The neural cell adhesion molecule in synaptic plasticity and ageing

Area of Science:

• Neuroscience
• Molecular Biology
• Developmental Biology

Background:

• Neural cell adhesion molecule (NCAM) mediates cell adhesion and signal transduction, regulating neural development.
• NCAM plays a role in regeneration and learning in the adult nervous system.
• Polysialic acid (PSA) is a carbohydrate attached to NCAM, with expression levels changing during development and in response to stimuli.

Purpose of the Study:

• To explore the role of NCAM and PSA in learning and regeneration.
• To investigate the activity-dependent regulation of NCAM and PSA expression.
• To understand the functional significance of PSA-NCAM in the adult nervous system.

Main Methods:

• Studies involving NCAM-deficient mice to assess spatial learning.
• Intracranial injections of NCAM antibodies in rats and chicks to inhibit learning and long-term potentiation (LTP).
• Enzymatic removal of PSA to evaluate its impact on LTP and learning.
• Analysis of PSA-NCAM expression in muscle following denervation and in aging rats.

Main Results:

• NCAM-deficient mice exhibit impaired spatial learning.
• Inhibition of NCAM function and enzymatic removal of PSA both impair LTP and learning.
• PSA-NCAM expression is upregulated in specific brain areas, like the hippocampus, after learning.
• PSA-NCAM expression is upregulated in muscle after denervation, but this response diminishes with age.

Conclusions:

• NCAM and PSA are critical for learning and neural regeneration.
• Neuronal activity regulates NCAM and PSA expression, suggesting a role in activity-dependent structural remodeling.
• PSA-NCAM is implicated in processes underlying learning and regeneration in the vertebrate nervous system.