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The anterior cingulate cortex (ACC) is critical for pain perception, emotion and cognition. Previous studies showed that the ACC has a complex network architecture, which can receive some projection fibers from many brain regions, including the thalamus, the cerebral cortex and other brain regions. However, there was still a lack of whole-brain mapping of the ACC in adult mice. In the present study, we utilized a rabies virus-based retrograde trans-monosynaptic tracing system to map whole-brain afferents to the unilateral ACC in adult mice. We also combined with a new high-throughput, high-speed and high-resolution VISoR imaging technique to generate a three-dimensional whole-brain reconstruction. Our results showed that several principal groups of brain structures send direct monosynaptic inputs to the ACC, including the cerebral cortex, amygdala, striatum, the thalamus, and the brainstem. We also found that cortical neurons in the ACC mainly receive ipsilateral monosynaptic projections. Some cortical areas and forebrain regions also bilaterally projected to the ACC. These findings provide a complete analysis of the afferents to the ACC in adult mice, and whole-brain mapping of ACC afferents would provide important anatomic evidence for the study of pain, memory, and cognition. [ABSTRACT FROM AUTHOR]

Corticotropin‐releasing hormone (CRH) neurons are densely distributed in the medial prefrontal cortex (mPFC), which plays a crucial role in integrating and processing emotional and cognitive inputs from other brain regions. Therefore, it is important to know the neural afferent patterns of mPFCCRH neurons, which are still unclear. Here, we utilized a rabies virus‐based monosynaptic retrograde tracing system to map the presynaptic afferents of the mPFCCRH neurons throughout the entire brain. The results show that the mPFCCRH neurons receive inputs from three main groups of brain regions: (1) the cortex, primarily the orbital cortex, somatomotor areas, and anterior cingulate cortex; (2) the thalamus, primarily the anteromedial nucleus, mediodorsal thalamic nucleus, and central medial thalamic nucleus; and (3) other brain regions, primarily the basolateral amygdala, hippocampus, and dorsal raphe nucleus. Taken together, our results are valuable for further investigations into the roles of the mPFCCRH neurons in normal and neurological disease states. These investigations can shed light on various aspects such as cognitive processing, emotional modulation, motivation, sociability, and pain. [ABSTRACT FROM AUTHOR]

The anterior cingulate cortex (ACC) is a key cortical region that plays an important role in pain perception and emotional functions. Previous studies of the ACC projections have been collected primarily from monkeys, rabbits and rats. Due to technological advances, such as gene manipulation, recent progress has been made in our understanding of the molecular and cellular mechanisms of the ACC-related chronic pain and emotion is mainly obtained from adult mice. Few anatomic studies have examined the whole-brain projections of the ACC in adult mice. In the present study, we examined the continuous axonal outputs of the ACC in the whole brain of adult male mice. We used the virus anterograde tracing technique and an ultrahigh-speed imaging method of Volumetric Imaging with Synchronized on-the-fly-scan and Readout (VISoR). We created a three-dimensional (3D) reconstruction of mouse brains. We found that the ACC projected ipsilaterally primarily to the caudate putamen (CPu), ventral thalamic nucleus, zona incerta (ZI), periaqueductal gray (PAG), superior colliculus (SC), interpolar spinal trigeminal nucleus (Sp5I), and dorsal medullary reticular nucleus (MdD). The ACC also projected to contralateral brain regions, including the ACC, reuniens thalamic nucleus (Re), PAG, Sp5I, and MdD. Our results provide a whole-brain mapping of efferent projections from the ACC in adult male mice, and these findings are critical for future studies of the molecular and synaptic mechanisms of the ACC and its related network in mouse models of brain diseases. [ABSTRACT FROM AUTHOR]

Objective We describe a novel method to spatially map interictal epileptiform discharges ( IEDs) through voxel-wise functional connectivity analysis of the functional magnetic resonance imaging (f MRI) portion of simultaneous electroencephalography ( EEG)-f MRI data. This method measures the local synchronicity of f MRI signals associated with IED and, in contrast to conventional methods, does not require modeling of neural activities or hemodynamic response. Methods Simultaneous EEG-f MRI was performed on six patients with focal epilepsy. IED events were detected from the EEG data. The f MRI data was subdivided into time segments of 20 s in length, and then reorganized into one set of concatenated time series containing the IED events and many sets without IEDs. Local degree centrality ( LDC), a metric of functional connectivity, was computed for each brain voxel to summarize its signal correlations to brain voxels within 14 mm of physical distance. This computation was repeated for each set of concatenated time series, yielding one whole-brain LDC map for time with the IED events and many maps for time without IED. A statistical score was computed for each voxel to detect the voxels with significant LDC value differences associated with IEDs. The f MRI data were also processed separately by conventional methods for comparison. Results In all six patients, regions with significant LDC increase during IEDs were concordant in location to both simultaneous EEG and the epileptogenic focus determined from separate clinical studies. In contrast, results from the conventional methods were concordant in only three patients. Significance We show that for focal epilepsy, voxel-wise functional connectivity analysis of EEG-f MRI data may improve IED localization and EEG concordance compared to the conventional analysis. This new analytic method may improve the robustness of interictal EEG-f MRI as a technique for mapping the epileptogenic focus, and helps study the local synchronization aspect of the epileptic network. [ABSTRACT FROM AUTHOR]

Summary Self-evaluation of one’s own ignorance requires us to peer into our own mind retrospectively. Here, we found that only the bilateral frontopolar cortices (area 10) are recruited for metacognitive evaluation of non-experienced events in macaque monkeys performing metacognitive confidence judgment on memory under fMRI scanning and that targeted reversible inactivation of the localized spots in area 10 selectively impaired the confidence judgment of non-experienced events. In contrast, fMRI experiments revealed that area 10 was not recruited for metacognition of experienced events like the way that the dorsal prefrontal cortex (area 9) was and, correspondingly, the inactivation of area 10 did not impair confidence judgment of experienced events. Notably, this inactivation did not impair the ability to identify novel events by distinguishing from repetitive events. Our findings elucidate that the frontopolar cortex plays a causal role to confer not awareness of past experience in general but awareness of one’s own ignorance. [ABSTRACT FROM AUTHOR]

Summary Assigning behavioral functions to neural structures has long been a central goal in neuroscience and is a necessary first step toward a circuit-level understanding of how the brain generates behavior. Here, we map the neural substrates of locomotion and social behaviors for Drosophila melanogaster using automated machine-vision and machine-learning techniques. From videos of 400,000 flies, we quantified the behavioral effects of activating 2,204 genetically targeted populations of neurons. We combined a novel quantification of anatomy with our behavioral analysis to create brain-behavior correlation maps, which are shared as browsable web pages and interactive software. Based on these maps, we generated hypotheses of regions of the brain causally related to sensory processing, locomotor control, courtship, aggression, and sleep. Our maps directly specify genetic tools to target these regions, which we used to identify a small population of neurons with a role in the control of walking. [ABSTRACT FROM AUTHOR]