|Title||Metaplasticity governs natural experience-driven plasticity of nascent embryonic brain circuits.|
|Publication Type||Journal Article|
|Year of Publication||2009|
|Authors||Dunfield D, Haas K|
|Date Published||2009 Oct 29|
|Keywords||2-Amino-5-phosphonovalerate, Action Potentials, Animals, Behavior, Animal, Biophysics, Brain, Calcium, Electric Stimulation, Excitatory Amino Acid Antagonists, Long-Term Potentiation, Models, Neurological, Nerve Net, Neurons, Photic Stimulation, Statistics as Topic, Superior Colliculi, Synapses, Visual Pathways, Xenopus laevis|
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.
|Grant List||/ / Canadian Institutes of Health Research / Canada|