12 results on '"Sue Junn"'
Search Results
2. Supramammillary neurons projecting to the septum regulate dopamine and motivation for environmental interaction in mice
- Author
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Andrew J. Kesner, Rick Shin, Coleman B. Calva, Reuben F. Don, Sue Junn, Christian T. Potter, Leslie A. Ramsey, Ahmed F. Abou-Elnaga, Christopher G. Cover, Dong V. Wang, Hanbing Lu, Yihong Yang, and Satoshi Ikemoto
- Subjects
Science - Abstract
The supramammillary region (SuM) regulates arousal that reinforces and energizes behavioral interaction with the environment. Here the authors investigate how SuM neurons interact with medial septal neurons and ventral tegmental dopamine neurons to regulate motivation for environmental interaction.
- Published
- 2021
- Full Text
- View/download PDF
3. Early postnatal exposure to isoflurane causes cognitive deficits and disrupts development of newborn hippocampal neurons via activation of the mTOR pathway.
- Author
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Eunchai Kang, Danye Jiang, Yun Kyoung Ryu, Sanghee Lim, Minhye Kwak, Christy D Gray, Michael Xu, Jun H Choi, Sue Junn, Jieun Kim, Jing Xu, Michele Schaefer, Roger A Johns, Hongjun Song, Guo-Li Ming, and C David Mintz
- Subjects
Biology (General) ,QH301-705.5 - Abstract
Clinical and preclinical studies indicate that early postnatal exposure to anesthetics can lead to lasting deficits in learning and other cognitive processes. The mechanism underlying this phenomenon has not been clarified and there is no treatment currently available. Recent evidence suggests that anesthetics might cause persistent deficits in cognitive function by disrupting key events in brain development. The hippocampus, a brain region that is critical for learning and memory, contains a large number of neurons that develop in the early postnatal period, which are thus vulnerable to perturbation by anesthetic exposure. Using an in vivo mouse model we demonstrate abnormal development of dendrite arbors and dendritic spines in newly generated dentate gyrus granule cell neurons of the hippocampus after a clinically relevant isoflurane anesthesia exposure conducted at an early postnatal age. Furthermore, we find that isoflurane causes a sustained increase in activity in the mechanistic target of rapamycin pathway, and that inhibition of this pathway with rapamycin not only reverses the observed changes in neuronal development, but also substantially improves performance on behavioral tasks of spatial learning and memory that are impaired by isoflurane exposure. We conclude that isoflurane disrupts the development of hippocampal neurons generated in the early postnatal period by activating a well-defined neurodevelopmental disease pathway and that this phenotype can be reversed by pharmacologic inhibition.
- Published
- 2017
- Full Text
- View/download PDF
4. Sensorimotor Outcomes in Pediatric Patients With Ocular Trauma in Baltimore
- Author
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Sue Junn, Courtney Pharr, Victoria Chen, Katherine Williams, Janet Alexander, Hee-Jung Park, Courtney Kraus, and Moran Roni Levin
- Subjects
Strabismus ,Ophthalmology ,Eye Injuries ,Trauma Severity Indices ,Baltimore ,Pediatrics, Perinatology and Child Health ,Vision Disorders ,Humans ,General Medicine ,Child ,Prognosis ,Eye Injuries, Penetrating ,Retrospective Studies - Abstract
Purpose: To evaluate sensorimotor outcomes following traumatic open globe injuries in the pediatric population. Methods: A retrospective cohort of 80 pediatric patients aged 0.4 to 17.7 years (mean age: 9.3 years, median age: 8.3 years) presenting with traumatic open globe injury to the Johns Hopkins and University of Maryland Medical Centers was evaluated between January 2006 and January 2020. Parameters included the mechanism of injury, length of time of visual deprivation, initial and final visual acuity, additional eye pathologies, and demographic factors such as age and sex. Results: Among children with more than 6 months of follow-up, 77.4% developed poor stereopsis and 50% developed strabismus. Children who developed strabismus had a lower Pediatric Ocular Trauma Score (POTS), indicating greater severity of injury, than children who did not develop strabismus ( P = .005, chi-square test). A higher POTS, indicating less severe ocular injury, significantly correlated to a better stereoacuity ( P = .001, chi-square test). Conclusions: The findings indicate that strabismus and poor stereopsis are common in pediatric open globe injuries, occurring in more than half of children with pediatric open globe trauma. These outcomes are associated with poor presenting visual acuity, more severe ocular trauma, and a lower presenting POTS. [ J Pediatr Ophthalmol & Strabismus . 2022;59(5):303–309.]
- Published
- 2022
5. Assessing the Effect of Telemedicine Implementation on Patient Satisfaction With and Adherence to Gynecologic Appointments [ID: 1344973]
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Sue Junn, Andrea Desai, Julie Hurvitz, and Elizabeth Lahti
- Subjects
Obstetrics and Gynecology - Published
- 2023
6. Supramammillary neurons projecting to the septum regulate dopamine and motivation for environmental interaction in mice
- Author
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Ahmed F. Abou-Elnaga, Leslie A. Ramsey, Yihong Yang, Dong V. Wang, Christopher G. Cover, Rick Shin, Satoshi Ikemoto, Christian T. Potter, Sue Junn, Andrew J. Kesner, Coleman B. Calva, Reuben F. Don, and Hanbing Lu
- Subjects
0301 basic medicine ,Male ,Hypothalamus, Posterior ,Dopamine ,Science ,Models, Neurological ,General Physics and Astronomy ,Glutamic Acid ,Stimulation ,Mesolimbic dopamine ,Mice, Transgenic ,Optogenetics ,Hippocampal formation ,General Biochemistry, Genetics and Molecular Biology ,Article ,Arousal ,03 medical and health sciences ,Glutamatergic ,Mice ,0302 clinical medicine ,Reward ,Neural Pathways ,medicine ,Animals ,Rats, Wistar ,alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid ,Motivation ,Multidisciplinary ,Behavior, Animal ,Chemistry ,Dopaminergic Neurons ,Ventral Tegmental Area ,General Chemistry ,Magnetic Resonance Imaging ,Rats ,Mice, Inbred C57BL ,030104 developmental biology ,nervous system ,Hypothalamic structure ,Female ,Septum of Brain ,Consummatory Behavior ,Neuroscience ,Reinforcement, Psychology ,030217 neurology & neurosurgery ,medicine.drug - Abstract
The supramammillary region (SuM) is a posterior hypothalamic structure, known to regulate hippocampal theta oscillations and arousal. However, recent studies reported that the stimulation of SuM neurons with neuroactive chemicals, including substances of abuse, is reinforcing. We conducted experiments to elucidate how SuM neurons mediate such effects. Using optogenetics, we found that the excitation of SuM glutamatergic (GLU) neurons was reinforcing in mice; this effect was relayed by their projections to septal GLU neurons. SuM neurons were active during exploration and approach behavior and diminished activity during sucrose consumption. Consistently, inhibition of SuM neurons disrupted approach responses, but not sucrose consumption. Such functions are similar to those of mesolimbic dopamine neurons. Indeed, the stimulation of SuM-to-septum GLU neurons and septum-to-ventral tegmental area (VTA) GLU neurons activated mesolimbic dopamine neurons. We propose that the supramammillo-septo-VTA pathway regulates arousal that reinforces and energizes behavioral interaction with the environment., The supramammillary region (SuM) regulates arousal that reinforces and energizes behavioral interaction with the environment. Here the authors investigate how SuM neurons interact with medial septal neurons and ventral tegmental dopamine neurons to regulate motivation for environmental interaction.
- Published
- 2021
7. Baltimore pediatric ocular trauma study: Health disparities and outcomes in pediatric and adolescent open globe trauma
- Author
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Victoria Chen, Courtney Pharr, Sue Junn, Courtney L. Kraus, Michael Fliotsos, Hee-Jung Park, Janet L. Alexander, Fasika Woreta, Gregory B. Carey, and Moran R. Levin
- Subjects
General Earth and Planetary Sciences ,General Environmental Science - Abstract
Purpose Children represent approximately one-third of patients with serious ocular injuries. Our study evaluates associations between race and socioeconomic status in presentation and outcomes of pediatric and adolescent traumatic open globe injuries. Methods We conducted a retrospective chart review of traumatic open globe injuries in pediatric and adolescent patients presenting to Johns Hopkins Hospital and University of Maryland Medical Center between 2006 and 2020. Variables assessed included age, gender, parent-identified race, median household income, mechanism of injury, initial and final visual acuity (VA), and length of follow-up. Results Eighty patients ranging from 4 months to 17.7 years (mean 9.3 years) presented with traumatic open globe injury. Identifications were 28 White (35%), 38 Black (48%), and 5 Hispanic (6%). Initial presenting and final VA, pediatric ocular trauma score (POTS), and length of follow-up did not differ significantly among race, gender, or income. Black patients had higher rates of blunt trauma (odds ratio (OR) 3.81; 95% confidence interval (CI) 0.95-15.24, p = 0.07), uveal prolapse (OR 3.58; 95% CI 1.03-12.43; p = 0.049), and enucleation (OR 10.55; 95% CI 1.26-88.31). Hispanic patients presented at a younger age of 2.8 years mean age vs. 9.9 years (p = 0.004) for others. Conclusion Visual outcomes following traumatic open globe injury were independent of race, gender, or income. However, blunt trauma, uveal prolapse, and enucleation rates were higher in Black patients, and ocular trauma occurred at a younger age in Hispanic patients.
- Published
- 2021
8. Early Developmental Exposure to Repetitive Long Duration of Midazolam Sedation Causes Behavioral and Synaptic Alterations in a Rodent Model of Neurodevelopment
- Author
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Shreya Singh, Sue Junn, Reilley P. Mathena, Ebony Blaize, Jane J. Long, Jing Xu, Qun Li, Jieun Kim, and Cyrus D. Mintz
- Subjects
Aging ,medicine.drug_class ,Developmental Disabilities ,Midazolam ,Neurogenesis ,Sedation ,Conscious Sedation ,Presynaptic Terminals ,Hippocampal formation ,Article ,Mice ,Intensive care ,medicine ,Animals ,Hypnotics and Sedatives ,Maze Learning ,Cells, Cultured ,Behavior, Animal ,business.industry ,Dentate gyrus ,Neurotoxicity ,Fear ,medicine.disease ,Mice, Inbred C57BL ,Anesthesiology and Pain Medicine ,Anesthesia ,Sedative ,Dentate Gyrus ,Synapses ,Anesthetic ,Surgery ,Neurology (clinical) ,medicine.symptom ,business ,medicine.drug - Abstract
There is a large body of preclinical literature suggesting that exposure to general anesthetic agents during early life may have harmful effects on brain development. Patients in intensive care settings are often treated for prolonged periods with sedative medications, many of which have mechanisms of action that are similar to general anesthetics. Using in vivo studies of the mouse hippocampus and an in vitro rat cortical neuron model we asked whether there is evidence that repeated, long duration exposure to midazolam, a commonly used sedative in pediatric intensive care practice, has the potential to cause lasting harm to the developing brain. We found that mice that underwent midazolam sedation in early postnatal life exhibited deficits in the performance on Y maze and fear conditioning testing at young adult ages. Labeling with a nucleoside analog revealed a reduction in the rate of adult neurogenesis in the hippocampal dentate gyrus, a brain region that has been shown to be vulnerable to developmental anesthetic neurotoxicity. Additionally, using immunohistochemistry for synaptic markers we found that the number of pre-synaptic terminals in the dentate gyrus was reduced, while the number of excitatory post-synaptic terminals was increased. These findings were replicated in a midazolam sedation exposure model in neurons in culture. We conclude that repeated, long duration exposure to midazolam during early development has the potential to result in persistent alterations in the structure and function of the brain.
- Published
- 2019
9. Medial Prefrontal Cortex Interacts with the Anteromedial Thalamus in Motivation and Dopaminergic Activity
- Author
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Pierce Af, Yihong Yang, Reuben F. Don, Sue Junn, Aleksandr D Talishinsky, Mejia-Aponte Ca, Hanbing Lu, Tan A, Coleman B. Calva, Leslie A. Ramsey, Céline Nicolas, Su C, Christian T. Potter, Dong V. Wang, Satoshi Ikemoto, Andrew J. Kesner, Yuzheng Hu, and Yang C
- Subjects
Dopaminergic ,Thalamus ,Stimulation ,Biology ,Midbrain ,nervous system ,Dopamine ,Excitatory postsynaptic potential ,medicine ,Reinforcement ,Prefrontal cortex ,Neuroscience ,psychological phenomena and processes ,medicine.drug - Abstract
How does the prefrontal cortex (PFC) regulate motivated behavior? Our experiments characterize the circuits of the PFC regulating motivation, reinforcement and dopamine activity, revealing a novel cortico-thalamic loop. The stimulation of medial PFC (mPFC) neurons activated many downstream regions, as shown by functional MRI. Axonal terminal stimulation of mPFC neurons in downstream regions, including the anteromedial thalamic nucleus (AM), reinforced behavior and activated midbrain dopaminergic neurons. The stimulation of AM neurons projecting to the mPFC also reinforced behavior and activated dopamine neurons, and mPFC and AM showed a positive-feedback loop organization. Reciprocal excitatory functional connectivity, as well as co-activation of the two regions, was found in human participants who watched reinforcing videos. Our results suggest that this cortico-thalamic loop regulates motivation, reinforcement and dopaminergic neuron activity.
- Published
- 2020
10. Supramammillary neurons projecting to the septum regulate dopamine and motivation for environmental interaction
- Author
-
Andrew J. Kesner, Reuben F. Don, Leslie A. Ramsey, Christian T. Potter, Sue Junn, Yihong Yang, Coleman B. Calva, Ahmed F. Abou-Elnaga, Rick Shin, Hanbing Lu, Dong V. Wang, Satoshi Ikemoto, and Christopher G. Cover
- Subjects
Glutamatergic ,nervous system ,Dopamine ,Chemistry ,medicine ,Hypothalamic structure ,Mesolimbic dopamine ,Stimulation ,Hippocampal formation ,Neuroscience ,Theta oscillations ,Arousal ,medicine.drug - Abstract
The supramammillary region (SuM) is a posterior hypothalamic structure, known to regulate hippocampal theta oscillations and arousal. However, recent studies reported that the stimulation of SuM neurons with neuroactive chemicals, including substances of abuse, is reinforcing. We conducted experiments to illuminate how SuM neurons mediate such effects. The excitation of SuM glutamatergic (GLU) neurons was reinforcing in mice; this effect was relayed by the projections to septal GLU neurons. SuM neurons were active during exploration and approach behavior and diminished activity during sucrose consumption. Consistently, inhibition of SuM neurons disrupted approach responses, but not sucrose consumption. Such functions are similar to those of mesolimbic dopamine neurons. Indeed, the stimulation of SuM-to-septum GLU neurons and septum-to-ventral tegmental area (VTA) GLU neurons activated mesolimbic dopamine neurons. We propose that the supramammillo-septo-VTA pathway is important in reinforcement and approach motivation and may play an important role in mood and substance-use disorders.
- Published
- 2020
11. The Baltimore Pediatric Ocular Trauma Study: sensorimotor outcomes following pediatric open globe injuries
- Author
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Courtney Pharr, Hee-Jung Park, Courtney L. Kraus, Moran Roni Levin, Sue Junn, and Janet L. Alexander
- Subjects
Ophthalmology ,medicine.medical_specialty ,Open globe ,business.industry ,Pediatrics, Perinatology and Child Health ,Emergency medicine ,Medicine ,Ocular trauma ,business - Published
- 2021
12. Early postnatal exposure to isoflurane causes cognitive deficits and disrupts development of newborn hippocampal neurons via activation of the mTOR pathway
- Author
-
Yun Kyoung Ryu, Jieun Kim, Minhye Kwak, Jun H. Choi, Danye Jiang, Sanghee Lim, Sue Junn, Roger A. Johns, Guo Li Ming, Hongjun Song, Jing Xu, Eunchai Kang, Christy D. Gray, Michele L. Schaefer, C. David Mintz, and Michael Xu
- Subjects
Dendritic spine ,QH301-705.5 ,Dendritic Spines ,Hippocampal formation ,Biology ,Hippocampus ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,Mice ,0302 clinical medicine ,030202 anesthesiology ,medicine ,Animals ,Cognitive Dysfunction ,Biology (General) ,PI3K/AKT/mTOR pathway ,Neurons ,General Immunology and Microbiology ,Isoflurane ,General Neuroscience ,Dentate gyrus ,TOR Serine-Threonine Kinases ,Correction ,Environmental exposure ,Environmental Exposure ,Granule cell ,3. Good health ,medicine.anatomical_structure ,Anesthetic ,Anesthetics, Inhalation ,General Agricultural and Biological Sciences ,Neuroscience ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Clinical and preclinical studies indicate that early postnatal exposure to anesthetics can lead to lasting deficits in learning and other cognitive processes. The mechanism underlying this phenomenon has not been clarified and there is no treatment currently available. Recent evidence suggests that anesthetics might cause persistent deficits in cognitive function by disrupting key events in brain development. The hippocampus, a brain region that is critical for learning and memory, contains a large number of neurons that develop in the early postnatal period, which are thus vulnerable to perturbation by anesthetic exposure. Using an in vivo mouse model we demonstrate abnormal development of dendrite arbors and dendritic spines in newly generated dentate gyrus granule cell neurons of the hippocampus after a clinically relevant isoflurane anesthesia exposure conducted at an early postnatal age. Furthermore, we find that isoflurane causes a sustained increase in activity in the mechanistic target of rapamycin pathway, and that inhibition of this pathway with rapamycin not only reverses the observed changes in neuronal development, but also substantially improves performance on behavioral tasks of spatial learning and memory that are impaired by isoflurane exposure. We conclude that isoflurane disrupts the development of hippocampal neurons generated in the early postnatal period by activating a well-defined neurodevelopmental disease pathway and that this phenotype can be reversed by pharmacologic inhibition.
- Published
- 2016
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