Biology subjects

Aronson, J.

Publications and source records attributed to Aronson, J..

3 recordsLinked to original sources

bioRxiv2020

Wide-Field Calcium Imaging of Dynamic Cortical Networks During Locomotion

Motor behavior results in widespread activation of the cerebral cortex. Therefore, fully understanding the cerebral cortexs role in motor behavior requires a mesoscopic level description of the engaged cortical regions and their functional interactions. Mesoscopic imaging of Ca2+ fluorescence through transparent polymer skulls implanted on transgenic Thy1-GCaMP6f mice reveals widespread activation of the cerebral cortex during locomotion, including not only in primary motor and somatosensory regions but also in secondary motor, retrosplenial, and visual cortices. Using the time series of Ca2+ fluorescence from 28 regions (nodes) we found to be consistent across mice, we examined the changes in functional connectivity from rest to locomotion. At the initiation of locomotion, the most anterior nodes of the secondary motor cortex increase in correlation with other nodes, while other nodes decrease in correlation. Eigenvector centrality confirms these changes in functional connectivity. Directed Granger causality analysis reveals an increase in causal influence of anterior regions of secondary motor cortex on other dorsal cortical regions at the onset of locomotion. These results highlight the global changes in correlation, centrality, and causality occurring throughout the cerebral cortex between rest and locomotion and suggest that the premotor areas play an important role in organizing these changes.

neuroscience↗

bioRxiv2019

Combined use of metagenomic sequencing and host response profiling for the diagnosis of suspected sepsis.

BackgroundCurrent diagnostic techniques are inadequate for rapid microbial diagnosis and optimal management of patients with suspected sepsis. We assessed the clinical impact of three powerful molecular diagnostic methods. MethodsWith blood samples from 200 consecutive patients with suspected sepsis, we evaluated 1) metagenomic shotgun sequencing together with a Bayesian inference approach for contaminant sequence removal, for detecting bacterial DNA; 2) viral capture sequencing; and 3) transcript-based host response profiling for classifying patients as infected or not, and if infected, with bacteria or viruses. We then evaluated changes in diagnostic decision-making among three expert physicians by unblinding the results of these methods in a staged fashion. ResultsMetagenomic shotgun sequencing confirmed positive blood culture results in 14 of 26 patients. In 17 of 200 patients, metagenomic sequencing and viral capture sequencing revealed organisms that were 1) not detected by conventional hospital tests within 5 days after presentation, and 2) classified as of probable clinical relevance by physician consensus. Host response profiling led at least two of three physicians to change their diagnostic decisions in 46 of 100 patients. The data suggested possible bacterial DNA translocation in 8 patients who were originally classified by physicians as noninfected and illustrate how host response profiling can guide interpretation of metagenomic shotgun sequencing results. ConclusionsThe integration of host response profiling, metagenomic shotgun sequencing, and viral capture sequencing enhances the utility of each, and may improve the diagnosis and management of patients with suspected sepsis.

microbiology↗

bioRxiv2019

Modulation of emotion perception and memory via sub-threshold amygdala stimulation in humans

A common human experience is noticing that emotional life events are more vividly remembered than dull ones. Studies show that the amygdala plays a central role in such emotionally driven enhancement of memory. With this in mind, we investigated the effect of electrical brain stimulation of the left human amygdala on performance on an emotional perception and emotional memory task. We randomly applied sub-threshold 50 Hz stimulation to the left amygdala in 10 patients (5 female and 5 male) with intracranial electrodes during the encoding portion of an emotional valence perception and emotional memory task. We found that amygdala stimulation did not affect reported valence for neutral stimuli (non-stimulated group average valence 5.34, stimulated 5.38, p=0.68) but it did affect positively (non-stimulated group average valence 7.31, stimulated 6.70, p=0.004) and negatively (non-stimulated group average valence 2.79, stimulated 3.55, p=0.0002) valenced stimuli in effect reporting both valence categories as more neutral. Furthermore, we found that stimulation did not significantly disrupt memory for neutral stimuli (68% vs. 61% correctly remembered p=0.48) or positive stimuli (87% vs. 70% correct, trend towards significant difference p=0.09) but did for negative stimuli (83% vs. 67% correct, p=0.03). These results suggest that electrical brain stimulation by our parameters likely reversibly inhibits amygdala function disrupting neural networks responsible for emotional perception and memory. This effect may have clinical implications in treatment of certain neuropsychiatric disorders, such as emotional dysregulation and post-traumatic stress disorder.\n\nStatement of significanceThe current study builds and expands on extensive prior research into the function of the human amygdala. It provides the first systematic description in humans of a cognitive change brought about by direct electrical stimulation of the amygdala on perception of emotional valence and emotional memory. The results provide further evidence on the importance of the amygdala in human cognition. Likewise, out method utilized to study the function of the amygdala can be extended to study the function of other brain regions in humans, such as the cingulate. While these results are preliminary and need to be duplicated, we aim to further study the effects of amygdala stimulation on emotional processing including possible therapeutic application for diverse group of neuropsychiatric conditions.

neuroscience↗