4 results on '"James P Clement"'
Search Results
2. SRF-deficient astrocytes provide neuroprotection in mouse models of excitotoxicity and neurodegeneration
- Author
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Surya Chandra Rao Thumu, Monika Jain, Sumitha Soman, Soumen Das, Vijaya Verma, Arnab Nandi, David H Gutmann, Balaji Jayaprakash, Deepak Nair, James P Clement, Swananda Marathe, and Narendrakumar Ramanan
- Subjects
astrocytes ,reactive astrocytes ,astrogliosis ,SRF ,serum response factor ,neuroprotection ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Reactive astrogliosis is a common pathological hallmark of CNS injury, infection, and neurodegeneration, where reactive astrocytes can be protective or detrimental to normal brain functions. Currently, the mechanisms regulating neuroprotective astrocytes and the extent of neuroprotection are poorly understood. Here, we report that conditional deletion of serum response factor (SRF) in adult astrocytes causes reactive-like hypertrophic astrocytes throughout the mouse brain. These SrfGFAP-ERCKO astrocytes do not affect neuron survival, synapse numbers, synaptic plasticity or learning and memory. However, the brains of Srf knockout mice exhibited neuroprotection against kainic-acid induced excitotoxic cell death. Relevant to human neurodegenerative diseases, SrfGFAP-ERCKO astrocytes abrogate nigral dopaminergic neuron death and reduce β-amyloid plaques in mouse models of Parkinson’s and Alzheimer’s disease, respectively. Taken together, these findings establish SRF as a key molecular switch for the generation of reactive astrocytes with neuroprotective functions that attenuate neuronal injury in the setting of neurodegenerative diseases.
- Published
- 2024
- Full Text
- View/download PDF
3. Chronic postnatal chemogenetic activation of forebrain excitatory neurons evokes persistent changes in mood behavior
- Author
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Sthitapranjya Pati, Kamal Saba, Sonali S Salvi, Praachi Tiwari, Pratik R Chaudhari, Vijaya Verma, Sourish Mukhopadhyay, Darshana Kapri, Shital Suryavanshi, James P Clement, Anant B Patel, and Vidita A Vaidya
- Subjects
DREADD ,anxiety ,despair ,schizophrenia ,early stress ,mouse ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Early adversity is a risk factor for the development of adult psychopathology. Common across multiple rodent models of early adversity is increased signaling via forebrain Gq-coupled neurotransmitter receptors. We addressed whether enhanced Gq-mediated signaling in forebrain excitatory neurons during postnatal life can evoke persistent mood-related behavioral changes. Excitatory hM3Dq DREADD-mediated chemogenetic activation of forebrain excitatory neurons during postnatal life (P2–14), but not in juvenile or adult windows, increased anxiety-, despair-, and schizophrenia-like behavior in adulthood. This was accompanied by an enhanced metabolic rate of cortical and hippocampal glutamatergic and GABAergic neurons. Furthermore, we observed reduced activity and plasticity-associated marker expression, and perturbed excitatory/inhibitory currents in the hippocampus. These results indicate that Gq-signaling-mediated activation of forebrain excitatory neurons during the critical postnatal window is sufficient to program altered mood-related behavior, as well as functional changes in forebrain glutamate and GABA systems, recapitulating aspects of the consequences of early adversity.
- Published
- 2020
- Full Text
- View/download PDF
4. Chronic postnatal chemogenetic activation of forebrain excitatory neurons evokes persistent changes in mood behavior
- Author
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Kamal Saba, Darshana Kapri, Anant B. Patel, Sthitapranjya Pati, Sourish Mukhopadhyay, Vidita A. Vaidya, Vijaya Verma, Pratik R. Chaudhari, Sonali S. Salvi, Praachi Tiwari, Shital Suryavanshi, and James P. Clement
- Subjects
Male ,0301 basic medicine ,QH301-705.5 ,Science ,Hippocampus ,Biology ,Inhibitory postsynaptic potential ,General Biochemistry, Genetics and Molecular Biology ,Receptors, G-Protein-Coupled ,Mice ,03 medical and health sciences ,Glutamatergic ,Prosencephalon ,0302 clinical medicine ,Neurotransmitter receptor ,Animals ,GABAergic Neurons ,Biology (General) ,mouse ,Neurons ,despair ,Behavior, Animal ,General Immunology and Microbiology ,General Neuroscience ,Glutamate receptor ,General Medicine ,anxiety ,schizophrenia ,Affect ,030104 developmental biology ,Animals, Newborn ,nervous system ,early stress ,Forebrain ,Excitatory postsynaptic potential ,DREADD ,GABAergic ,Medicine ,Female ,Neuroscience ,030217 neurology & neurosurgery ,Research Article - Abstract
Early adversity is a risk factor for the development of adult psychopathology. Common across multiple rodent models of early adversity is increased signaling via forebrain Gq-coupled neurotransmitter receptors. We addressed whether enhanced Gq-mediated signaling in forebrain excitatory neurons during postnatal life can evoke persistent mood-related behavioral changes. Excitatory hM3Dq DREADD-mediated chemogenetic activation of forebrain excitatory neurons during postnatal life (P2–14), but not in juvenile or adult windows, increased anxiety-, despair-, and schizophrenia-like behavior in adulthood. This was accompanied by an enhanced metabolic rate of cortical and hippocampal glutamatergic and GABAergic neurons. Furthermore, we observed reduced activity and plasticity-associated marker expression, and perturbed excitatory/inhibitory currents in the hippocampus. These results indicate that Gq-signaling-mediated activation of forebrain excitatory neurons during the critical postnatal window is sufficient to program altered mood-related behavior, as well as functional changes in forebrain glutamate and GABA systems, recapitulating aspects of the consequences of early adversity., eLife digest Stress and adversity in early childhood can have long-lasting effects, predisposing people to mental illness and mood disorders in adult life. The weeks immediately before and after birth are critical for establishing key networks of neurons in the brain. Therefore, any disruption to these neural circuits during this time can be detrimental to emotional development. However, it is still unclear which cellular mechanisms cause these lasting changes in behavior. Studies in animals suggest that these long-term effects could result from abnormalities in a few signaling pathways in the brain. For example, it has been proposed that overstimulating the cells that activate circuits in the forebrain – also known as excitatory neurons – may contribute to the behavioral changes that persist into adulthood. To test this theory, Pati et al. used genetic engineering to modulate a signaling pathway in male mice, which is known to stimulate excitatory neurons in the forebrain. The experiments showed that prolonged activation of excitatory neurons in the first two weeks after birth resulted in anxious and despair-like behaviors as the animals aged. The mice also displayed discrepancies in how they responded to certain external sensory information, which is a hallmark of schizophrenia-like behavior. However, engineering the same changes in adolescent and adult mice had no effect on their mood-related behaviors. This animal study reinforces just how critical the first few weeks of life are for optimal brain development. It provides an insight into a possible mechanism of how disruption during this time could alter emotional behavior. The findings are also relevant to psychiatrists interested in the underlying causes of mental illness after early childhood adversity.
- Published
- 2020
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