Architecture of Vagal Interoception in the Zebrafish

Authors:

Zoe Schurman, Kristian Herrera, Mariela Petkova, Florian Engert

Date Created:

2025-01-01

Course Title:

Professor:

Not specified

About Paper:

The neural circuitry of interoception, or the sensing and regulation neurotransmitter profile, emerged. One subtype is excitatory, with of internal bodily states, remains poorly understood. To address somas originating in the nucleus of the solitary tract (NTS) and thisgap, weareusingconnectomicanalysisofelectronmicroscopy exclusively ipsilaterally projecting axons. The second subtype, images from a 7-day-old larval zebrafish, aiming to identify neural with somas located more broadly through the hindbrain, has patterns of connectivity between the sensory and motor elements axons which extend both ipsi- and contralaterally. Its anatomical of the vagus nerve. This nerve carries information bidirectionally features and absence of GABAergic or glutamatergic markers between the brain and various organs, including the heart, the point to this subtype releasing glycine, a dominantly inhibitory digestive system, and the pharynx, implying that the vagus nerve neurotransmitter. We hypothesize that these subtypes represent a is a primary mediator of interoception for these systems. Our system of large-scale inhibition paired with localized excitation. project focuses on the pharynx, an organ that contains a diverse This is a common motif in sensory systems (e.g. vision or array of structures in zebrafish, from gills and muscle cells to tastelfaction), increasing contrast between sensory inputs and refining buds. We traced all pharyngeal-projecting vagal motor neurons motor output. It can also help control background noise, which is back to their somata in the hindbrain, along with every presynaptic especially important in the context of a developing animal. Further interneurontothesemotorcells. Weplantofollowthisbymapping research is needed to determine whether this or another circuit the broader network of upstream and downstream connections. architecture regulate pharyngeal interoception in the vagus nerve. Two distinct classes of interneurons, differing in anatomy and Steeringthe Zebrafish: ElucidatingthePresynapticConnectionsofthenMLF Benjamin Selip, Yasuko Isoe, Mariela Petkova Brandeis University | Neuroscience | 2028 Motor control is essential for animals to govern their movements somatic, andaxoniclocationsandsynapticconnections. Currently, and is categorized into rough and fine motor control. Fine motor we focused on four lateral MeS (MeSL1-4) and identified 48 PSNs control is critical for more accurate movements, such as target- for MeSL1, 37 PSNs for MeSL2, 20 PSNs for MeSL3, and 13 gazing eye movements or calligraphy. The circuitry behind fine PSNs for MeSL4. Most PSNs were located in the ipsi- or contra- motor control remains unknown. Previous studies found that a lateral nMLF region with dendrites in the respective intermediate region of the midbrain called the nucleus of Medial Longitudinal hypothalamus and axons extending bilaterally. Spinal neurons Fasciculus (nMLF) is associated with this fine motor movement. were also found, extending axons up into the midbrain. Neurons Zebrafish studies found that a subpopulation within the nMLF, found within the cerebellum and optic areas formed synapses with mesencephalic small (MeS) neurons, form crucial synapses and the MeS neurons. The bilaterally-connecting neurons are expected send signals to the myotome (musculature of the spine). However, to be most crucial for fine-tuned tail deflection. The present presynaptic connections are not yet well understood. The present study reconstructed neurons forming n>3 synapses, but there are study aims to elucidate the presynaptic neurons (PSN) of the hundreds more neurons with n<2 that have yet to be reconstructed, MeS responsible for a fine-tuned motor swim in zebrafish. Using making way for future research to fully elucidate these fine motor electron microscopy (EM) volume of the whole zebrafish, neurons control systems, possibly shining light into the humans’ fine motor in a whole brain can be reconstructed in a 3D space, which allows control system as well. us to identify the phenotypic parts of the neuron, such as dendritic, Examining the Role of Serotonergic Systems in Behavioral State Transitions in Larval Zebrafish Ayaan Ahmad, Marc Duque Ramirez, Mariela Petkova Harvard College | Dunster House | Applied Math | 2028 Larval zebrafish exhibit a behavioral switch from active struggle toircuits are involved in behavioral state transitions. In our project, passivity when their efforts are futile—a state-switching behavior we reconstructed more than 60 neurons in the superior dorsal raphe analogous to learned helplessness. Previous studies show that nucleus (sDRN) of a zebrafish using electron microscopy data. this behavioral switch is modulated by noradrenergic circuits We identified the projections and inputs of these raphe neurons, that activate radial astrocytes, ultimately encoding a “failure” classified them by neurotransmitter identity (e.g., serotonergic, signal for the fish. However, studies in zebrafish and mammals GABAergic, glutamatergic) according to their projection patterns, suggest that serotonergic neurons in the dorsal raphe nucleus and investigated whether they interact with noradrenergic systems (DRN) may encode an opposing “success” signal and contribute such as the locus coeruleus (LC) or the norepinephrine cluster to behavioral persistence. This project aims to clarify how of the medulla oblongata (NE-MO). Ultimately, we found that serotonergic circuits in the dorsal raphe nucleus of a zebrafish serotonergic circuits may contribute to behavioral state transitions interact with the noradrenergic circuits, and to confirm if these and antidepressant effects. Summer Humanities and Arts Research Program 162 Summer Humanities and Arts Research Program #HarvardLore: Tradition as Rhetoric and Process at Harvard University Giselle Acosta, Sarah Craycraft Harvard College | Lowell House | Folklore and Mythology | 2027 This project is part of a larger HarvardLore initiative that studiesccompanied, and succeeded by an outpouring of rhetoric that how traditional expressive culture defines and reshapes belonging attempted to redefine (or reinforce) the Harvard student body, at Harvard. Inspired by ongoing campus protests around the Gaza Harvard administration, and their obligations to each other and the conflict, this project analyzed the significance of protest folklore,tside world. Other ephemera from the event indicate that folk specifically how folk arts negotiate communal identity in times of artslikefashionandcomicsprovidedfuelforthecompetingcamps’ civil unrest. To accomplish this goal, the author used the mass rhetoric as they tried to reconcile the everyday at Harvard with protests at Harvard in April of 1969 as a case study. According to social justice issues like classism and the Vietnam War. Studying contemporary local and student publications, hundreds of student the 1969 Harvard protests thus offers insight into how folklore can activists occupied University Hall, were violently evicted by be weaponized for or against radical change-makers on college police, then conducted an eight-day strike involving thousands of campuses and beyond. Harvard students and teaching staff. These acts were preceded,

Abstract:

The neural circuitry of interoception, or the sensing and regulation neurotransmitter profile, emerged. One subtype is excitatory, with of internal bodily states, remains poorly understood. To address somas originating in the nucleus of the solitary tract (NTS) and thisgap, weareusingconnectomicanalysisofelectronmicroscopy exclusively ipsilaterally projecting axons. The second subtype, images from a 7-day-old larval zebrafish, aiming to identify neural with somas located more broadly through the hindbrain, has patterns of connectivity between the sensory and motor elements axons which extend both ipsi- and contralaterally. Its anatomical of the vagus nerve. This nerve carries information bidirectionally features and absence of GABAergic or glutamatergic markers between the brain and various organs, including the heart, the point to this subtype releasing glycine, a dominantly inhibitory digestive system, and the pharynx, implying that the vagus nerve neurotransmitter. We hypothesize that these subtypes represent a is a primary mediator of interoception for these systems. Our system of large-scale inhibition paired with localized excitation. project focuses on the pharynx, an organ that contains a diverse This is a common motif in sensory systems (e.g. vision or array of structures in zebrafish, from gills and muscle cells to tastelfaction), increasing contrast between sensory inputs and refining buds. We traced all pharyngeal-projecting vagal motor neurons motor output. It can also help control background noise, which is back to their somata in the hindbrain, along with every presynaptic especially important in the context of a developing animal. Further interneurontothesemotorcells. Weplantofollowthisbymapping research is needed to determine whether this or another circuit the broader network of upstream and downstream connections. architecture regulate pharyngeal interoception in the vagus nerve. Two distinct classes of interneurons, differing in anatomy and Steeringthe Zebrafish: ElucidatingthePresynapticConnectionsofthenMLF Benjamin Selip, Yasuko Isoe, Mariela Petkova Brandeis University | Neuroscience | 2028 Motor control is essential for animals to govern their movements somatic, andaxoniclocationsandsynapticconnections. Currently, and is categorized into rough and fine motor control. Fine motor we focused on four lateral MeS (MeSL1-4) and identified 48 PSNs control is critical for more accurate movements, such as target- for MeSL1, 37 PSNs for MeSL2, 20 PSNs for MeSL3, and 13 gazing eye movements or calligraphy. The circuitry behind fine PSNs for MeSL4. Most PSNs were located in the ipsi- or contra- motor control remains unknown. Previous studies found that a lateral nMLF region with dendrites in the respective intermediate region of the midbrain called the nucleus of Medial Longitudinal hypothalamus and axons extending bilaterally. Spinal neurons Fasciculus (nMLF) is associated with this fine motor movement. were also found, extending axons up into the midbrain. Neurons Zebrafish studies found that a subpopulation within the nMLF, found within the cerebellum and optic areas formed synapses with mesencephalic small (MeS) neurons, form crucial synapses and the MeS neurons. The bilaterally-connecting neurons are expected send signals to the myotome (musculature of the spine). However, to be most crucial for fine-tuned tail deflection. The present presynaptic connections are not yet well understood. The present study reconstructed neurons forming n>3 synapses, but there are study aims to elucidate the presynaptic neurons (PSN) of the hundreds more neurons with n<2 that have yet to be reconstructed, MeS responsible for a fine-tuned motor swim in zebrafish. Using making way for future research to fully elucidate these fine motor electron microscopy (EM) volume of the whole zebrafish, neurons control systems, possibly shining light into the humans’ fine motor in a whole brain can be reconstructed in a 3D space, which allows control system as well. us to identify the phenotypic parts of the neuron, such as dendritic, Examining the Role of Serotonergic Systems in Behavioral State Transitions in Larval Zebrafish Ayaan Ahmad, Marc Duque Ramirez, Mariela Petkova Harvard College | Dunster House | Applied Math | 2028 Larval zebrafish exhibit a behavioral switch from active struggle toircuits are involved in behavioral state transitions. In our project, passivity when their efforts are futile—a state-switching behavior we reconstructed more than 60 neurons in the superior dorsal raphe analogous to learned helplessness. Previous studies show that nucleus (sDRN) of a zebrafish using electron microscopy data. this behavioral switch is modulated by noradrenergic circuits We identified the projections and inputs of these raphe neurons, that activate radial astrocytes, ultimately encoding a “failure” classified them by neurotransmitter identity (e.g., serotonergic, signal for the fish. However, studies in zebrafish and mammals GABAergic, glutamatergic) according to their projection patterns, suggest that serotonergic neurons in the dorsal raphe nucleus and investigated whether they interact with noradrenergic systems (DRN) may encode an opposing “success” signal and contribute such as the locus coeruleus (LC) or the norepinephrine cluster to behavioral persistence. This project aims to clarify how of the medulla oblongata (NE-MO). Ultimately, we found that serotonergic circuits in the dorsal raphe nucleus of a zebrafish serotonergic circuits may contribute to behavioral state transitions interact with the noradrenergic circuits, and to confirm if these and antidepressant effects. Summer Humanities and Arts Research Program 162 Summer Humanities and Arts Research Program #HarvardLore: Tradition as Rhetoric and Process at Harvard University Giselle Acosta, Sarah Craycraft Harvard College | Lowell House | Folklore and Mythology | 2027 This project is part of a larger HarvardLore initiative that studiesccompanied, and succeeded by an outpouring of rhetoric that how traditional expressive culture defines and reshapes belonging attempted to redefine (or reinforce) the Harvard student body, at Harvard. Inspired by ongoing campus protests around the Gaza Harvard administration, and their obligations to each other and the conflict, this project analyzed the significance of protest folklore,tside world. Other ephemera from the event indicate that folk specifically how folk arts negotiate communal identity in times of artslikefashionandcomicsprovidedfuelforthecompetingcamps’ civil unrest. To accomplish this goal, the author used the mass rhetoric as they tried to reconcile the everyday at Harvard with protests at Harvard in April of 1969 as a case study. According to social justice issues like classism and the Vietnam War. Studying contemporary local and student publications, hundreds of student the 1969 Harvard protests thus offers insight into how folklore can activists occupied University Hall, were violently evicted by be weaponized for or against radical change-makers on college police, then conducted an eight-day strike involving thousands of campuses and beyond. Harvard students and teaching staff. These acts were preceded,

Source:

Harvard / Brandeis University | Neuroscience | 2028 / 2025

Topics:

neuron, zebrafish, motor, system, fine, control, behavioral, state, nucleu, circuit, psns, found

Co-authors:

@zoeschurman441 , @kristianherrera442 , @marielapetkova437 , @florianengert326