# Hippocampal Metabolomics Reveal the Mechanism of α-Conotoxin [S9K]TxID Attenuating Nicotine Addiction

## TL;DR

This study explores how a compound called [S9K]TxID reduces nicotine addiction by altering brain metabolism, particularly affecting amino acid pathways.

## Contribution

The study identifies specific metabolic changes caused by [S9K]TxID in nicotine addiction, highlighting its potential as a therapeutic compound.

## Key findings

- [S9K]TxID reduces nicotine-induced conditioned place preference without CNS inhibition.
- Eight metabolites, including phenylalanine, are significantly altered by [S9K]TxID treatment.
- The compound regulates biosynthesis of phenylalanine, tyrosine, and tryptophan to counter nicotine effects.

## Abstract

Nicotine is the main substance responsible for the development of tobacco addiction. The α3β4 nicotinic acetylcholine receptors (nAChRs) are a potential key target for mitigating nicotine reward. Preliminary studies in our laboratory suggest that α-conotoxin [S9K]TxID serves as a selective and potent antagonist targeting α3β4 nAChRs, which may be beneficial in addressing nicotine addiction. However, the mechanisms of [S9K]TxID treatment in nicotine addiction are still to be determined. This study aimed to identify the differential metabolic profiles of [S9K]TxID treatment in nicotine addiction using an untargeted metabolomic profiling method. As demonstrated by behavioral experiments, [S9K]TxID effectively attenuated nicotine-induced conditioned place preference (CPP) expression without exerting inhibitory effects on the central nervous system (CNS). The results of untargeted metabolomics revealed that eight metabolites were significantly altered after [S9K]TxID treatment, particularly phenylalanine. [S9K]TxID also attenuated nicotine-induced metabolic disorders by regulating phenylalanine, tyrosine and tryptophan biosynthesis. In conclusion, our findings suggest that [S9K]TxID could be a potential therapeutic compound for nicotine addiction.