesencephalon, were used for this purpose. The results of these tracing experiments confirm the general notion of reciprocal connections between the STh and pallidal areas. Thus the dorsomedial part of the STh is connected with the subcommisural ventral pallidum, whereas a more ventral and lateral part of the medial STh is related to the medial globus pallidus. The lateral hypothalamic area, directly adjacent to the STh, containing neurons with a morphology quite similar to those in the STh, projects to parts of the ventral pallidum related to the olfactory tubercle. The reciprocal projection from this pallidal area to subthalamic regions appears to be very sparse. The medial STh sends strong projections to the medial part of the entopeduncular nucleus and the adjacent lateral hypothalamic area. Sparser projections from the medial STh reach the rostral and medial part of the caudate-putamen and the nucleus accumbens. The nucleus accumbens. The nucleus accumbens sends a very sparse projection back to the medial STh. The projections of the medial STh to the ventral mesencephalon appear also to be topographically organized. The lateral hypothalamus and a few cells in the most medial part of the STh project to the ventral tegmental area, whereas progressively more lateral parts of the ventral mesencephalon, in particular the substantia nigra, receive input from successively more lateral and caudal parts of the STh. In addition, a number of STh fibers reach the midbrain extrapyramidal area. The lateral part of the parafascicular thalamic nucleus projects to the lateral part of the STh, whereas parafascicular neurons medial to the fasciculus retroflexus projects to the dorsomedial portion of the STh.
The medial part of the STh and the adjacent lateral hypothalamus are intimately connected with limbic parts of the basal ganglia in a way similar and parallel to the connections of the lateral STh with motor-related parts of the basal ganglia. These findings suggest a role for the STh in nonmotor functions of the basal ganglia.