Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers
Tonic inhibition was imaged in cerebellar granule cells of transgenic mice expressing the optogenetic chloride indicator, Clomeleon. Blockade of GABAA receptors substantially reduced chloride concentration in granule cells due to block of tonic inhibition. This indicates that tonic inhibition is a s...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2016
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| Online Access: | https://hdl.handle.net/10356/81981 http://hdl.handle.net/10220/41039 |
| _version_ | 1811680429595426816 |
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| author | Berglund, Ken Wen, Lei Dunbar, Robert L. Feng, Guoping Augustine, George James |
| author2 | Lee Kong Chian School of Medicine (LKCMedicine) |
| author_facet | Lee Kong Chian School of Medicine (LKCMedicine) Berglund, Ken Wen, Lei Dunbar, Robert L. Feng, Guoping Augustine, George James |
| author_sort | Berglund, Ken |
| collection | NTU |
| description | Tonic inhibition was imaged in cerebellar granule cells of transgenic mice expressing the optogenetic chloride indicator, Clomeleon. Blockade of GABAA receptors substantially reduced chloride concentration in granule cells due to block of tonic inhibition. This indicates that tonic inhibition is a significant contributor to the resting chloride concentration of these cells. Tonic inhibition was observed not only in granule cell bodies, but also in their axons, the parallel fibers (PFs). This presynaptic tonic inhibition could be observed in slices both at room and physiological temperatures, as well as in vivo, and has many of the same properties as tonic inhibition measured in granule cell bodies. GABA application revealed that PFs possess at least two types of GABAA receptor: one high-affinity receptor that is activated by ambient GABA and causes a chloride influx that mediates tonic inhibition, and a second with a low affinity for GABA that causes a chloride efflux that excites PFs. Presynaptic tonic inhibition regulates glutamate release from PFs because GABAA receptor blockade enhanced both the frequency of spontaneous EPSCs and the amplitude of evoked EPSCs at the PF-Purkinje cell synapse. We conclude that tonic inhibition of PFs could play an important role in regulating information flow though cerebellar synaptic circuits. Such cross talk between phasic and tonic signaling could be a general mechanism for fine tuning of synaptic circuits. |
| first_indexed | 2024-10-01T03:24:55Z |
| format | Journal Article |
| id | ntu-10356/81981 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T03:24:55Z |
| publishDate | 2016 |
| record_format | dspace |
| spelling | ntu-10356/819812022-02-16T16:27:08Z Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers Berglund, Ken Wen, Lei Dunbar, Robert L. Feng, Guoping Augustine, George James Lee Kong Chian School of Medicine (LKCMedicine) Tonic inhibition Parallel fibers Tonic inhibition was imaged in cerebellar granule cells of transgenic mice expressing the optogenetic chloride indicator, Clomeleon. Blockade of GABAA receptors substantially reduced chloride concentration in granule cells due to block of tonic inhibition. This indicates that tonic inhibition is a significant contributor to the resting chloride concentration of these cells. Tonic inhibition was observed not only in granule cell bodies, but also in their axons, the parallel fibers (PFs). This presynaptic tonic inhibition could be observed in slices both at room and physiological temperatures, as well as in vivo, and has many of the same properties as tonic inhibition measured in granule cell bodies. GABA application revealed that PFs possess at least two types of GABAA receptor: one high-affinity receptor that is activated by ambient GABA and causes a chloride influx that mediates tonic inhibition, and a second with a low affinity for GABA that causes a chloride efflux that excites PFs. Presynaptic tonic inhibition regulates glutamate release from PFs because GABAA receptor blockade enhanced both the frequency of spontaneous EPSCs and the amplitude of evoked EPSCs at the PF-Purkinje cell synapse. We conclude that tonic inhibition of PFs could play an important role in regulating information flow though cerebellar synaptic circuits. Such cross talk between phasic and tonic signaling could be a general mechanism for fine tuning of synaptic circuits. NRF (Natl Research Foundation, S’pore) Published version 2016-08-02T05:44:45Z 2019-12-06T14:44:11Z 2016-08-02T05:44:45Z 2019-12-06T14:44:11Z 2016 Journal Article Berglund, K., Wen, L., Dunbar, R. L., Feng, G., & Augustine, G. J. (2016). Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers. Journal of Neuroscience, 36(21), 5709-5723. 0270-6474 https://hdl.handle.net/10356/81981 http://hdl.handle.net/10220/41039 10.1523/JNEUROSCI.4366-15.2016 27225762 en Journal of Neuroscience © 2016 The Authors. This paper was published in Journal of Neuroscience and is made available as an electronic reprint (preprint) with permission of Society for Neuroscience. The published version is available at: [http://dx.doi.org/10.1523/JNEUROSCI.4366-15.2016]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law. 15 p. application/pdf |
| spellingShingle | Tonic inhibition Parallel fibers Berglund, Ken Wen, Lei Dunbar, Robert L. Feng, Guoping Augustine, George James Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers |
| title | Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers |
| title_full | Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers |
| title_fullStr | Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers |
| title_full_unstemmed | Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers |
| title_short | Optogenetic Visualization of Presynaptic Tonic Inhibition of Cerebellar Parallel Fibers |
| title_sort | optogenetic visualization of presynaptic tonic inhibition of cerebellar parallel fibers |
| topic | Tonic inhibition Parallel fibers |
| url | https://hdl.handle.net/10356/81981 http://hdl.handle.net/10220/41039 |
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