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. J. Comp. Neurol. 525:1421-1441, 2017. © 2016 Wiley Periodicals, Inc.

There has been a surge of interest in the structure and function of the mammalian claustrum in recent years. However, most anatomical and physiological studies treat the claustrum as a relatively homogenous structure. Relatively little attention has been directed toward possible compartmentalization of the claustrum complex into anatomical subdivisions, and how this compartmentalization is reflected in claustrum connections with other brain structures. In this study, we examined the cyto- and myelo-architecture of the claustrum of the common marmoset (Callithrix jacchus), to determine whether the claustrum contains internal anatomical structures or compartments, which could facilitate studies focused on understanding its role in brain function. NeuN, Nissl, calbindin, parvalbumin, and myelin-stained sections from eight adult marmosets were studied using light microscopy and serial reconstruction to identify potential internal compartments. Ultra high resolution (9.4T) post-mortem magnetic resonance imaging was employed to identify tractographic differences between identified claustrum subcompartments by diffusion-weighted tractography. Our results indicate that the classically defined marmoset claustrum includes at least two major subdivisions, which correspond to the dorsal endopiriform and insular claustrum nuclei, as described in other species, and that the dorsal endopiriform nucleus (DEnD) contains architecturally distinct compartments. Furthermore, the dorsal subdivision of the DEnD is tractographically distinguishable from the insular claustrum with respect to cortical connections.

Despite the importance of transition metals for normal brain function, relatively little is known about the distribution of these elemental species across the different tissue compartments of the primate brain. In this study, we employed laser ablation-inductively coupled plasma-mass spectrometry on PFA-fixed brain sections obtained from two adult common marmosets. Concurrent cytoarchitectonic, myeloarchitectonic, and chemoarchitectonic measurements allowed for identification of the major neocortical, archaecortical, and subcortical divisions of the brain, and precise localisation of iron, manganese, and zinc concentrations within each division. Major findings across tissue compartments included: (1) differentiation of white matter tracts from grey matter based on manganese and zinc distribution; (2) high iron concentrations in the basal ganglia, cortex, and substantia nigra; (3) co-localization of high concentrations of iron and manganese in the primary sensory areas of the cerebral cortex; and (4) high manganese in the hippocampus. The marmoset has become a model species of choice for connectomic, aging, and transgenic studies in primates, and the application of metallomics to these disciplines has the potential to yield high translational and basic science value.

Assessment is an important component of the occupational therapy process. This article details the development of an observation form that can be used to assess a patient's performance during occupational therapy treatment. The form acts as a continuous assessment record with the aim of evaluating a patient's performance over a period of time.