1
|
Napoli AJ, Laderwager S, Zoodsma JD, Biju B, Mucollari O, Schubel SK, Aprea C, Sayed A, Morgan K, Napoli A, Flanagan S, Wollmuth LP, Sirotkin HI. Developmental loss of NMDA receptors results in supernumerary forebrain neurons through delayed maturation of transit-amplifying neuroblasts. Sci Rep 2024; 14:3395. [PMID: 38336823 PMCID: PMC10858180 DOI: 10.1038/s41598-024-53910-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 02/06/2024] [Indexed: 02/12/2024] Open
Abstract
Developmental neurogenesis is a tightly regulated spatiotemporal process with its dysregulation implicated in neurodevelopmental disorders. NMDA receptors are glutamate-gated ion channels that are widely expressed in the early nervous system, yet their contribution to neurogenesis is poorly understood. Notably, a variety of mutations in genes encoding NMDA receptor subunits are associated with neurodevelopmental disorders. To rigorously define the role of NMDA receptors in developmental neurogenesis, we used a mutant zebrafish line (grin1-/-) that lacks all NMDA receptors yet survives to 10 days post-fertilization, offering the opportunity to study post-embryonic neurodevelopment in the absence of NMDA receptors. Focusing on the forebrain, we find that these fish have a progressive supernumerary neuron phenotype confined to the telencephalon at the end of embryonic neurogenesis, but which extends to all forebrain regions during postembryonic neurogenesis. This enhanced neuron population does not arise directly from increased numbers or mitotic activity of radial glia cells, the principal neural stem cells. Rather, it stems from a lack of timely maturation of transit-amplifying neuroblasts into post-mitotic neurons, as indicated by a decrease in expression of the ontogenetically-expressed chloride transporter, KCC2. Pharmacological blockade with MK-801 recapitulates the grin1-/- supernumerary neuron phenotype, indicating a requirement for ionotropic signaling. Thus, NMDA receptors are required for suppression of indirect, transit amplifying cell-driven neurogenesis by promoting maturational termination of mitosis. Loss of suppression results in neuronal overpopulation that can fundamentally change brain circuitry and may be a key factor in pathogenesis of neurodevelopmental disorders caused by NMDA receptor dysfunction.
Collapse
Affiliation(s)
- Amalia J Napoli
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Stephanie Laderwager
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
- Graduate Program in Neuroscience, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Josiah D Zoodsma
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Bismi Biju
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Olgerta Mucollari
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Sarah K Schubel
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Christieann Aprea
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Aaliya Sayed
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Kiele Morgan
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Annelysia Napoli
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Stephanie Flanagan
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Lonnie P Wollmuth
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794-5215, USA
- Center for Nervous System Disorders, Stony Brook University, Stony Brook, NY, 11794-5230, USA
| | - Howard I Sirotkin
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, NY, 11794-5230, USA.
| |
Collapse
|
2
|
Napoli AJ, Laderwager S, Zoodsma JD, Biju B, Mucollari O, Schubel SK, Aprea C, Sayed A, Morgan K, Napoli A, Flanagan S, Wollmuth LP, Sirotkin HI. Loss of NMDA receptor function during development results in decreased KCC2 expression and increased neurons in the zebrafish forebrain. bioRxiv 2023:2023.08.25.554812. [PMID: 37786708 PMCID: PMC10541604 DOI: 10.1101/2023.08.25.554812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
Developmental neurogenesis is a tightly regulated spatiotemporal process with its dysregulation implicated in neurodevelopmental disorders. NMDA receptors are glutamate-gated ion channels that are widely expressed in the early nervous system, yet their contribution to neurogenesis is poorly understood. Notably, a variety of mutations in genes encoding NMDA receptor subunits are associated with neurodevelopmental disorders. To rigorously define the role of NMDA receptors in developmental neurogenesis, we used a mutant zebrafish line ( grin1 -/- ) that lacks all NMDA receptors yet survives to 10 days post-fertilization, offering the opportunity to study post-embryonic neurodevelopment in the absence of NMDA receptors. Focusing on the forebrain, we find that these fish have a progressive supernumerary neuron phenotype confined to the telencephalon at the end of embryonic neurogenesis, but which extends to all forebrain regions during postembryonic neurogenesis. This enhanced neuron population does not arise directly from increased numbers or mitotic activity of radial glia cells, the principal neural stem cells. Rather, it stems from a lack of timely maturation of transit-amplifying neuroblasts into post-mitotic neurons, as indicated by a decrease in expression of the ontogenetically-expressed chloride transporter, KCC2. Pharmacological blockade with MK-801 recapitulates the grin1 -/- supernumerary neuron phenotype, indicating a requirement for ionotropic signaling. Thus, NMDA receptors are required for suppression of indirect, transit amplifying cell-driven neurogenesis by promoting maturational termination of mitosis. Loss of suppression results in neuronal overpopulation that can fundamentally change brain circuitry and may be a key factor in pathogenesis of neurodevelopmental disorders caused by NMDA receptor dysfunction.
Collapse
|