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24th European Congress of Psychiatry / European Psychiatry 33S (2016) S116–S348

S235

Disclosure of interest

The authors have not supplied their decla-

ration of competing interest.

http://dx.doi.org/10.1016/j.eurpsy.2016.01.465

EW348

Gamma band dysfunction in patients

with schizophrenia during a

Sternberg Task: A wavelet analysis

D.D. Marasco

1 ,

, G .

Di Lorenzo

2 , A.

Petito

1 , M.

Altamura

1 ,

G. Francavilla

1

, L. Inverso

1

, A. Bellomo

1

1

Laboratory of Neurophysiology, Department of Clinical and

Experimental Medicine, Section of Psychiatry, University of Foggia,

Foggia, Italy

2

Laboratory of Psychophysiology, Department of Systems Medicine,

University of Rome “Tor Vergata”, Rome, Italy

Corresponding author.

Background

Increasing body of evidence suggest that patients

with schizophrenia (SCZ) present dysfunction of the gamma band

oscillations (GBO) during cognitive tasks. The current study aimed

to explore the GBO activity in SCZ during a Sternberg task.

Materials and methods

Twenty-eight chronic stabilized SCZ and

18 healthy controls (HC), were recruited. Ongoing EEG was

recorded during the execution of the Sternberg task. Continu-

ous EEG data were band-pass filtered (1–100Hz) and corrected

for eye blink and muscle artefacts by ICA. For each subject,

the event-related-spectral-perturbation (ERSP) and the inter-trial-

coherence (ITC) were computed at the Pz channel only for

those stimulus-locked segments containing correct responses. GBO

wavelet analysis was performedwith two different increasing cycle

ranges (3 to 5.8 and 12 to 22.6; frequency range: 30–90Hz), to

obtain the best information about temporal and frequency dynam-

ics. Student’s t test (withmultiple comparisons FDR correction) was

used to compare the groups.

Results

During the manteinance phase (4000 to 4600ms after

the stimulus onset), SCZ presented a significant increase, respect

to HC, in low GBO activity (range: 30-50Hz;). In the other phases

of the Sternberg task (encoding, probe presentation and response

periods), no significant difference in GBO was observed between

SCZ and HC.

Conclusions

These findings are in line with the evidence that GBO

dysfunction in SCZ is present during selective phases of the work-

ing memory task. Future studies have to clarify the role of GBO

dysfunction on the cognitive performance and the clinical utility of

selective GBO modulation during cognitive rehabilitation.

Disclosure of interest

The authors have not supplied their decla-

ration of competing interest.

http://dx.doi.org/10.1016/j.eurpsy.2016.01.466

EW349

Sweet and bitter taste perception in

anorexia nervosa: A functional MRI

study

A.M. Monteleone

1 ,

, F . E

sposito

2 , A. P

rinster

3 , E. C

antone

4 ,

A. Canna

3 , F. P

ellegrino

1 , M.

Nigro

1 , R. A

modio

1 , U.

Volpe

1 ,

F. Di Salle

2 , P. M

onteleon

e 2

1

Second University of Naples, Department of Psychiatry, Naples, Italy

2

University of Salerno, Neuroscience Section, Department of

Medicine and Surgery, Salerno, Italy

3

National Research Council, Biostructure and Bioimaging Institute,

Naples, Italy

4

Federico II University, ENT Department, Naples, Italy

Corresponding author.

Introduction

Taste perception is a complex phenomenon mod-

ulated by different factors, such as taste receptors and memory

brain circuits. The palatability of the food, that activates the central

reward pathways, also plays an important role in taste perception.

It means that taste is able to influence the choice of food and then

eating behaviour.

Objectives

It is well known that people with anorexia nervosa

(AN) have a lower sensitivity to reward stimuli and recent stud-

ies suggested that altered function of taste neural circuitry may

contribute to restricted eating in AN.

Aims

The aim of this study was to evaluate, in patients suffering

from AN, the activation of brain areas involved in taste perception

and in central reward mechanisms to both pleasant and aversive

taste stimuli and to correlate gustatory neurocircuitry activity with

eating behaviours, temperament measures and/or sensitivity to

reward and to punishment.

Methods

Fifteen underweight female AN patients and sixteen

normal-weight healthy women underwent a functional MRI to

measure brain areas activation to repeated stimuli of a pleasant

taste (sucrose solution), alternated with an aversive taste (bitter

solution), and water taste.

Results

Compared to healthy controls, patients with AN showed

a significantly reduced activation of left insula and left dorsolateral

prefrontal cortex to sweet stimulus and reduced activation of right

parietal cortex to bitter stimulus.

Conclusions

These results, if confirmed in future studies, may

improve our knowledge about the pathophysiological mechanisms

of AN.

Disclosure of interest

The authors have not supplied their decla-

ration of competing interest.

http://dx.doi.org/10.1016/j.eurpsy.2016.01.467

EW350

Implication of altered 7 nicotinic

receptors and amyloid deposition in

the Alzheimer’s brain

K. Nakaizumi

1 ,

, T . T

erada

2 , E. Y

oshikawa

3 , A.

Kakimoto

3 ,

I. Takashi

3 , I. S

uzuk

i 3 , B. T

omoyasu

2 , K. S

uzuki

1 , Y. M

agata

4 ,

N. Mori

1 , Y. O

uchi

2

1

Hamamatsu University School of Medicine, Psychiatry, Hamamatsu,

Japan

2

Hamamatsu University School of Medicine, Biofunctional Imaging,

Hamamatsu, Japan

3

Hamamatsu Photonics K.K.- Hamamatsu- Japan, Central Research

Laboratory, Hamamatsu, Japan

4

Hamamatsu University School of Medicine, Molecular Imaging-

Medical Photonics Research Center, Hamamatsu, Japan

Corresponding author.

Introduction

Brain amyloid- protein (A ) deposition is a key

pathology of Alzheimer’s disease (AD). Cholinergic degeneration,

including reductions in 7 nicotinic acetylcholine receptors ( 7-

nAChR), is also known as a pathophysiology of AD. Recent imaging

studies have shown cognitively normal subjects with A depo-

sitions, indicating a missing link between A deposition and

cognitive decline.

Objectives

To clarify relationships among the A burden, 7-

nAChR availability, and cognitive declines in AD.

Aims

To measure brain A deposition and 7-nAChR availability

in the same patients with AD using positron emission tomography

(PET).

Methods

Twenty AD patients and age-matched 20 healthy adults

were studied. The 7-nAChR availability and A deposition were

evaluated using PET with [

11

C]MeQAA and [

11

C]PIB, respectively.

Levels of specific binding were estimated by a simplified reference

tissue method (BP

ND

) for [

11

C]MeQAA and a tissue ratio method

(SUVR) for using [

11

C]PIB. The values were compared with clinical

measures of various cognitive functions using regions of interest

(ROIs)-based and statistical parametric mapping (SPM) analyses.

Results

[

11

C]MeQAA BP

ND

levels were extensively lower in the

cholinergic projection regions of AD. There was a significant