Over the past few decades, much progress has been made in the clinical use of electrical stimulation of the central nervous system (CNS) to treat an ever-growing number of conditions from Parkinson’s disease (PD) to epilepsy as well as for sensory restoration and many other applications. However, little is known about the effects of microstimulation at the cellular level. Most of the existing research focuses on the effects of electrical stimulation on neurons. Other cells of the CNS such as microglia, astrocytes, oligodendrocytes, and vascular endothelial cells have been understudied in terms of their response to stimulation. The varied and critical functions of these cell types are now beginning to be better understood, and their vital roles in brain function in both health and disease are becoming better appreciated. To shed light on the importance of the way electrical stimulation as distinct from device implantation impacts non-neuronal cell types, this review will first summarize common stimulation modalities from the perspective of device design and stimulation parameters and how these different parameters have an impact on the physiological response. Following this, what is known about the responses of different cell types to different stimulation modalities will be summarized, drawing on findings from both clinical studies as well as clinically relevant animal models and in vitro systems.
Nurse-led triage, using the South African Triage Scale, was introduced to the emergency centre of the tertiary referral hospital in Freetown, Sierra Leone in early 2014 prior to the Ebola epidemic. The aim of this study was to measure the effectiveness of the process now that the country has been declared free of Ebola.The study was conducted over a five-day consecutive period in the adult emergency centre of the main government teaching hospital in December 2015. The times from arrival to triage and medical assessment were recorded and compared for each triage category. We also assessed the inter-rater reliability of the process.111 patients were included during the study period. In terms of acuity, 6% were categorised as red, 27% were orange, 20% yellow and 47% green. Triage Early Warning Score was correctly calculated in 90% of cases and there was inter-rater agreement of colour code and triage category on 92% of occasions (k = 0.877, p < 0.001). Median time from triage to assessment was 15 min for red patients, 20 min for orange, 40 min for yellow and 72 min for green.The triage process is functioning effectively in the emergency centre after the Ebola epidemic and provides a reliable assessment of undifferentiated patients presenting to the hospital to ensure that they are seen in a timely manner based on acuity.Le triage réalisé par les infirmières, qui se base sur l’Echelle de triage sud-africaine (SATS, South African Triage Scale), a été introduit au service des urgences de l’hôpital tertiaire de référence de Freetown, en Sierra Leone, au début d’année 2014, avant l’épidémie d’Ebola. L’objectif était d’évaluer l’efficacité du processus maintenant que le risque pour le pays a été déclaré inexistant.Méthodes : L’étude a été menée sur une période consécutive de cinq jours au service des urgences du principal hôpital universitaire public en décembre 2015. Le temps écoulé entre l’arrivée et le triage et l’examen médical a été consigné et comparé pour chaque catégorie de triage. Nous avons également évalué le coefficient d’objectivité du processus.111 patients ont été inclus sur la période de l’étude. En termes de gravité, 6 % étaient classés en rouge, 27 % en orange, 20 % en jaune et 47 % en vert. La note accordée aux alertes rapides découlant du triage (TEWS, Triage Early Warning Score) a été correctement calculée dans 90 % des cas et la concordance inter-évaluateurs sur les codes couleurs et les catégories de triage a été observée dans 92 % des cas (k = 0,877, p < 0,001). Le temps moyen du triage à l’examen était de 15 minute pour les patients en catégorie rouge, de 20 minute en catégorie orange, 40 minute en catégorie jaune et 72 minute en catégorie verte.Le processus de triage fonctionne efficacement au service des urgences après l’épidémie d’Ebola et fournit une évaluation fiable des patients non différentiés se présentant à l’hôpital, afin de s’assurer qu’ils voient un médecin en temps opportun en fonction de la gravité de leur état.
A series of tricyanovinyl (TCV)-substituted oligothiophenes was synthesized and investigated with a number of physical methods including UV/Vis, IR, and Raman spectroscopy, nonlinear optical (NLO) measurements, X-ray diffraction, and cyclic voltammetry. Mono- or disubstituted oligomers were prepared by the reaction of tetracyanoethylene with mono- or dilithiated oligomers. The comparative effects of the symmetric and asymmetric substitutions in the electronic and molecular properties have been addressed. These oligomers display dramatic reductions in both their optical and electrochemical band gaps in comparison with unsubstituted molecules. The analysis of the electronic properties of the molecules was assisted by density functional theory calculations, which are in excellent agreement with the experimental data. TCV substitution influences the energies of the frontier orbitals, especially with respect to the stabilization of LUMO orbitals. X-ray structural characterization of a monosubstituted oligomer exhibits pi-stacking with favorable intermolecular interactions. NLO results agree with the role of the intramolecular charge-transfer feature in the asymmetric samples. These results furthermore exalt the role of conformational flexibility in the disubstituted compounds and reveal an unexpected nonlinear optical activity for symmetric molecules. Regarding the electronic structure, the interpretation of the vibrational data reflects the balanced interplay between aromatic and quinoid forms, finely tuned by the chain length and substitution pattern. The electronic and structural properties are consistent with the semiconducting properties exhibited by these materials in thin film transistors (TFTs).
Cerebral neural electronics play a crucial role in neuroscience research with increasing translational applications such as brain-computer interfaces for sensory input and motor output restoration. While widely utilized for decades, the understanding of the cellular mechanisms underlying this technology remains limited. Although two-photon microscopy (TPM) has shown great promise in imaging superficial neural electrodes, its application to deep-penetrating electrodes is technically difficult. Here, a novel device integrating transparent microelectrode arrays with glass microprisms, enabling electrophysiology recording and stimulation alongside TPM imaging across all cortical layers in a vertical plane, is introduced. Tested in Thy1-GCaMP6 mice for over 4 months, the integrated device demonstrates the capability for multisite electrophysiological recording/stimulation and simultaneous TPM calcium imaging. As a proof of concept, the impact of microstimulation amplitude, frequency, and depth on neural activation patterns is investigated using the setup. With future improvements in material stability and single unit yield, this multimodal tool greatly expands integrated electrophysiology and optical imaging from the superficial brain to the entire cortical column, opening new avenues for neuroscience research and neurotechnology development.
An .xlsx formatted table of summary data for all neurons analyzed. Data is the average firing rate 75 to 375 ms post image onset. Each cell is the average of 4 trials for the given condition, presented in pseudorandom order during a recording session. Rows are neurons, columns are conditions. Data Organization: Row: rows 1-32 are monkey1, neurons 1-32, tetrad1 rows 33-111 are monkey2, neurons 1-79, tetrad1 rows 112-143 are monkey1, neurons 1-32, tetrad2 rows 144-222 are monkey2, neurons 1-79, tetrad2 Column: 1: prime response, neither match condition, shape1 color1 2: prime response, neither match condition, shape1 color2 3: prime response, neither match condition, shape2 color1 4: prime response, neither match condition, shape2 color2 5: prime response, shape match condition, shape1 color1 6: prime response, shape match condition, shape1 color2 7: prime response, shape match condition, shape2 color1 8: prime response, shape match condition, shape2 color2 9: prime response, color match condition, shape1 color1 10: prime response, color match condition, shape1 color2 11: prime response, color match condition, shape2 color1 12: prime response, color match condition, shape2 color2 13: prime response, both match condition, shape1 color1 14: prime response, both match condition, shape1 color2 15: prime response, both match condition, shape2 color1 16: prime response, both match condition, shape2 color2 17: probe response, neither match condition, shape1 color1 18: probe response, neither match condition, shape1 color2 19: probe response, neither match condition, shape2 color1 20: probe response, neither match condition, shape2 color2 21: probe response, shape match condition, shape1 color1 22: probe response, shape match condition, shape1 color2 23: probe response, shape match condition, shape2 color1 24: probe response, shape match condition, shape2 color2 25: probe response, color match condition, shape1 color1 26: probe response, color match condition, shape1 color2 27: probe response, color match condition, shape2 color1 28: probe response, color match condition, shape2 color2 29: probe response, both match condition, shape1 color1 30: probe response, both match condition, shape1 color2 31: probe response, both match condition, shape2 color1 32: probe response, both match condition, shape2 color2
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