2009 Abstracts - Association for Chemoreception Sciences

comprehensive assessment of olfactory function we used the“Sniffin´ Sticks” odor threshold and odor identification test.Furthermore we analyzed chemosensory event related potentialsin response to pleasant and unpleasant olfactory stimuli andtrigeminal activation. Additionally participants answered aquestionnaire for current symptoms of posttraumatic stressdisorder (PTSD). Results: Contrary to our hypothesis we foundno significant difference between the cm-group compared to thetwo control groups. However, there was a significant correlationbetween current symptoms of PTSD and olfactory function.Following statistical adjustment for depressive symptoms asignificant correlation remained between PTSD symptoms andodor identification, N1 latencies in response to the unpleasanttrigeminal (CO 2 ) and olfactory (H 2 S) stimuli, and N1 amplitudesin response to the same unpleasant stimuli. Conclusions: Theresults indicate a preferred processing of unpleasant stimuli inpatients with PTSD - irrespective of the childhood history - andfit the information dissociation theory in PTSD. Because we didnot find changes in olfactory function depending on cm, theinfluence of current psychopathology appears to be of highersignificance to the amygdalae and orbitofrontal function than thechildhood history.#P5 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuits“Anosmic smell”: Residual olfactory function followinghemispherectomyJelena Djordjevic, Faye Pesenti, Alain PtitoMontreal Neurological Institute, McGill University Montreal,QC, CanadaHemispherectomy is a relatively rare neurosurgical procedure,done to treat intractable epileptic seizures, involving completeremoval or deafferentation of a whole cerebral hemisphere.We examined olfactory function in one subject who underwenthemispherectomy, and compared her performance to that of ahealthy control volunteer, matched for age and gender. DR is a31-year-old right-handed woman whose level of intellectualfunction is in the average range. At age 5, at onset of epilepticseizures, she was diagnosed with Rasmussen’s chronicencephalitis. At age 17, she underwent a right functionalhemispherectomy. We tested olfactory function separately ineach nostril, examining her detection thresholds, qualitydiscrimination, and identification, with Sniffin’ Sticks. In addition,we requested a confidence rating after each response, in order tocompare confidence levels associated with correct versus incorrectresponses. As expected, her olfactory performance was preservedwith the nostril contralateral to the removed hemisphere. Incontrast, she was considerably impaired when tested ipsilaterally.Notably, while her threshold and discrimination results were atchance, she was still able to identify stimuli, albeit with difficulty.Furthermore, she showed a normal divergence of confidencewithin each task : higher confidence was associated with correctresponses and lower confidence with incorrect ones, and this wasthe case both when tested ipsi- and contralaterally to the lesion.These results demonstrate residual rudimentary olfactory functionipsilaterally to the removed hemisphere, which we call “anosmicsmell” and they parallel the “blindsight” abilities previouslydocumented in this subject. Results are discussed in light of herpostoperative MRI findings.#P6 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsThe perception of malodors: An fMRI study of age and genderrelated differences between pre and post puberty subjectsThomas Hummel 1 , Arianne Baur 1 , Cornelia Hummel 1 ,Anita Chopra 21Smell & Taste Clinic, University of Dresden Medical SchoolDresden, Germany, 2 Unilever Research and Development PortSunlight Wirral, United KingdomAlthough learning, experience and socialisation strongly influencethe individual perception of odors, central nervous processing ofodorous stimuli in different stages of adolescence has to date onlyrarely been studied. In spite of frequent reports about age andgender modulating odor perception, fMRI has scarcely beenapplied to substantiate these differences. In this study, 20 righthanded subjects were grouped according to gender and age (prepuberty: 9 - 12 yrs. and post puberty: 17 20 yrs.) to build fourequally sized samples. By means of fMRI, patterns of cerebralactivation in pre and post puberty girls and boys after nasalstimulation with three malodors were compared(Androstadienone, 2-Methyl-3-Mercaptobutanol and H 2 S).Data analysis did not reveal significant gender differences, butactivation patterns were found to differ between age groups.While pre puberty subjects mainly showed activation of earlierprojection stages of odor processing, namely piriform cortex andamygdala, in post puberty participants, enhanced activation wasrevealed in neocortical areas (insula and medial and inferiorfrontal gyri). This finding may be interpreted in terms ofintegrative aspects of odor processing playing an important role inthe post puberty group. The pattern of enhanced neocorticalactivation could reflect a more advanced stage of social andcognitive development.#P7 Poster session I: Chemosensory disorders,models and aging/Central chemosensory circuitsOdor judgments in first episode and chronicschizophrenia patientsClaudia I. Rupp 1 , Georg Kemmler 1 , Thomas Walch 1 ,Arne W. Scholz 2 , Martina Klimbacher 1 , Theresia Lechner 1 ,Hartmann Hinterhuber 1 , Wolfgang W. Fleischhacker 11Innsbruck Medical University, Department of Psychiatry andPsychotherapy Innsbruck, Austria, 2 Innsbruck Medical University,Department of Otorhinolaryngology Innsbruck, AustriaThere is consistent evidence that schizophrenia patients haveolfactory dysfunction. Impairments in olfactory identification,quality discrimination as well as sensitivity are well described.There has been little investigation of olfactory judgments inschizophrenia, and the few findings are controversial. The aim ofthis study was to determine whether patients experiencing a firstepisodeschizophrenia and patients with chronic schizophreniadiffer in odor judgments. Olfactory judgment measures includedintensity, edibility, familiarity and hedonic ratings. Subjects wereasked to rate edibility, familiarity and hedonic about 16 everydayodors (real-world items) on visual 7-point rating scales. Half ofodors were edible, half not. Olfactory intensity judgments wereperformed using the odors from an identification task (Sniffin’Sticks). Unirhinal performance in olfactory judgments werecompared between young first-episode patients, young patientswith chronic schizophrenia and healthy controls similar in age28 | AChemS Abstracts 2009