Complex sentence: Greenough is regarded as the predominant researcher to have demonstrated that the brain continues to form new synaptic connections between nerve cells throughout life, responding to environmental enrichment and learning, and that this mechanism is fundamental to learning and memory storage in the brain.
Split into simpler sentences: Greenough is regarded as the predominant researcher to have demonstrated that the brain continues to form new synaptic connections between nerve cells throughout life in response to environmental enrichment and learning. This mechanism is fundamental to learning and memory storage in the brain.