Motor behavior results in complex exchanges of motor and sensory information across cortical regions. Therefore, fully understanding the cerebral cortex’s role in motor behavior requires a mesoscopic-level description of the cortical regions engaged, their functional interactions, and how these functional interactions change with behavioral state. Mesoscopic Ca2+ imaging through transparent polymer skulls in mice reveals elevated activation of the dorsal cerebral cortex during locomotion. Using the correlations between the time series of Ca2+ fluorescence from 28 regions (nodes) obtained using spatial independent component analysis (sICA), we examined the changes in functional connectivity of the cortex from rest to locomotion with a goal of understanding the changes to the cortical functional state that facilitate locomotion. Both the transitions from rest to locomotion and from locomotion to rest show marked increases in correlation among most nodes. However, once a steady state of continued locomotion is reached, many nodes, including primary motor and somatosensory nodes, show decreases in correlations, while retrosplenial and the most anterior nodes of the secondary motor cortex show increases. These results highlight the changes in functional connectivity in the cerebral cortex, representing a series of changes in the cortical state from rest to locomotion and on return to rest.

Cell death is desirable in cancer cells and undesirable in organs with limited regenerative potential, like the heart. Cell death comes in many forms, but only apoptosis and to a lesser degree necrosis is currently relevant to the clinical imager. Noninvasive imaging of cell death is an attractive option to understand pathophysiology, track disease activity, and evaluate response to intervention. Apoptosis seems to be the most promising target for imaging cell death, because it could be reversible and might be modulated with interventions. Molecular, nuclear, optical, or magnetic resonance imaging-based methods have been developed to identify intermediate steps in the apoptosis cascade. Animal studies show promising results for noninvasive imaging in various cardiovascular diseases. Human studies have shown feasibility, but clinical use is yet inconclusive. Newer technologies offer promise, especially for tracking apoptosis in evaluation of novel therapeutic interventions.

Duramycin is similarly effective in imaging apoptotic cell death as Annexin-V with lower nontarget organ radiation. Clinical feasibility of apoptosis imaging with a PE-seeking tracer should be tested.

No abstract

No abstract