Wide impairment of cerebral serotoninergic activity but inter-individual heterogeneity in bulimia nervosa patients: a pilot [¹⁸F]MPPF/PET study

Abstract

Objectives. Bulimia nervosa (BN) is associated with abnormalities of serotoninergic system. Functional or ligand specific brain imaging studies revealed abnormalities in non-overlapping regions. [¹⁸F]MPPF (4-(2-methoxyphenyl)-1-[2-(N-2-pyridinyl)-p-fluorobenzamido]-ethylpiperazine) is a selective 5-HT_1A receptor antagonist with a serotonin-like affinity, capable to assess changes of brain serotoninergic activity in BN patients. Methods. [¹⁸F]MPPF cerebral binding potential (BP_ND) was measured by positron emission tomography scan in nine purging-type BN patients and eleven age-matched controls. Voxel-based statistical parametric mapping (SPM) analyses were performed to assess BP_ND differences between the two groups and between each BN patient and controls group. Results. Mean [¹⁸F]MPPF BP_ND was overall increased in BN patients. SPM analysis with revealed symmetrical large clusters of increased [¹⁸F]MPPF binding in insula, temporo-parietal cortex, prefrontal cortex, in limbic, paralimbic cortex and raphe nuclei. SPM individual analysis indicated significant heterogeneity of [¹⁸F]MPPF mapping within BN group, including cases with isolated up to widespread increased binding. [¹⁸F]MPPF BP_ND did not covariate with depression or eating behaviour-related scores. Conclusions. Large clusters of increased [¹⁸F]MPPF binding in severe BN overlap previous results, separately described within fMRI or PET studies. The relationship between the inter-individual [¹⁸F]MPPF binding heterogeneity and serotoninergic modulators efficacy in these patients remains to be assessed.

Key words::

• brain imaging
• eating disorders
• serotonin receptor
• PET
• depression

Acknowledgements

This work was supported by grant no. A01041KS from ATC (Action Thématique Concertée) Nutrition, France.

Statement of interest

None to declare.