Abstract
The claustrum has been the subject of intense research interest in recent years, driven in large part by its extensive connections with various regions of the cerebral cortex and by hypotheses surrounding its possible role in multimodal sensory and/or sensory–emotional integration. Here we employed neuroanatomical tracers to map projections from the claustrum–insular region to the medial prefrontal and anterior cingulate cortex of the common marmoset (Callithrx jacchus). These areas were selected based on their identification as “hub” areas of the default mode and cortical salience networks, respectively. Microinjections of fluorescent tracers, along with gold-nanoparticle-conjugated cholera toxin B-subunit and biotinylated dextran amine, were placed in subdivisions of the anterior cingulate area 24b/c and in medial prefrontal areas 32 and 32V. The resulting distribution of transported label showed rostral-caudal and dorsal-ventral topographic arrangement of claustrum connections and clear rostral-caudal topography of insular projections. Medial prefrontal connections were restricted mainly to a ventromedial strip located in the rostral half of the claustrum, with a second, smaller patch of cells in the caudal, ventrolateral portion. In contrast, injections into area 24 yielded dense, widespread connections from the dorsal claustrum, extending along its entire rostral-caudal length. Projections from the “classical” agranular, disgranular, and granular insular areas were sparse or nonexistent in areas 32 and 32V, with progressively increasing connections observed in more caudal tracer injections (i.e., in subdivisions of area 24). Transported label was observed in rostral peri-insular areas orbital periallocortex, orbital proisocortex, and insular proisocortex following all prefrontal injections. These data provide a structural connectivity foundation for interpretation of functional imaging studies, which often indicate activity in the “anterior insula” that may arise, in part, from claustrum and/or peri-insular projections to the anterior cingulate and medial prefrontal cortices.
Original language | English |
---|---|
Pages (from-to) | 1421-1441 |
Number of pages | 21 |
Journal | The Journal of Comparative Neurology |
Volume | 525 |
Issue number | 6 |
DOIs | |
Publication status | Published - 15 Apr 2017 |
Keywords
- cingulate cortex
- medial prefrontal cortex
- claustrum
- resting state networks
- marmoset
- neuroanatomy
- connections
Equipment
-
Australian Synchrotron
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility
-
Biomedical Imaging (MBI)
Gary Egan (Manager) & Kylie Reid (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility
-
Monash Micro Imaging
Stephen Firth (Manager), Alex Fulcher (Operator), Oleks Chernyavskiy (Operator), Margaret Rzeszutek (Other), David Potter (Manager), Volker Hilsenstein (Operator), Juan Nunez-Iglesias (Other), Stephen Cody (Manager), Irena Carmichael (Operator), Betty Kouskousis (Other), Sarah Creed (Manager) & Giulia Ballerin (Operator)
Faculty of Medicine Nursing and Health Sciences Research PlatformsFacility/equipment: Facility