Skip to main content

Advertisement

Log in

Anatomical substrates for direct interactions between hippocampus, medial prefrontal cortex, and the thalamic nucleus reuniens

  • Original Article
  • Published:
Brain Structure and Function Aims and scope Submit manuscript

Abstract

The reuniens nucleus in the midline thalamus projects to the medial prefrontal cortex (mPFC) and the hippocampus, and has been suggested to modulate interactions between these regions, such as spindle–ripple correlations during sleep and theta band coherence during exploratory behavior. Feedback from the hippocampus to the nucleus reuniens has received less attention but has the potential to influence thalamocortical networks as a function of hippocampal activation. We used the retrograde tracer cholera toxin B conjugated to two fluorophores to study thalamic projections to the dorsal and ventral hippocampus and to the prelimbic and infralimbic subregions of mPFC. We also examined the feedback connections from the hippocampus to reuniens. The goal was to evaluate the anatomical basis for direct coordination between reuniens, mPFC, and hippocampus by looking for double-labeled cells in reuniens and hippocampus. In confirmation of previous reports, the nucleus reuniens was the origin of most thalamic afferents to the dorsal hippocampus, whereas both reuniens and the lateral dorsal nucleus projected to ventral hippocampus. Feedback from hippocampus to reuniens originated primarily in the dorsal and ventral subiculum. Thalamic cells with collaterals to mPFC and hippocampus were found in reuniens, across its anteroposterior axis, and represented, on average, about 8 % of the labeled cells in reuniens. Hippocampal cells with collaterals to mPFC and reuniens were less common (~1 % of the labeled subicular cells), and located in the molecular layer of the subiculum. The results indicate that a subset of reuniens cells can directly coordinate activity in mPFC and hippocampus. Cells with collaterals in the hippocampus–reuniens–mPFC network may be important for the systems consolidation of memory traces and for theta synchronization during exploratory behavior.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

Download references

Acknowledgments

We thank K. Rockland for advice and comments throughout the duration of the project and for feedback on the manuscript. We also thank MJ. Galazo and J. Castro for technical advice and the M. Sur and S. Tonegawa laboratories for access to confocal and epifluorescence microscopes. This work was supported by a postdoctoral fellowship from the Caja Madrid Foundation (C.V.) and US National Institutes of Health grant 5R01MH061976 (M.A.W.).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to C. Varela.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (EPS 413910 kb)

Supplementary material 2 (EPS 2085 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Varela, C., Kumar, S., Yang, J.Y. et al. Anatomical substrates for direct interactions between hippocampus, medial prefrontal cortex, and the thalamic nucleus reuniens. Brain Struct Funct 219, 911–929 (2014). https://doi.org/10.1007/s00429-013-0543-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00429-013-0543-5

Keywords

Navigation