Peripheral optogenetic stimulation induces whisker movement and sensory perception in head-fixed mice
| Autor: | Akhil Bandi, David J. Margolis, Christian R. Lee, Sunmee Park |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
animal structures Mouse QH301-705.5 Movement Science Mice Transgenic Stimulation Optogenetics Stimulus (physiology) Somatosensory system General Biochemistry Genetics and Molecular Biology 03 medical and health sciences 0302 clinical medicine Whisker Animals sensorimotor integration Biology (General) channelrhodopsin-2 integumentary system General Immunology and Microbiology active sensation Chemistry General Neuroscience Whisking in animals Electroencephalography tactile learning Somatosensory Cortex General Medicine Anatomy Barrel cortex Tools and Resources Peripheral 030104 developmental biology mystacial vibrissae Vibrissae barrel cortex Medicine Perception Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | eLife, Vol 5 (2016) eLife |
| ISSN: | 2050-084X |
| DOI: | 10.7554/elife.14140 |
| Popis: | We discovered that optical stimulation of the mystacial pad in Emx1-Cre;Ai27D transgenic mice induces whisker movements due to activation of ChR2 expressed in muscles controlling retraction and protraction. Using high-speed videography in anesthetized mice, we characterize the amplitude of whisker protractions evoked by varying the intensity, duration, and frequency of optogenetic stimulation. Recordings from primary somatosensory cortex (S1) in anesthetized mice indicated that optogenetic whisker pad stimulation evokes robust yet longer latency responses than mechanical whisker stimulation. In head-fixed mice trained to report optogenetic whisker pad stimulation, psychometric curves showed similar dependence on stimulus duration as evoked whisker movements and S1 activity. Furthermore, optogenetic stimulation of S1 in expert mice was sufficient to substitute for peripheral stimulation. We conclude that whisker protractions evoked by optogenetic activation of whisker pad muscles results in cortical activity and sensory perception, consistent with the coding of evoked whisker movements by reafferent sensory input. DOI: http://dx.doi.org/10.7554/eLife.14140.001 eLife digest Mice use their whiskers to sense their environment and to detect nearby objects. Rather than simply allowing their whiskers to brush passively against objects, mice move them in rhythmic bursts in a process called whisking. Whisking enables neuroscientists to study how the brain gathers and processes actively acquired sensory information. However, controlling active whisker movements in the laboratory has proven challenging. Park et al. now offer a solution based on a technique called optogenetics. The new procedure involves introducing the gene for a light-sensitive ion channel into the facial muscles of the mouse. Shining blue light onto the area of skin where the whiskers grow – the whisker pad – activates these ion channels. Park et al. were able to use this technique to trigger the contraction of the facial muscles and the movement of the whiskers. Furthermore, stimulating different muscles in different areas of the whisker pad produced either forward or backward whisker movements. The strength of the whisker movements varied with the intensity of the light, and with how often and for how long light was applied. Recordings of neural activity showed that sensory signals from light-induced whisker movements reach the same region of the brain as signals from natural whisker movements. Behavioral experiments showed that mice could perceive these whisker movements, despite the fact that they did not generate them. By establishing a method for triggering whisker movements on demand, Park et al. have provided a convenient way of investigating active sensory processing. In addition, this method opens up new possibilities for using optogenetics after injury or degeneration of the nerves that control movement. Ultimately, by using light to trigger muscle contraction directly, it may be possible to restore movement in individuals who have sustained nerve damage through injury or disease. DOI: http://dx.doi.org/10.7554/eLife.14140.002 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|