Search results for "Optogenetics"
showing 10 items of 34 documents
Proceedings of the Eighth Annual Deep Brain Stimulation Think Tank: Advances in Optogenetics, Ethical Issues Affecting DBS Research, Neuromodulatory …
2021
We estimate that 208,000 deep brain stimulation (DBS) devices have been implanted to address neurological and neuropsychiatric disorders worldwide. DBS Think Tank presenters pooled data and determined that DBS expanded in its scope and has been applied to multiple brain disorders in an effort to modulate neural circuitry. The DBS Think Tank was founded in 2012 providing a space where clinicians, engineers, researchers from industry and academia discuss current and emerging DBS technologies and logistical and ethical issues facing the field. The emphasis is on cutting edge research and collaboration aimed to advance the DBS field. The Eighth Annual DBS Think Tank was held virtually on Septem…
In vivo Imaging of Fully Active Brain Tissue in Awake Zebrafish Larvae and Juveniles by Skull and Skin Removal.
2021
Understanding the ephemeral changes that occur during brain development and maturation requires detailed high-resolution imaging in space and time at cellular and subcellular resolution. Advances in molecular and imaging technologies have allowed us to gain numerous detailed insights into cellular and molecular mechanisms of brain development in the transparent zebrafish embryo. Recently, processes of refinement of neuronal connectivity that occur at later larval stages several weeks after fertilization, which are for example control of social behavior, decision making or motivation-driven behavior, have moved into focus of research. At these stages, pigmentation of the zebrafish skin inter…
Optogenetics in Stem Cell Research: Focus on the Central Nervous System
2017
Stem cell-based therapies of CNS disorders represent a promising approach in translational and regenerative medicine. Stem cell-based tissue replacement and regeneration would, for the first time, offer a causal treatment strategy which is most likely not bound to a specific time window. Therapeutic strategies relying on this paradigm would require administration of exogenous stem cells to the CNS and/or the augmentation of endogenous stem cell capabilities. However, it remains unclear whether tissue replacement or bystander effects are required to induce such effects. Conventional experimental techniques will not be able to causally reveal such information, due to the complexity and coinci…
Making Waves: Initiation and Propagation of Corticothalamic Ca2+ Waves In Vivo
2013
Corticothalamic slow oscillations of neuronal activity determine internal brain states. At least in the cortex, the electrical activity is associated with large neuronal Ca(2+) transients. Here we implemented an optogenetic approach to explore causal features of the generation of slow oscillation-associated Ca(2+) waves in the in vivo mouse brain. We demonstrate that brief optogenetic stimulation (3-20 ms) of a local group of layer 5 cortical neurons is sufficient for the induction of global brain Ca(2+) waves. These Ca(2+) waves are evoked in an all-or-none manner, exhibit refractoriness during repetitive stimulation, and propagate over long distances. By local optogenetic stimulation, we …
Food Sensation Modulates Locomotion by Dopamine and Neuropeptide Signaling in a Distributed Neuronal Network
2018
Finding food and remaining at a food source are crucial survival strategies. We show how neural circuits and signaling molecules regulate these food-related behaviors in Caenorhabditis elegans. In the absence of food, AVK interneurons release FLP-1 neuropeptides that inhibit motorneurons to regulate body posture and velocity, thereby promoting dispersal. Conversely, AVK photoinhibition promoted dwelling behavior. We identified FLP-1 receptors required for these effects in distinct motoneurons. The DVA interneuron antagonizes signaling from AVK by releasing cholecystokinin-like neuropeptides that potentiate cholinergic neurons, in response to dopaminergic neurons that sense food. Dopamine al…
Convergence of Cortical and Sensory Driver Inputs on Single Thalamocortical Cells
2013
Ascending and descending information is relayed through the thalamus via strong, "driver" pathways. According to our current knowledge, different driver pathways are organized in parallel streams and do not interact at the thalamic level. Using an electron microscopic approach combined with optogenetics and in vivo physiology, we examined whether driver inputs arising from different sources can interact at single thalamocortical cells in the rodent somatosensory thalamus (nucleus posterior, POm). Both the anatomical and the physiological data demonstrated that ascending driver inputs from the brainstem and descending driver inputs from cortical layer 5 pyramidal neurons converge and interac…
Mechanisms Underlying Memory Consolidation by Adult-Born Neurons During Sleep
2020
The mammalian hippocampus generates new neurons that incorporate into existing neuronal networks throughout the lifespan, which bestows a unique form of cellular plasticity to the memory system. Recently, we found that hippocampal adult-born neurons (ABNs) that were active during learning reactivate during subsequent rapid eye movement (REM) sleep and provided causal evidence that ABN activity during REM sleep is necessary for memory consolidation. Here, we describe the potential underlying mechanisms by highlighting distinct characteristics of ABNs including decoupled firing from local oscillations and ability to undergo profound synaptic remodeling in response to experience. We further di…
Navigating the translational roadblock: Towards highly specific and effective all-optical interrogations of neural circuits
2020
AbstractTwo-photon (2-P) all-optical approaches combine in vivo 2-P calcium imaging and 2-P optogenetic modulations and have the potential to build a framework for network-based therapies, e.g. for rebalancing maladaptive activity patterns in preclinical models of neurological disorders. Here, our goal was to tailor these approaches for this purpose: Firstly, we combined in vivo juxtacellular recordings and GCaMP6f-based 2-P calcium imaging in layer II/III of mouse visual cortex to tune our detection algorithm towards a 100 % specific identification of AP-related calcium transients. False-positive-free detection was achieved at a sensitivity of approximately 73 %. To further increase specif…
Kinetics of proton release and uptake by channelrhodopsin-2
2012
Electrophysiological experiments showed that the light-activated cation channel channelrhodopsin-2 (ChR2) pumps protons in the absence of a membrane potential. We determined here the kinetics of transient pH change using a water-soluble pH-indicator. It is shown that ChR2 released protons prior to uptake with a stoichiometry of 0.3 protons per ChR2. Comparison to the photocycle kinetics revealed that proton release and uptake match rise and decay of the View the MathML sourceP3520 intermediate. As the View the MathML sourceP3520 state also represents the conductive state of cation channeling, the concurrence of proton pumping and channel gating implies an intimate mechanistic link of the tw…
Red Light Optogenetics in Neuroscience
2022
Optogenetics, a field concentrating on controlling cellular functions by means of light-activated proteins, has shown tremendous potential in neuroscience. It possesses superior spatiotemporal resolution compared to the surgical, electrical, and pharmacological methods traditionally used in studying brain function. A multitude of optogenetic tools for neuroscience have been created that, for example, enable the control of action potential generation via light-activated ion channels. Other optogenetic proteins have been used in the brain, for example, to control long-term potentiation or to ablate specific subtypes of neurons. In in vivo applications, however, the majority of optogenetic too…