BACKGROUND: Central serotonin (5HT) plays a major role in emotional processing. We used functional neuroimaging (fMRI) to investigate the effects of experimental manipulation of central 5HT levels on the regional neural response to happy and sad facial expressions. METHODS: Ten healthy participants (eight men and two women) were scanned during an implicit emotional processing task after receiving a tryptophan-free (acute tryptophan depletion, ATD) or a balanced amino acid drink in a double-blind design. RESULTS: ATD lowered total plasma tryptophan concentration by 80%. There was no significant effect on subjective mood ratings, on response accuracy and on reaction times. Compared to sham depletion, ATD attenuated activation in the right medial/inferior frontal gyrus, the posterior cingulate cortex, the occipital and parietal cortex bilaterally, the right hippocampus, claustrum and insula. Conversely, ATD was associated with relatively increased activation in the left inferior frontal gyrus. ATD had differential effects on activation during the processing of happy and sad faces in the right putamen and in the left superior temporal gyrus. CONCLUSIONS: In both cortical and sub-cortical regions, the neural response associated with processing emotional faces is significantly modulated by 5HT manipulation resulting from ATD. Moreover, in certain areas, this effect of 5HT depends on the emotional valence of the stimulus.
BACKGROUND: Central serotonin (5HT) plays a major role in emotional processing. We used functional neuroimaging (fMRI) to investigate the effects of experimental manipulation of central 5HT levels on the regional neural response to happy and sad facial expressions. METHODS: Ten healthy participants (eight men and two women) were scanned during an implicit emotional processing task after receiving a tryptophan-free (acute tryptophan depletion, ATD) or a balanced amino acid drink in a double-blind design. RESULTS: ATD lowered total plasma tryptophan concentration by 80%. There was no significant effect on subjective mood ratings, on response accuracy and on reaction times. Compared to sham depletion, ATD attenuated activation in the right medial/inferior frontal gyrus, the posterior cingulate cortex, the occipital and parietal cortex bilaterally, the right hippocampus, claustrum and insula. Conversely, ATD was associated with relatively increased activation in the left inferior frontal gyrus. ATD had differential effects on activation during the processing of happy and sad faces in the right putamen and in the left superior temporal gyrus. CONCLUSIONS: In both cortical and sub-cortical regions, the neural response associated with processing emotional faces is significantly modulated by 5HT manipulation resulting from ATD. Moreover, in certain areas, this effect of 5HT depends on the emotional valence of the stimulus.
Authors: M L Phillips; A W Young; S K Scott; A J Calder; C Andrew; V Giampietro; S C Williams; E T Bullmore; M Brammer; J A Gray Journal: Proc Biol Sci Date: 1998-10-07 Impact factor: 5.349
Authors: Simon Surguladze; Michael J Brammer; Paul Keedwell; Vincent Giampietro; Andrew W Young; Michael J Travis; Steven C R Williams; Mary L Phillips Journal: Biol Psychiatry Date: 2005-02-01 Impact factor: 13.382
Authors: Eileen Daly; Quinton Deeley; Brian Hallahan; Michael Craig; Michael Brammer; Melissa Lamar; Anthony Cleare; Vincent Giampietro; Christine Ecker; Lisa Page; Fiona Toal; Mary L Phillips; Simon Surguladze; Declan G M Murphy Journal: Psychopharmacology (Berl) Date: 2010-04-28 Impact factor: 4.530
Authors: Ronald M Salomon; Ronald L Cowan; Baxter P Rogers; Mary S Dietrich; Amy Lynn Bauernfeind; Robert M Kessler; John C Gore Journal: Psychiatry Res Date: 2011-01-13 Impact factor: 3.222
Authors: Oliver J Robinson; Cassie Overstreet; Philip S Allen; Alison Letkiewicz; Katherine Vytal; Daniel S Pine; Christian Grillon Journal: Neuroimage Date: 2013-04-11 Impact factor: 6.556
Authors: Paolo Fusar-Poli; Anna Placentino; Francesco Carletti; Paola Landi; Paul Allen; Simon Surguladze; Francesco Benedetti; Marta Abbamonte; Roberto Gasparotti; Francesco Barale; Jorge Perez; Philip McGuire; Pierluigi Politi Journal: J Psychiatry Neurosci Date: 2009-11 Impact factor: 6.186