Metaplasticity in the Visual Cortex: Crosstalk Between Visual Experience and Reactive Oxygen Species

• Published in: The Journal of neuroscience Vol. 38; no. 25; pp. 5649 - 5665
• Main Authors: Francis-Oliveira, José, Vilar Higa, Guilherme S, Mendonça Munhoz Dati, Lívia, Carvalho Shieh, Ianê, De Pasquale, Roberto
• Format: Journal Article
• Language: English
• Published: United States Society for Neuroscience 20-06-2018
• Subjects: Animals; Crosstalk; CYBB protein; Female; Glutamic acid receptors (ionotropic); Intracellular signalling; Long-term potentiation; Male; Mice; Mice, Inbred C57BL; Molecular structure; N-Methyl-D-aspartic acid receptors; NADPH Oxidase 2 - metabolism; Neural plasticity; Neuronal Plasticity - physiology; Plasticity; Reactive oxygen species; Reactive Oxygen Species - metabolism; Synaptic plasticity; Visual aspects; Visual cortex; Visual Cortex - physiology; Visual observation; Visual plasticity; dark rearing; NMDA receptor; visual cortex; metaplasticity; ROS; NOX2
• ISSN: 0270-6474; 1529-2401
• DOI: 10.1523/JNEUROSCI.2617-17.2018

Metaplasticity is the regulation of synaptic plasticity based on the history of previous synaptic activation. This concept was formulated after observing that synaptic changes in the visual cortex are not fixed, but dynamic and dependent on the history of visual information flux. In visual cortical neurons, sustained synaptic stimulation activate the enzymatic complex NOX2, resulting in the generation of reactive oxygen species (ROS). NOX2 is the main molecular structure responsible for translating neural activity into redox modulation of intracellular signaling pathways involved in plastic changes. Here, we studied the interaction between NOX2 and visual experience as metaplastic factors regulating synaptic plasticity at the supergranular layers of the mouse visual cortex. We found that genetic inhibition of NOX2 reverses the polarizing effects of dark rearing from LTP to LTD. In addition, we demonstrate that this process relies on changes in the NMDA receptor functioning. Altogether, this work indicates a role of ROS in the activity-dependent regulation of cortical synaptic plasticity.
Synaptic plasticity in the visual cortex is modulated by the history of sensory experience and this modulation has been defined as metaplasticity. Dark rearing facilitates synaptic potentiation as a mechanism optimizing the range of synaptic modification. This process requires the production of reactive oxygen species mediated by the enzymatic complex NOX2. If the activity of NOX2 is inhibited, then visual deprivation results in synaptic depression. These findings increase our knowledge about metaplasticity and help in our understanding of how neural activity modulates cellular mechanisms of synaptic change.