Protein kinase C immunoreactivity in kitten visual cortex is developmentally regulated and input-dependent.

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Biology

Background:

• Protein kinase C (PKC) plays a crucial role in neuronal function and plasticity.
• Visual cortex development is a critical period for sensory experience-dependent maturation.
• Understanding the regulation of PKC during development is essential for comprehending visual system plasticity.

Purpose of the Study:

• To investigate the developmental expression and regulation of protein kinase C (PKC) in kitten visual cortex neurons.
• To determine the influence of neuronal activity and visual experience on PKC localization and levels during early postnatal development.

Main Methods:

• Immunocytochemistry using polyclonal antibodies against protein kinase C (PKC).
• Analysis of PKC immunoreactivity in kitten visual cortex at various postnatal ages.
• Experimental manipulation involving isolation of cortical tissue from neuronal inputs.

Main Results:

• PKC was found at postsynaptic sites throughout development.
• Presynaptic PKC localization was transient, observed only during the first few weeks of postnatal life.
• Overall PKC immunoreactivity was high in early postnatal stages, declining with age, particularly in specific cortical layers.
• Input deprivation abolished the decline in PKC immunoreactivity in most cortical layers, suggesting a use-dependent regulation.
• The lateral geniculate nucleus is implicated as a source of input influencing PKC maturation.

Conclusions:

• PKC expression in the kitten visual cortex is both developmentally programmed and influenced by neuronal activity (use-dependent).
• Visual experience and neuronal input are critical for the normal maturational changes in PKC levels and localization.
• These findings highlight the dynamic nature of molecular signaling during critical periods of sensory system development.