Long-term potentiation in autonomic ganglia: Potential role in cardiovascular disorders

Table 2 Effects of various 5-HT₃ receptor agonists and antagonists on compound action potential during ganglionic long-term potentiation induced in vitro by high frequency repetitive stimulation

Serotonergic drugs	Mode of action	Compound AP
Serotonin (10-20 μmol/L)	Agonist	Increased
Fluoxetine (10 μmol/L)	SSRI	Increased
m-CPBG (1 μmol/L)	Receptor agonist	Increased
Tropisetron (5 μmol/L)	Receptor antagonist	Reduced
Ondansetron (5 μmol/L)	Receptor antagonist	Reduced
MDL 72222 (0.5 μmol/L)	Receptor antagonist	Reduced
Reserpine pretreatment (3 mg/kg)	5-HT3 depletion	No gLTP
m-CPBG (1 μmol/L) + reserpine	Receptor agonist	Increased

The same drugs produced no significant effect on basal synaptic transmission in control ganglia (adapted from ref. [15,25,29,30,32,33,36]). SSRI: Selective serotonin reuptake inhibitor; AP: Action potential.