Mismatch between BDNF mRNA and protein expression in the developing visual cortex: the role of visual experience

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Biology

Background:

• Brain-derived neurotrophic factor (BDNF) is vital for neuronal development and function.
• BDNF expression is known to be developmentally regulated and influenced by sensory experience.
• The relationship between BDNF mRNA and protein during visual cortex development and the role of visual activity remain unclear.

Purpose of the Study:

• To compare BDNF mRNA and protein expression during postnatal development in the rat visual cortex.
• To investigate whether visual activity controls BDNF protein distribution.
• To elucidate the impact of visual deprivation and light exposure on BDNF expression.

Main Methods:

• Immunohistochemistry and in situ hybridization were used to analyze BDNF mRNA and protein distribution.
• Studies were conducted on rat visual cortex at different postnatal ages (P13, P23, P90).
• Visual experience was manipulated through dark rearing and brief light exposure.

Main Results:

• Before eye opening (P13), neurons express BDNF mRNA but not detectable BDNF protein.
• Postnatally (P23, P90), BDNF protein expression increases, with most neurons showing both mRNA and protein.
• Visual deprivation blocks BDNF protein increase, while light exposure restores the mRNA-protein match.

Conclusions:

• Visual experience is a critical regulator of both BDNF mRNA and protein levels in the developing visual cortex.
• The transition from BDNF mRNA to protein requires visual input.
• This study highlights the plasticity of neurotrophin expression in response to sensory experience.