title: Metaplasticity governs natural experience-driven plasticity of nascent embryonic brain circuits.
abstract: During embryogenesis, brain neurons receiving the same sensory input may undergo potentiation or depression. While the origin of variable plasticity in vivo is unknown, it plays a key role in shaping dynamic neural circuit refinement. Here, we investigate effects of natural visual stimuli on neuronal firing within the intact, awake, developing brain using calcium imaging of 100 s of central neurons in the Xenopus retinotectal system. We find that specific patterns of visual stimuli shift population responses toward either potentiation or depression in an N-methyl-D-aspartate receptor (NMDA-R)-dependent manner. In agreement with Bienenstock-Cooper-Munro metaplasticity, our results show that functional potentiation or depression can be predicted by individual neurons' specific receptive field properties and historic firing rates. Interestingly, this activity-dependent metaplasticity is itself NMDA-R dependent. Furthermore, network analysis reveals increased correlated firing of neurons that undergo potentiation. These findings implicate metaplasticity as a natural property regulating experience-dependent refinement of nascent embryonic brain circuits.
authors.affiliation: Department of Cellular and Physiological Sciences and the Brain Research Centre, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Derek
authors.initials: D
authors.lastname: Dunfield
authors.forename: Kurt
authors.initials: K
authors.lastname: Haas
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001522:Behavior, Animal; D001703:Biophysics; D001921:Brain / Q000033:anatomy & histology* / Q000196:embryology; D002118:Calcium / Q000378:metabolism; D004558:Electric Stimulation / Q000379:methods; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008959:Models, Neurological; D009415:Nerve Net / Q000166:cytology* / Q000196:embryology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D013223:Statistics as Topic; D013477:Superior Colliculi / Q000166:cytology / Q000196:embryology; D013569:Synapses / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology; D014982:Xenopus laevis
chemical_list: D018691:Excitatory Amino Acid Antagonists; D015763:2-Amino-5-phosphonovalerate; D002118:Calcium