Search results for "Stimulation"
showing 10 items of 2192 documents
Power-effective scanning with AODs for 3D optogenic applications
2022
Two-photon (2P) excitation is a cornerstone approach widely employed in neuroscience microscopy for deep optical access and sub-micrometric-resolution light targeting into the brain. However, besides structural and functional imaging, 2P optogenetic stimulations are less routinary, especially in 3D. This is because of the adopted scanning systems, often feebly effective, slow and mechanically constricted. Faster illumination can be achieved through acousto-optic deflectors (AODs) although their applicability to large volumes excitation has been limited by large efficiency drop along the optical axis. Here, we present a new AOD-based scheme for 2P 3D scanning that improves the power delivery…
A method for rapid implantation of multielectrode systems.
1991
The implantation of several chronic electrodes at the same time was needed for the studies in which both evoked slow potential and multiple unit neural activity of different brain sites were recorded during classical conditioning in freely moving cats. The recording electrodes were made of 25-75 microns insulated stainless steel or nichrome wires which were inserted into a thin hypodermic needle of a fixed, calibrated length. The fast implantation system described here is based on the use of a stereotaxic frame as a stand for a drill and as a support for an electrode holder with which the electrodes were implanted through precision holes drilled directly according to the coordinates of the …
On the current neuroenhancement use of transcranial direct current stimulation by healthy individuals—A non-fictional snap-shot: Commentary on Lapent…
2014
This commentary examines the pros and cons of the fictitious enhancement scenarios used in Lapenta et al. 2014. Then it gives a non-fictional impression of the current self-enhancement use of transcranial direct current stimulation (tDCS) by healthy individuals and discusses the ethical issues involved.
A transcranial magnetic stimulation study evaluating methylprednisolone treatment in multiple sclerosis
2002
Objective - To investigate the efficacy of two different high doses of intravenous methylprednisolone (IVMP) during Multiple Sclerosis (MS) relapses. Background - Transcranial Magnetic Stimulation (TMS) is the most sensitive neurophysiological ascertainment to quantify motor disability, to follow the recovery from an MS relapse, and to detect the response to treatment. Design and method - Twenty-four clinically definite relapsing - remitting MS patients presenting a relapse were randomly assigned to a treatment for 5 days with IVMP 1 or 2 g/day. The response to treatment of each patient was evaluated through Expanded Disability Status Scale (EDSS), Medical Research Council (MRC) score, and …
NANC inhibitory neurotransmission in mouse isolated stomach: Involvement of nitric oxide, ATP and vasoactive intestinal polypeptide
2003
1. The neurotransmitters involved in NANC relaxation and their possible interactions were investigated in mouse isolated stomach, recording the motor responses as changes of endoluminal pressure from whole organ. 2. Field stimulation produced tetrodotoxin-sensitive, frequency-dependent, biphasic responses: rapid transient relaxation followed by a delayed inhibitory component. 3. The inhibitor of the synthesis of nitric oxide (NO), L-NAME, abolished the rapid relaxation and significantly reduced the slow relaxation. Apamin, blocker of Ca 2+-dependent K + channels, or ADPβS, which desensitises P 2y purinoceptors, reduced the slow relaxation to 2-8 Hz, without affecting that to 16-32 Hz or the…
Modulating fluency with Transcranial Magnetic Stimulation over right or left inferior frontal gyrus
2017
Objective In these last years, a growing body of evidence has already indicated that non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), can modulate the language system in aphasic populations. The aim of this presentation is to investigate for the first time the effects of inhibitory rTMS over the left and right inferior frontal gyrus (IFG) on phonemic fluency tasks. Participants Sixty-six right-handed healthy participants participated in the study. Forty-four had administered offline low-frequency (1 Hz) rTMS for 10 minutes and verbal fluency outcome measures were recorded. Twenty-two participants w…
Activity mappings in olfactory bulb of newborn rabbits elicited by odor stimulation using quantitative manganese enhanced MRI
2007
International audience
Efficacy of obidoxime in human organophosphorus poisoning: determination by neuromuscular transmission studies.
1995
Six patients with organophosphorus compound intoxications developed an intermediate syndrome (weakness and fasciculations) and obidoxime was given on eight occasions. The efficacy of the acetylcholinesterase (AChE) reactivator was monitored electrophysiologically by neuromuscular transmission studies using single and repetitive nerve stimulation (20 and 50 Hz) and the activity of the serum (butyryl) cholinesterase (ChE). Dramatic electrophysiologic improvement was seen when obidoxime was given early within 12 h in 3 patients, although evidence of AChE inhibition did not subside completely. When administration of obidoxime was delayed 26 h or more after intoxication on five occasions, electr…
Interactions of odorants with olfactory receptors and receptor neurons match the perceptual dynamics observed for woody and fruity odorant mixtures
2012
The present study aimed to create a direct bridge between observations on peripheral and central responses to odorant mixtures and their components. Three experiments were performed using mixtures of fruity (isoamyl acetate; ISO) and woody (whiskey lactone; WL) odorants known to contribute to some of the major notes in Burgundy red wine. These experiments consisted of (i) calcium imaging of human embryonic kidney cells (HEK293T) transfected with olfactory receptors (ORs); (ii) single-unit electrophysiological recordings from olfactory receptor neurons (ORNs) and analyses of electro-olfactogram (EOG) responses in the rat nose in vivo; and (iii) psychophysical measurements of the perceived in…
Modifications de l’olfaction au cours du vieillissement et de certaines pathologies neurodégénératives : mise au point
2015
Olfaction is a complex sensory system, and increasing interest is being shown in the link between olfaction and cognition, notably in the elderly. In this literature review, we revisit the specific neurophysiological features of the olfactory system and odorants that lead to a durable olfactory memory and an emotional memory, for which the implicit component produces subconscious olfactory conditioning. Olfaction is known to affect cognitive abilities and mood. We also consider the impairment of olfactory function due to ageing and to neurodegenerative diseases, in particular Alzheimer's disease and Parkinson's disease, through anatomopathological changes in the peripheral and central olfac…