Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SMELL”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,495 records · Page 83Linked to original sources
PubMed1993

Olfactory memory in unmedicated schizophrenics.

Previous studies have indicated that schizophrenic patients have olfactory deficits. The question as to whether olfactory deficits are due to chronic effects of medication has not been addressed. This is the first paper to report that never-medicated schizophrenic patients also have olfactory deficits. Twenty four normal subjects and twenty unmedicated schizophrenic patients were examined with two tests of olfactory function: the University of Pennsylvania Smell Identification Test (UPSIT) and a match-to-sample olfactory memory test. Results indicated that schizophrenics did poorly on both the UPSIT and the olfactory match-to-sample memory test relative to sex and age-matched controls. ANCOVA showed that the deficit in performance on the olfactory match-to-sample test was still present even when the variance due to the UPSIT was taken out of the analysis. Deficits in olfactory identification and olfactory memory are consistent with the concept that schizophrenics have dysfunctional limbic systems.

Blood Glucose↗
PubMed1995

Olfactory deficits in schizophrenia are not a function of task complexity.

The purpose of the current study was to determine if olfactory identification deficits in patients with schizophrenia were related to task complexity. Given that we had previously reported that male patients with schizophrenia are the most impaired on olfactory identification tests (the University of Pennsylvania Smell Identification Test, UPSIT), we wished to determine whether a similar deficit would exist for this group on a task of similar format and complexity, the Colour Identification Test (CIT). Sixty-five neuroleptically medicated patients with a DSM-III-R diagnosis of schizophrenia and 30 normal control subjects participated. The dependent measures were scores on the UPSIT and CIT. Overall, patients with schizophrenia had significantly lower USPIT scores than did the normal control subjects whereas no mean difference was observed for colour identification. Male patients with schizophrenia had olfactory identification deficits but performed comparably to all other groups on the CIT. Furthermore, microsmic patients with schizophrenia had CIT scores that did not differ from normal control subjects. Finally, CIT and UPSIT scores were not significantly correlated for the study sample as a whole. The results of this study suggest that the olfactory identification deficits observed in patients with schizophrenia likely reflect abnormalities of brain areas involved in olfactory pathways and are not a function of task complexity.

Adolescent↗
PubMed1994

Olfactory hallucinations and olfactory identification ability in patients with schizophrenia and other psychiatric disorders.

Olfactory identification ability and the prevalence of olfactory hallucinations were examined in 183 hospitalized patients from three diagnostic groups. One hundred and thirty-one patients with schizophrenia, 21 patients with major depression, 31 women with eating disorders along with 77 normal control subjects were examined using the University of Pennsylvania Smell Identification Test (UPSIT) and were questioned regarding the presence of olfactory hallucinations. Olfactory identification deficits were observed only in patients with schizophrenia. In contrast, olfactory hallucinations were reported by members of all psychiatric diagnostic categories (34.6% of patients with schizophrenia; 19% of depressed patients and 29% of eating disorders patients). For patients with schizophrenia, women were more likely to report olfactory hallucinations and had higher UPSIT scores than men.

Adolescent↗
PubMed1994

Further evidence for olfactory identification deficits in schizophrenia.

Forty-seven schizophrenic patients and 36 normal controls, matched for smoking history, were administered the University of Pennsylvania Smell Identification Test (UPSIT) and the Picture Identification Test (PIT). Amongst subjects successfully completing the PIT, non-smoking schizophrenic patients had significantly lower UPSIT scores than non-smoking controls. Smoking history and diagnosis did not interact to produce any pronounced effect. No significant gender difference was found. These results suggest schizophrenics display decreased olfactory identification even if likely confounders are adequately controlled.

Adolescent↗
PubMed2006

Can odours acquire fat-like properties?

Odours can acquire taste-like properties via simultaneous pairing in the mouth with tastants like sucrose. The experiment reported here sought to test whether qualities other than taste may also be acquired. Participants received pairings between odour A and low-fat unsweetened milk (LFUN), odour B and low-fat sweetened milk (LFSW), odour C and high-fat unsweetened milk (HFUN) and odour D and high-fat sweetened milk (HFSW). On test, participants reported that odours paired with milks perceived as being fattier (i.e. LFSW, HFUN, HFSW) were judged to smell fattier than they did prior to conditioning. In a further test, participants were asked to sample each of the four odours in a slightly fatty-sweet milk target. Odours previously paired with high-fat milks enhanced perceived fattiness of the target, whilst odours previously paired with sweetened milks enhanced perceived sweetness. These results were not well accounted for by participants' explicit knowledge of the odour-milk pairings and suggest that fat-like qualities may be acquired.

Adolescent↗
PubMed2006

The clinical significance of electrophysiological measures of olfactory function.

AIM: To establish the detectability of olfactory event-related potentials (OERP) in relation to the results from psychophysical tests of olfactory function. METHODS: Fifty-nine men and 64 women (aged 19-89 years) participated all of whom presented themselves to a specialized "Smell and Taste Clinic" because of chemosensory complaints. Their olfactory function was assessed by means of psychophysical tests, e.g., assessment of odor threshold, odor discrimination, and odor identification, which were combined in a composite "Threshold Discrimination Identification" score ("TDI score"). OERP were obtained in response to the olfactory stimulant phenyl ethyl alcohol; their presence/absence was judged by a trained observer. Using logistic regression the TDI score was calculated in relation to the subjects' olfactory function at which the probability of the presence of OERP became greater than chance. RESULTS: Based on psychophysical tests, 40 subjects were diagnosed with functional anosmia, 40 with hyposmia, and 43 subjects scored within the normal range. Causes of hyposmia and anosmia included congenital anosmia, Parkinson's disease, head trauma, infections of the upper respiratory tract, and sinunasal disease. A TDI score of 22.6 equivalent to "pronounced hyposmia" was identified as the turning point at which the probability of detection of OERP was higher than 50%. Its 95% confidence interval of 16.1-27.8 well reflected the range of hyposmia, i.e., was above significant loss of olfactory function (functional anosmia, TDI score<15.5) and below normal olfactory function (TDI score>30.5). CONCLUSION: The present results indicate that the probability to detect an OERP becomes greater than 50% within a range of olfactory function that separates functional anosmia from normosmia. Presence of OERP clearly signifies presence of olfactory function while this is not always the other way around with absence of OERP.

Adult↗
PubMed2005

Odor mixture alters neural resources during symbolic problem solving.

The smell of a cup of coffee is produced by many different odor chemicals combined in a mixture, yet the perception of that odor is of a single unified whole. Recent evidence has demonstrated that mixtures of odors share some of the same spatiotemporal features of speech sounds and may use similar brain resources in associating those features with the symbols they represent. This experiment investigated the hypothesis that an odor mixture would interfere with a math task that requires symbolic but not spatial processing. Results indicated the pattern of brain electrical activity was similar for the single odors and the mixture during spatial processing. During solution of the task requiring symbolic processing, the odor mixture produced a pattern of brain electrical activity different from the single odorants. These data suggest that the perception of odor mixtures may use some of the same resources associated with symbolic processing.

Adolescent↗
PubMed2005

Gustatory stimulation influences the processing of intranasal stimuli.

OBJECTIVES: Taste and smell interact. The aim of this study was to examine this interaction using gustatory and olfactory stimuli applied at the same time, which exhibited perceptual compatibility and incompatibility. METHODS: Thirty-two, young, healthy normosmic subjects (16 men, 16 women) took part in two randomized sessions. Event-related potentials (ERP) were recorded in response to vanillin, or gaseous CO2. These two conditions were combined with three "taste conditions" including sweet taste, sour taste, and the intraoral presentation of an empty taste dispenser. RESULTS: Vanillin responses were largest for the "sweet" condition, while they were smaller for the "sour condition". In contrast, responses to CO2 were largest under the "sour" condition, and smallest under the "sweet" condition. Moreover, during the "sweet" condition the latencies of P1 and N1 were shorter than in the "sour" condition, which was the other way around for CO2. CONCLUSIONS: Results of the present investigation suggested that (1) the early processing of intranasal chemosensory stimuli is modulated through concomitant gustatory stimulation, and that (2) this modulation may depend, at least in part, on the contextual compatibility between intranasal and intraoral stimuli.

Adult↗
PubMed2004

[Experimental study on the sensory capabilities of coral-reef fish larvae for the recognition of their settlement location].

Some experiments in aquarium and in situ have been carried out to investigate the sensory abilities of coral reef fish larvae in the recognition of their settlement location. Ten out 12 species studied detected their settlement location due to the presence of conspecifics and not by habitat characteristics. Larvae use three senses in this detection: sight, smell and vibratory sense.

Animal Migration↗
PubMed2006

[Olfactory receptors and odour coding].

The first step of olfactory detection involves interactions between odorant molecules and neuronal protein receptors. Odour coding results from the combinatory activation of a set of receptors and rests on their clonal expression and olfactory neurone connexion, which lead to formation of a specific sensory map in the cortex. This system, sufficient to discriminate myriads of odorants with a mere 350 different receptors, allows humans to smell molecules that are not natural (new cooking flavours, synthetic chemicals...). The extreme olfactory genome diversity explains the absence of odour semantics. Olfactory receptors are also involved in cellular chemotaxis.

Animals↗
PubMed2005

Dynamic instability at liquid/vapor interface far from equilibrium.

Attempt has been made to elucidate the mechanism of electric potential oscillations at oil-aqueous solution interface involving adsorption at oil-vapor interface on a semi-theoretical basis. The mechanism stipulates adsorption of ammonia, amines and pheromones at the liquid-vapor interface followed by transfer of ions through membrane-aqueous solution interface and subsequent interaction of ammonium (amine) ions and carbocations from pheromones with diffusing halide ions from the bulk. Relationship of the above mechanism with sensing mechanism of smell by olfactory nerves has also been pointed out.

Adsorption↗
PubMed2007

Sildenafil affects olfactory function.

PURPOSE: Sildenafil is the first member of a new class of oral drugs effective for erectile dysfunction. However, approximately 20% of patients complain about nasal congestion after sildenafil administration. MATERIALS AND METHODS: Because nasal airflow and olfaction are closely linked, the sense of smell was evaluated in 20 young, healthy volunteers after the administration of 50 and 100 mg sildenafil, and placebo in a double-blinded, crossover study. Olfactory function was evaluated using a standardized and validated test (Sniffin' Sticks). To investigate a possible impact of G-protein beta3 subunit C825T polymorphism on the effect of sildenafil on olfaction the genotype of all subjects was determined. RESULTS: The effect of sildenafil on olfaction was only present at a dose of 100 mg but not at a dose of 50 mg sildenafil. The genotypes TT, CC and TC of the G-protein beta3 C825T polymorphism had no impact on the change in olfactory function. CONCLUSIONS: Higher sildenafil doses may produce decreased olfactory sensitivity.

Cross-Over Studies↗
PubMed2006

Disrupted compartmental organization of axons and dendrites within olfactory glomeruli of mice deficient in the olfactory cell adhesion molecule, OCAM.

There is an overall topographic connectivity in the axonal projections of olfactory sensory neurons from the olfactory epithelium (OE) to the olfactory bulb (OB). The molecular determinants of this overall topographic OE-OB connectivity are not known. For 20 years, the intriguing expression pattern of the olfactory cell adhesion molecule (OCAM) has made it the leading candidate as determinant of overall topographic OE-OB connectivity. Here, we have generated a strain of OCAM knockout mice by gene targeting. There were no obvious alterations in the distribution of olfactory sensory neurons within the OE or in the coalescence of axons into specific glomeruli. However, the compartmental organization of dendrites and axons within the glomeruli was disrupted. Surprisingly, the mutant mice exhibited an increase in olfactory acuity; they appeared to have a better sense of smell. Thus, despite its striking expression pattern, OCAM is not essential for overall topographic OE-OB connectivity. Instead, OCAM is required for establishing or maintaining the compartmental organization and the segregation of axodendritic and dendrodendritic synapses within glomeruli.

Animals↗
PubMed2006

Reading cinnamon activates olfactory brain regions.

Some words immediately and automatically remind us of odours, smells and scents, whereas other language items do not evoke such associations. This study investigated, for the first time, the abstract linking of linguistic and odour information using modern neuroimaging techniques (functional MRI). Subjects passively read odour-related words ('garlic', 'cinnamon', 'jasmine') and neutral language items. The odour-related terms elicited activation in the primary olfactory cortex, which include the piriform cortex and the amygdala. Our results suggest the activation of widely distributed cortical cell assemblies in the processing of olfactory words. These distributed neuron populations extend into language areas but also reach some parts of the olfactory system. These distributed neural systems may be the basis of the processing of language elements, their related conceptual and semantic information and the associated sensory information.

Amygdala↗
PubMed2005

Perception without a thalamus how does olfaction do it?

The olfactory system has generated considerable interest in recent years, mainly focused on receptor genes and early olfactory processing. In this issue of Neuron, Mori et al. focus centrally, providing evidence for slow- and fast-wave states in olfactory cortex that appear to gate the inflow of information underlying conscious smell perception.

Olfactory Bulb↗
PubMed2005

A truffle in the mouth is worth two in the bush: odor localization in the human brain.

It is widely thought that locating the source of a smell is an ability best left to nonhuman members of the animal kingdom. In this issue of Neuron, two complementary articles highlight the neural mechanisms underlying the localization of an odor, either to the left or right side of the nose (Porter et al.) or to the inside or outside of the mouth (Small et al.). Together, these studies validate the idea that the human brain is equipped with the apparatus necessary to pinpoint the location of an odor source.

Animals↗
PubMed2005

Olfactory preference and Fos expression in the accessory olfactory system of male rats with bilateral lesions of the medial preoptic area/anterior hypothalamus.

In the present study we evaluated if a medial preoptic area/anterior hypothalamus lesion affects the olfactory preference toward soiled bedding from receptive females in comparison to bedding from anestrous females or clean bedding. In the second part of the study we evaluated the accessory olfactory system response to estrous bedding with Fos immunoreactivity to determine if the preoptic lesions modify the processing of sexually relevant olfactory cues. Before medial preoptic area/anterior hypothalamus lesions, male rats spent more time investigating estrous bedding as opposed to anestrous or clean bedding. After the lesion, subjects showed no preference between estrous and anestrous bedding; that is, males spent the same amount of time investigating both types of bedding. These two odors were investigated more than clean bedding. Increments in Fos immunoreactivity neurons were seen in structures of the accessory olfactory system after exposure to soiled estrous bedding [granular layer of the accessory olfactory bulb, anterior-dorsal medial amygdala, posterior-dorsal medial amygdala, bed nucleus of the stria terminalis]. These results suggest that bilateral destruction of the medial preoptic area/anterior hypothalamus modify male olfactory preference in such a way that subjects spend the same time smelling and investigating bedding from estrous and anestrous females. This change in olfactory preference is not associated with alterations in the processing of sexually relevant olfactory cues by the accessory olfactory system.

Animals↗
PubMed2004

Basic anatomy and physiology of olfaction and taste.

The chemical senses of taste and smell are important to survival and quality of life. Both senses rely on the binding of odorant molecules to receptors located on the receptor cells. Olfaction and gustation have complex systems of coding, but they display differing methods for coding the receptor stimulus. Both have numerous central projections that allow for the perception and interpretation of these important sensory inputs.

Chemoreceptor Cells↗