Figure 1From: Vitamin B6 reduces hippocampal apoptosis in experimental pneumococcal meningitis Schematic of the kynurenine pathway in the rat brain. Tryptophan is metabolized over multiple steps into quinolinic acid, finally resulting in de novo synthesis of NAD+. Several neuroactive intermediates are included in this pathway: neuroprotective kynurenic acid, neurotoxic 3-hydroxykynurenine and neurotoxic 3-hydroxyanthranilic acid. Neurotoxic intermediates are written in red, neuroprotective ones in green [6, 7].Back to article page