Réntǐ dànǎo zhōng yuē yǒu 860 yì gè shénjīng xìbāo.
The human brain has approximately 86 billion nerve cells.
Shénjīng xìbāo sǔnshāng hòu hěn nán zàishēng.
Nerve cells are difficult to regenerate after damage.
Kēxuéjiā zhèngzài yánjiū rúhé bǎohùshén jīng xìbāo.
Scientists are studying how to protect nerve cells.
