Carbon monoxide (CO), produced in the body by the enzyme heme oxygenase (HO), has been suggested as a retrograde synaptic messenger with a prominent role in the long-term potentiation (LTP) of certain areas of the brain. LTP of sympathetic ganglia is 5-HT(3) receptor-dependent and has been shown to require nitric oxide for the maintenance, but not for the induction, phase. We investigated the p...
