Firing rate dependence of "truncation thresholds"

Author(s):  
Murat Okatan ◽  
Mehmet Kocaturk
Keyword(s):  
2016 ◽  
Vol 115 (2) ◽  
pp. 625-627 ◽  
Author(s):  
Alex I. Wiesman

Although the importance of gamma oscillatory activity in brain function is well established, the exact contributions of neuron and synapse type remains unclear. In their study, Hu and Agmon ( J Neurophysiol 114: 624–637, 2015) show that precision as well as firing rate dependence of gamma synchrony rely primarily on cellular coupling type (chemical, electrical, or dual), rather than properties intrinsic to cell type. These findings are discussed with a focus on current ramifications and the implications for future research.


Author(s):  
Fernando V. Stump ◽  
Nikhil Karanjgaokar ◽  
Philippe H. Geubelle ◽  
Ioannis Chasiotis

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Eslam Mounier ◽  
Bassem Abdullah ◽  
Hani Mahdi ◽  
Seif Eldawlatly

AbstractThe Lateral Geniculate Nucleus (LGN) represents one of the major processing sites along the visual pathway. Despite its crucial role in processing visual information and its utility as one target for recently developed visual prostheses, it is much less studied compared to the retina and the visual cortex. In this paper, we introduce a deep learning encoder to predict LGN neuronal firing in response to different visual stimulation patterns. The encoder comprises a deep Convolutional Neural Network (CNN) that incorporates visual stimulus spatiotemporal representation in addition to LGN neuronal firing history to predict the response of LGN neurons. Extracellular activity was recorded in vivo using multi-electrode arrays from single units in the LGN in 12 anesthetized rats with a total neuronal population of 150 units. Neural activity was recorded in response to single-pixel, checkerboard and geometrical shapes visual stimulation patterns. Extracted firing rates and the corresponding stimulation patterns were used to train the model. The performance of the model was assessed using different testing data sets and different firing rate windows. An overall mean correlation coefficient between the actual and the predicted firing rates of 0.57 and 0.7 was achieved for the 10 ms and the 50 ms firing rate windows, respectively. Results demonstrate that the model is robust to variability in the spatiotemporal properties of the recorded neurons outperforming other examined models including the state-of-the-art Generalized Linear Model (GLM). The results indicate the potential of deep convolutional neural networks as viable models of LGN firing.


Diagnosis ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert J. Sepanski ◽  
Arno L. Zaritsky ◽  
Sandip A. Godambe

AbstractObjectivesElectronic alert systems to identify potential sepsis in children presenting to the emergency department (ED) often either alert too frequently or fail to detect earlier stages of decompensation where timely treatment might prevent serious outcomes.MethodsWe created a predictive tool that continuously monitors our hospital’s electronic health record during ED visits. The tool incorporates new standards for normal/abnormal vital signs based on data from ∼1.2 million children at 169 hospitals. Eighty-two gold standard (GS) sepsis cases arising within 48 h were identified through retrospective chart review of cases sampled from 35,586 ED visits during 2012 and 2014–2015. An additional 1,027 cases with high severity of illness (SOI) based on 3 M’s All Patient Refined – Diagnosis-Related Groups (APR-DRG) were identified from these and 26,026 additional visits during 2017. An iterative process assigned weights to main factors and interactions significantly associated with GS cases, creating an overall “score” that maximized the sensitivity for GS cases and positive predictive value for high SOI outcomes.ResultsTool implementation began August 2017; subsequent improvements resulted in 77% sensitivity for identifying GS sepsis within 48 h, 22.5% positive predictive value for major/extreme SOI outcomes, and 2% overall firing rate of ED patients. The incidence of high-severity outcomes increased rapidly with tool score. Admitted alert positive patients were hospitalized nearly twice as long as alert negative patients.ConclusionsOur ED-based electronic tool combines high sensitivity in predicting GS sepsis, high predictive value for physiologic decompensation, and a low firing rate. The tool can help optimize critical treatments for these high-risk children.


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