5,7-Dihydroxytryptamine

5,7-Dihydroxytryptamine Full Name

5,7-Dihydroxytryptamine (conjugated)

5,7-Dihydroxytryptamine Introduction

5,7-Dihydroxytryptamine (5,7-DHT) is a synthetic neurotoxin structurally related to the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). It is a highly selective and invaluable research tool used to create experimental models of specific serotonergic neurodegeneration. By allowing scientists to chemically lesion serotonin-producing neurons in the brain, 5,7-DHT has been fundamental in elucidating the diverse functions of the serotonergic system in behavior, mood, cognition, and neurological disorders.

Figure 1. Strcuture of 5,7-Dihydroxytryptamine.

Chemical Properties and Mechanism of Action
5,7-DHT is a dihydroxylated indolealkylamine. Its selective neurotoxicity arises from its structural similarity to serotonin, which enables its active uptake into serotonergic neurons via the presynaptic serotonin transporter (SERT). Once inside the neuron, 5,7-DHT undergoes auto-oxidation, generating reactive oxygen species and quinones. These cytotoxic products induce severe oxidative stress, leading to the irreversible damage and eventual degeneration of the nerve terminal and, in higher doses, the cell body. To maximize its selectivity for serotonin neurons over catecholamine (e.g., dopamine, norepinephrine) neurons, researchers typically pre-treat animals with a norepinephrine transporter (NET) inhibitor, such as desipramine, prior to 5,7-DHT administration.

Conclusion and Significance
Despite the advent of modern genetic and viral tools, 5,7-DHT remains a classic and powerful method for establishing causal links between serotonergic integrity and brain function. The models generated with this neurotoxin have been instrumental in validating the "serotonin hypothesis" of affective disorders and in understanding the broad neuromodulatory influence of serotonin. Research using 5,7-DHT continues to inform the development of pharmacological treatments targeting the serotonergic system for conditions ranging from major depression to migraine and obsessive-compulsive disorder.

Alternate Names for 5,7-Dihydroxytryptamine

5 7 DHT; 5 7 Dihydroxytryptamine; 5,7-Dihydroxytryptamine