Related Experiment Videos
Immature cortex lesions alter retinotopic maps and interhemispheric connections
C Ernesto Restrepo1, Paul R Manger, Christian Spenger
1Division of Neuroanatomy and Brain Development, Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden. giorgio.innocenti@neuro.ki.se
Annals of Neurology
|July 3, 2003
Summary
Early ferret brain lesions to visual cortex do not create new visual responses. Instead, remaining visual areas show abnormal organization, and connections are rewired, impacting brain plasticity.
Area of Science:
- Neuroscience
- Developmental Neuroscience
- Visual Cortex Plasticity
Background:
- Early-onset lesions in the occipital visual areas can impact brain development and function.
- Understanding the brain's capacity for structural plasticity is crucial for predicting outcomes of early-onset injuries.
Purpose of the Study:
- To investigate the structural and functional consequences of unilateral occipital visual cortex lesions in ferrets at postnatal day 5 (P5).
- To determine the limits of developmental plasticity in the visual cortex regarding retinotopy and connectivity.
Main Methods:
- Unilateral lesions of occipital visual areas were induced in ferrets on postnatal day 5 (P5).
- Retinotopic mapping and analysis of callosal connections were performed in lesioned and intact hemispheres.
Main Results:
- Lesions did not induce ectopic visual responses; spared visual areas exhibited abnormal retinotopy and callosal connections.
- Complete lesions, including the posterior parietal cortex, led to aberrant somatosensory to parietal cortex callosal connections.
- The intact hemisphere's visual areas maintained normal retinotopy but lost homotopic callosal connections.
Conclusions:
- Certain cortical regions are irreversibly allocated to visual areas early in life.
- Retinotopy and connectivity within the visual cortex remain modifiable despite early allocation.
- Findings offer insights into the consequences of early-onset visual cortical lesions in humans.