Abstract
In rats, whisking behavior is characterized by highfrequency synchronous movements and other stereotyped patterns of bilateral coordination that are rarely seen in the bilateral movements of the limbs. This suggests that the motor systems controlling whisker and limb movements must have qualitative or quantitative differences in their interhemispheric connections. To test this hypothesis, anterograde tracing methods were used to characterize the bilateral distribution of projections from the whisker and forepaw regions in the primary motor (MI) cortex. Unilateral tracer injections in the MI whisker or forepaw regions revealed robust projections to the corresponding MI cortical area in the contralateral hemisphere. Both MI regions project bilaterally to the neostriatum, but the corticostriatal projections from the whisker region are denser and more evenly distributed across both hemispheres than those from the MI forepaw region. The MI whisker region projects bilaterally to several nuclei in the thalamus, whereas the MI forepaw region projects almost exclusively to the ipsilateral thalamus. The MI whisker region sends dense projections to the contralateral claustrum, but those to the ipsilateral claustrum are less numerous. By contrast, the MI forepaw region sends few projections to the claustrum of either hemisphere. Bilateral deposits of different tracers in MI revealed overlapping projections to the neostriatum, thalamus, and claustrum when the whisker regions were injected, but not when the forepaw regions were injected. These results suggest that the bilateral coordination of the whiskers depends, in part, on MI projections to the contralateral neostriatum, thalamus, and claustrum.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 548-564 |
| Number of pages | 17 |
| Journal | Journal of Comparative Neurology |
| Volume | 515 |
| Issue number | 5 |
| DOIs | |
| State | Published - Aug 10 2009 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Neuroscience(all)
Cite this
}
Bilateral projections from rat MI whisker cortex to the neostriatum, thalamus, and claustrum : Forebrain circuits for modulating whisking behavior. / Alloway, Kevin; Smith, Jared B.; Beauchemin, Kyle J.; Olson, Michelle L.
In: Journal of Comparative Neurology, Vol. 515, No. 5, 10.08.2009, p. 548-564.Research output: Contribution to journal › Article
TY - JOUR
T1 - Bilateral projections from rat MI whisker cortex to the neostriatum, thalamus, and claustrum
T2 - Forebrain circuits for modulating whisking behavior
AU - Alloway, Kevin
AU - Smith, Jared B.
AU - Beauchemin, Kyle J.
AU - Olson, Michelle L.
PY - 2009/8/10
Y1 - 2009/8/10
N2 - In rats, whisking behavior is characterized by highfrequency synchronous movements and other stereotyped patterns of bilateral coordination that are rarely seen in the bilateral movements of the limbs. This suggests that the motor systems controlling whisker and limb movements must have qualitative or quantitative differences in their interhemispheric connections. To test this hypothesis, anterograde tracing methods were used to characterize the bilateral distribution of projections from the whisker and forepaw regions in the primary motor (MI) cortex. Unilateral tracer injections in the MI whisker or forepaw regions revealed robust projections to the corresponding MI cortical area in the contralateral hemisphere. Both MI regions project bilaterally to the neostriatum, but the corticostriatal projections from the whisker region are denser and more evenly distributed across both hemispheres than those from the MI forepaw region. The MI whisker region projects bilaterally to several nuclei in the thalamus, whereas the MI forepaw region projects almost exclusively to the ipsilateral thalamus. The MI whisker region sends dense projections to the contralateral claustrum, but those to the ipsilateral claustrum are less numerous. By contrast, the MI forepaw region sends few projections to the claustrum of either hemisphere. Bilateral deposits of different tracers in MI revealed overlapping projections to the neostriatum, thalamus, and claustrum when the whisker regions were injected, but not when the forepaw regions were injected. These results suggest that the bilateral coordination of the whiskers depends, in part, on MI projections to the contralateral neostriatum, thalamus, and claustrum.
AB - In rats, whisking behavior is characterized by highfrequency synchronous movements and other stereotyped patterns of bilateral coordination that are rarely seen in the bilateral movements of the limbs. This suggests that the motor systems controlling whisker and limb movements must have qualitative or quantitative differences in their interhemispheric connections. To test this hypothesis, anterograde tracing methods were used to characterize the bilateral distribution of projections from the whisker and forepaw regions in the primary motor (MI) cortex. Unilateral tracer injections in the MI whisker or forepaw regions revealed robust projections to the corresponding MI cortical area in the contralateral hemisphere. Both MI regions project bilaterally to the neostriatum, but the corticostriatal projections from the whisker region are denser and more evenly distributed across both hemispheres than those from the MI forepaw region. The MI whisker region projects bilaterally to several nuclei in the thalamus, whereas the MI forepaw region projects almost exclusively to the ipsilateral thalamus. The MI whisker region sends dense projections to the contralateral claustrum, but those to the ipsilateral claustrum are less numerous. By contrast, the MI forepaw region sends few projections to the claustrum of either hemisphere. Bilateral deposits of different tracers in MI revealed overlapping projections to the neostriatum, thalamus, and claustrum when the whisker regions were injected, but not when the forepaw regions were injected. These results suggest that the bilateral coordination of the whiskers depends, in part, on MI projections to the contralateral neostriatum, thalamus, and claustrum.
UR - http://www.scopus.com/inward/record.url?scp=67650682150&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=67650682150&partnerID=8YFLogxK
U2 - 10.1002/cne.22073
DO - 10.1002/cne.22073
M3 - Article
C2 - 19479997
AN - SCOPUS:67650682150
VL - 515
SP - 548
EP - 564
JO - Journal of Comparative Neurology
JF - Journal of Comparative Neurology
SN - 0021-9967
IS - 5
ER -