For animals to respond effectively to their environment, their sensory circuits must learn to distinguish between similar patterns of sensory information. A lingering question in neuroscience is how neuronal circuits achieve this performance. In this study, I use the posterior lateral line (pLL) of larval zebrafish to address this question. In the wild, the pLL must differentiate among a variety of hydrodynamic stimuli. However, understanding how fish distinguish between different water-flow stimuli has been challenging due to difficulties in stimulating individual neuromasts. To tackle this, I introduce a novel method in this thesis that combines single-neuromast optogenetics with whole-brain calcium imaging in zebrafish larvae. By optogenetically stimulating individual neuromasts, I observe that second-order circuits in the medial octavolateralis nucleus (MON) exhibit diverse selectivity properties to neuromast input, despite an expected lack of spatiotopy. I further demonstrate that complex combinations of neuromast stimulation are represented by sparse ensembles of neurons within the MON and show that neuromast input integrates in the zebrafish brain through non-linear means. Based on my results, I discuss the implications and limitations of this experimental system, suggest new strategies for enhancement, and detail future directions for using single-neuromast optogenetics to better understand the integrative encoding of directional flow and the developmental capacity of central circuits associated with the pLL. My approach offers an innovative method for spatiotemporally interrogating the zebrafish lateral line system and presents a valuable model for studying whole-brain sensory encoding.
","abstract_html":"<p>For animals to respond effectively to their environment, their sensory circuits must learn to distinguish between similar patterns of sensory information. A lingering question in neuroscience is how neuronal circuits achieve this performance. In this study, I use the posterior lateral line (pLL) of larval zebrafish to address this question. In the wild, the pLL must differentiate among a variety of hydrodynamic stimuli. However, understanding how fish distinguish between different water-flow stimuli has been challenging due to difficulties in stimulating individual neuromasts. To tackle this, I introduce a novel method in this thesis that combines single-neuromast optogenetics with whole-brain calcium imaging in zebrafish larvae. By optogenetically stimulating individual neuromasts, I observe that second-order circuits in the medial octavolateralis nucleus (MON) exhibit diverse selectivity properties to neuromast input, despite an expected lack of spatiotopy. I further demonstrate that complex combinations of neuromast stimulation are represented by sparse ensembles of neurons within the MON and show that neuromast input integrates in the zebrafish brain through non-linear means. Based on my results, I discuss the implications and limitations of this experimental system, suggest new strategies for enhancement, and detail future directions for using single-neuromast optogenetics to better understand the integrative encoding of directional flow and the developmental capacity of central circuits associated with the pLL. My approach offers an innovative method for spatiotemporally interrogating the zebrafish lateral line system and presents a valuable model for studying whole-brain sensory encoding.</p>","abstract_has_math":false,"creators":["Velez-Angel, Nicolas"],"institution":null,"degree_name":"Doctor of Philosophy (PhD)","degree_level":"Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":["A. James Hudspeth"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-01-01T08:00:00Z","date_published":"2025-01-01T08:00:00Z","updated_at":"2026-07-24T04:10:47Z","subjects":["zebrafish","posterior lateral line","neuromast","optogenetics","sensory encoding","calcium imaging","Life Sciences"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://digitalcommons.rockefeller.edu/student_theses_and_dissertations/828","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["A. 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A lingering question in neuroscience is how neuronal circuits achieve this performance. In this study, I use the posterior lateral line (pLL) of larval zebrafish to address this question. In the wild, the pLL must differentiate among a variety of hydrodynamic stimuli. However, understanding how fish distinguish between different water-flow stimuli has been challenging due to difficulties in stimulating individual neuromasts. To tackle this, I introduce a novel method in this thesis that combines single-neuromast optogenetics with whole-brain calcium imaging in zebrafish larvae. By optogenetically stimulating individual neuromasts, I observe that second-order circuits in the medial octavolateralis nucleus (MON) exhibit diverse selectivity properties to neuromast input, despite an expected lack of spatiotopy. I further demonstrate that complex combinations of neuromast stimulation are represented by sparse ensembles of neurons within the MON and show that neuromast input integrates in the zebrafish brain through non-linear means. Based on my results, I discuss the implications and limitations of this experimental system, suggest new strategies for enhancement, and detail future directions for using single-neuromast optogenetics to better understand the integrative encoding of directional flow and the developmental capacity of central circuits associated with the pLL. My approach offers an innovative method for spatiotemporally interrogating the zebrafish lateral line system and presents a valuable model for studying whole-brain sensory encoding.
"]},{"key":"dc:title","label":"Title","values":["Neuromast Optogenetics Reveals Rules of Spatial Encoding in the Zebrafish Lateral Line"]}]}],"canonical_facts":{"dc:contributor":["A. James Hudspeth"],"dc:creator":["Velez-Angel, Nicolas"],"dc:description.abstract":["For animals to respond effectively to their environment, their sensory circuits must learn to distinguish between similar patterns of sensory information. A lingering question in neuroscience is how neuronal circuits achieve this performance. In this study, I use the posterior lateral line (pLL) of larval zebrafish to address this question. In the wild, the pLL must differentiate among a variety of hydrodynamic stimuli. However, understanding how fish distinguish between different water-flow stimuli has been challenging due to difficulties in stimulating individual neuromasts. To tackle this, I introduce a novel method in this thesis that combines single-neuromast optogenetics with whole-brain calcium imaging in zebrafish larvae. By optogenetically stimulating individual neuromasts, I observe that second-order circuits in the medial octavolateralis nucleus (MON) exhibit diverse selectivity properties to neuromast input, despite an expected lack of spatiotopy. I further demonstrate that complex combinations of neuromast stimulation are represented by sparse ensembles of neurons within the MON and show that neuromast input integrates in the zebrafish brain through non-linear means. Based on my results, I discuss the implications and limitations of this experimental system, suggest new strategies for enhancement, and detail future directions for using single-neuromast optogenetics to better understand the integrative encoding of directional flow and the developmental capacity of central circuits associated with the pLL. My approach offers an innovative method for spatiotemporally interrogating the zebrafish lateral line system and presents a valuable model for studying whole-brain sensory encoding.
"],"dc:identifier":["https://digitalcommons.rockefeller.edu/student_theses_and_dissertations/828"],"dc:subject":["zebrafish","posterior lateral line","neuromast","optogenetics","sensory encoding","calcium imaging","Life Sciences"],"dc:title":["Neuromast Optogenetics Reveals Rules of Spatial Encoding in the Zebrafish Lateral Line"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T04:10:47Z"}