Is the development of orientation selectivity instructed by activity?

Area of Science:

• Neuroscience
• Developmental Biology
• Visual System

Background:

• The development of orientation selectivity in the visual cortex is crucial for visual processing.
• Understanding the role of neural activity in this developmental process is a key question in neuroscience.

Purpose of the Study:

• To review evidence and models concerning the role of neural activity in the development of orientation selectivity.
• To discuss how current models of activity-instructed development can be experimentally tested.
• To critically examine alternative developmental scenarios, including genetic prespecification.

Main Methods:

• Review of existing experimental evidence and theoretical models of visual cortex development.
• Analysis of experiments involving monocular deprivation and selective blockade of ON-center ganglion cells.
• Examination of spontaneous neural activity correlations in the lateral geniculate nucleus.

Main Results:

• Activity-instructed development models explain normal development of orientation selectivity and binocular matching.
• Experiments show that blocking specific neural inputs prevents orientation selectivity development.
• Spontaneous activity in inputs to the two eyes is correlated during critical developmental periods.

Conclusions:

• Existing evidence supports a role for neural activity in instructing orientation selectivity development.
• Definitive experiments are required to confirm the instructive, rather than permissive, role of activity patterns.
• Further research is needed to verify predicted activity patterns and rule out genetic prespecification.