Cholinergic Modulation of the Default Mode Like Network in Rats.

The discovery of the default mode network (DMN), a large-scale brain network that is suppressed during attention-demanding tasks, had major impact in neuroscience. This network exhibits an antagonistic relationship with attention-related networks. A better understanding of the processes underlying modulation of DMN is imperative, as this network is compromised in several neurological diseases.

Chemogenetic silencing of neurons in the mouse anterior cingulate area modulates neuronal activity and functional connectivity.

The anterior cingulate area (ACC) is an integral part of the prefrontal cortex in mice and supports cognitive functions, including attentional processes, motion planning and execution as well as remote memory, fear and pain. Previous anatomical and functional imaging studies demonstrated that the ACC is interconnected with numerous brain regions, such as motor and sensory cortices, amygdala and limbic areas, suggesting it serves as a hub in functional networks. However, the exact role of the ACC in regulating functional network activity and connectivity remains to be elucidated.

Combining designer receptors exclusively activated by designer drugs and neuroimaging in experimental models: A powerful approach towards neurotheranostic applications.

The combination of chemogenetics targeting specific brain cell populations with in vivo imaging techniques provides scientists with a powerful new tool to study functional neural networks at the whole-brain scale. A number of recent studies indicate the potential of this approach to increase our understanding of brain function in health and disease. In this review, we discuss the employment of a specific chemogenetic tool, designer receptors exclusively activated by designer drugs, in conjunction with non-invasive neuroimaging techniques such as PET and MRI.

Bottom-up sensory processing can induce negative BOLD responses and reduce functional connectivity in nodes of the default mode-like network in rats.

The default mode network is a large-scale brain network that is active during rest and internally focused states and deactivates as well as desynchronizes during externally oriented (top-down) attention demanding cognitive tasks. However, it is not sufficiently understood if salient stimuli, able to trigger bottom-up attentional processes, could also result in similar reduction of activity and functional connectivity in the DMN. In this study, we investigated whether bottom-up sensory processing could influence the default mode-like network (DMLN) in rats.

Decreased levels of active uPA and KLK8 assessed by [ In]MICA-401 binding correlate with the seizure burden in an animal model of temporal lobe epilepsy.

Objective: Urokinase-type plasminogen activator (uPA) and kallikrein-related peptidase 8 (KLK8) are serine proteases that contribute to extracellular matrix (ECM) remodeling after brain injury. They can be labelled with the novel radiotracer [ In]MICA-401. As the first step in exploring the applicability of [ In]MICA-401 in tracing the mechanisms of postinjury ECM reorganization in vivo, we performed in vitro and ex vivo studies, assessing [ In]MICA-401 distribution in the brain in two animal models: kainic acid-induced status epilepticus (KASE) and controlled cortical impact (CCI)-induced traumatic brain injury (TBI).