Using complimentary methods to understand one system

The nervous system is highly organized, spatially and temporally. The DEB Lab uses several different methods to examine the relations between interoceptive structure and function, and their temporal chain of events. The architectonic examination of labeling patterns produced by several distinct histological stains enables the parcellation of brain regions (e.g., insula, cingula, thalamus, brainstem) into several distinct areas or nuclei. For example, using Evrard et al. (2014) identified 15 architectonic areas in the macaque insula. A new upcoming study from our lab also shows that the von Economo neuron (VEN) occupies only one specific architectonic area in the macaque (Horn et al., in preparation). Paxinos, Petrides and Evrard (2023) produced an exhaustive parcellation atlas of the entire rhesus monkey brain. Tract-tracing unravels the neuronal connections of specific brain regions and neurons. Krockenberger et al. (under review) showed that each of the small dysgranular subareas identified by Evrard et al. (2014) are differently connected to other parts of the brain. Evrard et al. (in preparation) confirmed that the neurons of origin of the thalamocortical projections to the “primary interoceptive cortex” of the insula are indeed located in the posterior part of the ventromedial nucleus of the thalamus (VMPo). In his seminal and highly influential studies, A.D. (Bud) Craig demonstrated that VMPo is the main target of spinal lamina 1 spinothalamic tract projection neurons (Craig, 2015). FMRI combined with sensory stimuli (e.g., cutaneous thermal stimuli), electrical microstimulation (EMS-fMRI) or optogenetics (OPTO-fMRI), or electrophysiology (ePhys-fMRI and NET-fMRI) enables the identification of functional maps that relate to interoception and to the role of specific brain regions (e.g., anterior insula) in central representations and dynamic network control. Electrophysiology (ePhys) identifies local patterns of activity in a similar experimental paradigm but with a narrow spatial focus. In our upcoming projects, we will introduce behavior and bodily physiology to begin examine how the anatomical and functional organizations of pathways studied so far under anesthesia come into play to shape behavior and regulate organ functions. Finally, neuroanatomical comparisons across species is a key endeavor in the context of evolutionary and translational hypotheses.

While based in Shanghai, the DEB Lab benefits from a unique international situation. In addition to its local members, the lab includes remote collaborating members located at the Nathan Kline Institute for Psychiatric Research (NY, USA), the Max Planck Institute for Biological Cybernetics and the Center for Integrative Neuroscience of the University of Tübingen (Germany), and the Neuro-Psychophysiology Lab at the University of Leuven (Belgium). The DEB Lab is also involved in community-based initiatives, including the Primate Data and Resource Exchange (PRIME-DRE) and the newly founded Global Primate Brain Histology Exchange (PRIME-HISTO) project.