Basic fibroblast growth factor and epidermal growth factor exert differential trophic effects on CNS neurons

Area of Science:

• Neuroscience
• Cell Biology
• Developmental Biology

Background:

• Epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) are known mitogens.
• Both factors can promote survival and neurite outgrowth in central nervous system neurons.
• The specific neuronal subtypes responsive to these growth factors are not fully understood.

Purpose of the Study:

• To investigate the differential effects of EGF and bFGF on cerebellar neurons and astrocytes.
• To determine the dose-dependency of EGF's effects on neuronal survival and process outgrowth.

Main Methods:

• Primary cultures of neonatal rat cerebellar neurons and astrocytes were used.
• Cells were treated with varying concentrations of EGF and bFGF.
• Neuronal survival, process outgrowth, and astrocyte proliferation ([3H]thymidine incorporation) were measured.

Main Results:

• EGF significantly enhanced survival and process outgrowth of cerebellar neurons in a dose-dependent manner, effective at concentrations as low as 100 pg/ml.
• bFGF did not enhance survival or neurite elongation in cerebellar neurons within the tested concentration range (0.1–10.0 ng/ml).
• bFGF stimulated [3H]thymidine incorporation in cerebellar astrocytes, indicating its mitogenic activity on glial cells.

Conclusions:

• EGF acts as a potent survival and neurite outgrowth factor for cerebellar neurons.
• EGF demonstrates trophic activity across various central nervous system regions, including striatal, cortical, and cerebellar neurons.
• bFGF appears to influence more restricted neuronal populations and glial cells within the cerebellum.