Functional changes in connectivity induced by differential manipulations of activity in Drosophila tonic versus phasic motoneurons
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biology, May, 2020
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2021
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| Online Access: | https://hdl.handle.net/1721.1/130188 |
| _version_ | 1826193061934268416 |
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| author | Aponte Santiago, Nicole Ann. |
| author2 | J. Troy Littleton. |
| author_facet | J. Troy Littleton. Aponte Santiago, Nicole Ann. |
| author_sort | Aponte Santiago, Nicole Ann. |
| collection | MIT |
| description | Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biology, May, 2020 |
| first_indexed | 2024-09-23T09:33:10Z |
| format | Thesis |
| id | mit-1721.1/130188 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T09:33:10Z |
| publishDate | 2021 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/1301882021-03-23T03:32:43Z Functional changes in connectivity induced by differential manipulations of activity in Drosophila tonic versus phasic motoneurons Aponte Santiago, Nicole Ann. J. Troy Littleton. Massachusetts Institute of Technology. Department of Biology. Massachusetts Institute of Technology. Department of Biology Biology. Thesis: Ph. D., Massachusetts Institute of Technology, Department of Biology, May, 2020 Cataloged from student-submitted PDF of thesis. Includes bibliographical references. Structural and functional plasticity induced by neuronal competition is a common feature of developing nervous systems. However, the rules governing how postsynaptic cells differentiate between presynaptic inputs are unclear. In this thesis, I characterized synaptic interactions following manipulations of Ib tonic or Is phasic glutamatergic motoneurons that co-innervate postsynaptic muscles at Drosophila neuromuscular junctions (NMJs). After identifying drivers for each neuronal subtype, I performed ablation or genetic manipulations to alter neuronal activity and examined the effects on synaptic innervation and function. Ablation of either Ib or Is resulted in decreased muscle response, with some functional compensation occurring in the tonic Ib input when Is was missing. In contrast, the phasic Is terminal failed to show functional or structural changes following loss of the co-innervating Ib input. Decreasing the activity of the Ib or Is neuron with tetanus toxin light chain resulted in structural changes in muscle innervation. Decreased Ib activity resulted in reduced active zone (AZ) number and decreased postsynaptic subsynaptic reticulum (SSR) volume, with the emergence of filopodial-like protrusions from synaptic boutons of the Ib input. Decreased Is activity did not induce structural changes at its own synapses, but the co-innervating Ib motoneuron increased the number of synaptic boutons and AZs it formed. These findings indicate tonic and phasic neurons respond independently to changes in activity, with either functional or structural alterations in the tonic motoneuron occurring following loss or reduced activity of the co-innervating phasic input, respectively. This thesis work contributes to the understanding of how multiple neuronal inputs innervating one postsynaptic muscle interact. by Nicole Ann Aponte Santiago. Ph. D. Ph.D. Massachusetts Institute of Technology, Department of Biology 2021-03-22T17:09:08Z 2021-03-22T17:09:08Z 2020 2020 Thesis https://hdl.handle.net/1721.1/130188 1241091825 eng MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided. http://dspace.mit.edu/handle/1721.1/7582 156 pages application/pdf Massachusetts Institute of Technology |
| spellingShingle | Biology. Aponte Santiago, Nicole Ann. Functional changes in connectivity induced by differential manipulations of activity in Drosophila tonic versus phasic motoneurons |
| title | Functional changes in connectivity induced by differential manipulations of activity in Drosophila tonic versus phasic motoneurons |
| title_full | Functional changes in connectivity induced by differential manipulations of activity in Drosophila tonic versus phasic motoneurons |
| title_fullStr | Functional changes in connectivity induced by differential manipulations of activity in Drosophila tonic versus phasic motoneurons |
| title_full_unstemmed | Functional changes in connectivity induced by differential manipulations of activity in Drosophila tonic versus phasic motoneurons |
| title_short | Functional changes in connectivity induced by differential manipulations of activity in Drosophila tonic versus phasic motoneurons |
| title_sort | functional changes in connectivity induced by differential manipulations of activity in drosophila tonic versus phasic motoneurons |
| topic | Biology. |
| url | https://hdl.handle.net/1721.1/130188 |
| work_keys_str_mv | AT apontesantiagonicoleann functionalchangesinconnectivityinducedbydifferentialmanipulationsofactivityindrosophilatonicversusphasicmotoneurons |