The bile steroid chenodeoxycholate is a potent antagonist at NMDA and GABAA receptors

► Bile steroids are produced in the liver and in the brain. ► Bile steroids (BS) serve digestion of lipids in the gut and modulate neuronal activity in the brain. ► BS are NMDA and GABAA receptor antagonists modulating neuron firing. ► Chenodeoxycholate is most potent and when missing may lead to the neuronal dysfunction.