Université de Sherbrooke

About: Université de Sherbrooke is a education organization based out in Sherbrooke, Quebec, Canada. It is known for research contribution in the topics: Population & Receptor. The organization has 14922 authors who have published 28783 publications receiving 792511 citations. The organization is also known as: Universite de Sherbrooke & Sherbrooke University.

Spinal CCL2 pronociceptive action is no longer effective in CCR2 receptor antagonist-treated rats

Abstract: A better understanding of the mechanisms linked to chemokine pronociceptive effects is essential for the development of new strategies to better prevent and treat chronic pain Among chemokines, MCP-1/CCL2 involvement in neuropathic pain processing is now established However, the mechanisms by which MCP-1/CCL2 exerts its pronociceptive effects are still poorly understood In the present study, we demonstrate that MCP-1/CCL2 can alter pain neurotransmission in healthy rats Using immunohistochemical studies, we first show that CCL2 is constitutively expressed by primary afferent neurons and their processes in the dorsal horn of the spinal cord We also observe that CCL2 is co-localized with pain-related peptides (SP and CGRP) and capsaicin receptor (VR1) Accordingly, using in vitro superfusion system of lumbar dorsal root ganglion and spinal cord explants of healthy rats, we show that potassium or capsaicin evoke calcium-dependent release of CCL2 In vivo, we demonstrate that intrathecal administration of CCL2 to healthy rats produces both thermal hyperalgesia and sustained mechanical allodynia (up to four consecutive days) These pronociceptive effects of CCL2 are completely prevented by the selective CCR2 antagonist (INCB3344), indicating that CCL2-induced pain facilitation is elicited via direct spinal activation of CCR2 receptor Therefore, preventing the activation of CCR2 might provide a fruitful strategy for treating pain

Fast and Unconditional All-Microwave Reset of a Superconducting Qubit.

Abstract: Active qubit reset is a key operation in many quantum algorithms, and particularly in quantum error correction. Here, we experimentally demonstrate a reset scheme for a three-level transmon artificial atom coupled to a large bandwidth resonator. The reset protocol uses a microwave-induced interaction between the $|f,0⟩$ and $|g,1⟩$ states of the coupled transmon-resonator system, with $|g⟩$ and $|f⟩$ denoting the ground and second excited states of the transmon, and $|0⟩$ and $|1⟩$ the photon Fock states of the resonator. We characterize the reset process and demonstrate reinitialization of the transmon-resonator system to its ground state in less than 500 ns and with 0.2% residual excitation. Our protocol is of practical interest as it has no additional architectural requirements beyond those needed for fast and efficient single-shot readout of transmons, and does not require feedback.

Interacting two-level defects as sources of fluctuating high-frequency noise in superconducting circuits

Abstract: Since the very first experiments, superconducting circuits have suffered from strong coupling to environmental noise, destroying quantum coherence and degrading performance. In state-of-the-art experiments, it is found that the relaxation time of superconducting qubits fluctuates as a function of time. We present measurements of such fluctuations in a 3D-transmon circuit and develop a qualitative model based on interactions within a bath of background two-level systems (TLS) which emerge from defects in the device material. In our model, the time-dependent noise density acting on the qubit emerges from its near-resonant coupling to high-frequency TLS which experience energy fluctuations due to their interaction with thermally fluctuating TLS at low frequencies. We support the model by providing experimental evidence of such energy fluctuations observed in a single TLS in a phase qubit circuit.

The Physiology of Pain Mechanisms: From the Periphery to the Brain

Abstract: This article introduces the scientific basis for the understanding of pain mechanisms and highlights the importance of endogenous excitatory and inhibitory controls in the central nervous system. These innate control systems have an impact on the evolution of chronic pain and may be manipulated to alter the pain process, and therefore have implications regarding treatment. Understanding neurophysiologic mechanisms involved in the development and maintenance of pain can help the clinician to devise a more effective treatment plan guided by pathophysiologic dysfunction. Keeping in mind the heterogeneity of the pain response and the unique characteristics of an individual patient will lead to better patient care.