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Partial blocking of NMDA receptors restricts plastic changes in adult mouse barrel cortex
B Jabłońska1, M Gierdalski, E Siucińska
1Department of Neurophysiology, Nencki Institute, Warsaw, Poland.
Abstract:
Changes of cortical body maps can be evoked in brains of adult animals by injury to sensory nerves. We investigated changes of functional representation of row C of mystacial vibrissae in the barrel cortex of mice. Plastic changes of cortical representations were mapped with 2-deoxyglucose autoradiography. Seven days after lesions of all vibrissae except row C, cortical representation of the spared row increased in width by 60%. Partial blocking of N-methyl-D-aspartate (NMDA) receptors by subdural implants of thin sheets of Elvax impregnated with DL-2-amino-5-phosphonovaleric acid (APV) prevented development of the increase of row C representation. Low level of NMDA receptor blocking did not affect significantly the basal level of 2DG uptake and stimulus evoked uptake but prevented the plastic change of the body map.
Insights
Sensory nerve injury alters brain maps. Blocking N-methyl-D-aspartate (NMDA) receptors prevented the expansion of cortical representations in mice, indicating their role in this brain plasticity.
Area of Science:
- Neuroscience
- Neuroplasticity
- Sensory Systems
Background:
- Adult brains exhibit plasticity, altering cortical body maps after sensory nerve injury.
- The barrel cortex in mice processes sensory information from mystacial vibrissae (whiskers).
Purpose of the Study:
- To investigate functional changes in the mouse barrel cortex representation of specific vibrissae after nerve injury.
- To determine the role of N-methyl-D-aspartate (NMDA) receptors in experience-dependent cortical plasticity.
Main Methods:
- Utilized 2-deoxyglucose (2DG) autoradiography to map functional cortical representations.
- Induced plasticity by lesioning all mystacial vibrissae except for row C.
- Administered DL-2-amino-5-phosphonovaleric acid (APV) to partially block NMDA receptors via subdural implants.
Main Results:
- Lesioning of all vibrissae except row C led to a 60% increase in the cortical representation of the spared row C vibrissae.
- Partial blockade of NMDA receptors with APV prevented this expansion of the cortical representation.
- Low-level NMDA receptor blockade did not significantly alter basal or stimulus-evoked 2DG uptake.
Conclusions:
- NMDA receptors are crucial for the experience-dependent expansion of cortical body maps following sensory nerve injury.
- This study highlights the role of NMDA receptor-mediated synaptic plasticity in reorganizing sensory cortical representations.