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PubMed1997

Sexually arousing events and relapse to heroin-seeking in sexually experienced male rats.

We have shown previously, using a reinstatement procedure, that both priming injections of heroin and exposure to footshock stress reinstate heroin-taking behavior following prolonged drug-free periods. In the present study, we examined the effect of another highly arousing event, exposure to a sexually active female, on reinstatement of heroin-seeking. Male rats were first given sexual experience, being allowed to copulate on 4 occasions with sexually active females and were then trained to self-administer heroin (100 micrograms/kg per infusion, IV) for 4 3-h sessions/day for 5-6 days and 1 6-h session/day for an additional 6 days. Extinction sessions were then given for 4 days, 6-h/day, during which saline was substituted for heroin. On tests for reinstatement, males were presented with: 1. The wire-mesh side of an empty cage (baseline condition), 2. the sight, odor, and smell of a sexually inactive female, 3. the sight, odor, and smell of a female in heat, 4. a female in heat, and allowed to copulate, 5. intermittent footshock (15 min, 0.5 mA, 0.5 s on, mean off period of 40 s), or 6. a priming injection of heroin (0.25 mg/kg, SC). Reinstatement of heroin-taking behavior was observed after exposure to the priming injection of heroin and to footshock stress. Reinstatement of heroin-taking behavior was not induced by exposure to the females in any of the conditions. Thus, motivational arousal, as such, does not appear to be a sufficient stimulus for relapse to heroin-taking.

Animals↗
PubMed2002

Not all 'predator odours' are equal: cat odour but not 2,4,5 trimethylthiazoline (TMT; fox odour) elicits specific defensive behaviours in rats.

The behavioural responses to two commonly used 'predator odours' were assessed in male Wistar rats. Cat odour was presented to rats in the form of a piece of collar that had been worn by a domestic cat. Fox odour was presented in an equivalent piece of (unworn) collar that had been impregnated with 2,4,5 Trimethylthiazoline (TMT)-an extract of fox faeces. Other rats were exposed to collars containing Triethylamine (TEA), a putrid fishy smell, or formaldehyde, which has an acrid irritating smell. Experiment 1 showed that rats approached cat odour, TMT and TEA significantly less than they did an unworn collar. However, only cat odour increased retreat to the hide box, reduced locomotor activity and elicited 'head out' behaviour. When tested immediately after odour exposure, only cat odour exposed rats showed increased anxiety in the elevated plus maze and suppressed activity in a 90-min general activity test. When returned to the odour-paired environment 24 h later in the absence of test odours, only rats that had previously received cat odour showed evidence of conditioned fear. Experiment 2 showed that rats given the benzodiazepine drug midazolam (0.5 mg/kg) display increased approach and decreased defensiveness towards a cat odour impregnated collar. In contrast, midazolam accentuated the avoidance of TMT and formaldehyde containing collars. Experiment 3 showed that when cat odour was presented in a small, enclosed environment, rats display increased body immobility, decreased grooming and increased orientation towards the odour-exuding stimulus. These responses were not seen with TMT or TEA containing collars. Taken together, these results suggest that while cat odour strongly elicits specific defensive behaviours in rats, TMT has effects that are more characteristic of an aversive odour. We suggest that the results of some previous studies using TMT may need to be reassessed.

Animals↗
PubMed2000

Structure of the principal olfactory tract.

Although the purpose and importance of the sense of smell in human beings has not been totally clarified, it is one of the principal information channels in macrosmatic animals. It was the first long-distance information system to have appeared in phylogenetic evolution. The objective of this article is to deepen the knowledge of the pathways that join the olfactory epithelium with the cortical olfaction areas, to better understand olfactory dysfunction in human beings. Differential staining and marking techniques were applied to histologic sections obtained from 155 animals of different species, to study the different connections existing among olfactory tract components. Our study of the connections between the olfactory mucosa and the principal olfactory bulb deserves special mention. The distribution of second neuron connections of the olfactory tract with the central nervous system is quite complex and diffuse. This indicates an interrelation between the sense of smell and a multitude of functions. These connections seem to be of different quantitative importance according to species, but qualitatively they exist in both human beings and other macrosmatic animals.

Animals↗
PubMed2003

Preexposure to the stimulus elements, but not training to detect them, retards human odour-taste learning.

Odours are judged to smell sweeter following simultaneous oral pairings with the tastant sucrose and sourer after parings with the tastant citric acid. This effect may result from human participants perceiving and encoding a unitary odour-taste percept. This study examined two factors thought likely to disrupt such encoding; (a) preexposure to the mixture elements and (b) training to spot the elements of taste-odour mixtures. Half of the participants were trained to identify tastes and smells and half received no training. All participants were preexposed to two odours (A, B) and two tastes (X, Y), followed by pairings of these stimuli (AX, BY) and then by pairings between two non-preexposed odours and the same tastes (CX, DY). This process was then repeated on a second session. Odour-taste learning was retarded following preexposure, but was unaffected by training. These findings suggest; (1) that odour-taste mixtures may be cognitively impenetrable and (2) that preexposure leads to encoding of A and B, which are then resistant to interference when further pairings are presented (i.e. AX, BY).

Journal Article↗
PubMed2003

Human volunteer study with PGME: eye irritation during vapour exposure.

The objective of this study was to establish the possible occurrence of eye irritation and subjective symptoms in human volunteers exposed to propylene glycol monomethyl ether (PGME) vapour at concentrations of 0, 100 and 150 ppm. Testing was conducted in 12 healthy male volunteers using a repeated measures design. Each subject was exposed for 2.5 h to each of the three exposure conditions that were spaced 7 days apart. The exposure sequences were counterbalanced and the exposure to the test substance and the effect measurements were conducted in a double-blind fashion. During all exposure sessions, 20 ppm diethyl ether was used as a 'masking agent' for vapour exposure. Measurements of pre- and post exposure eye redness, corneal thickness, tear film break-up time, conjunctival epithelial damage, blinking frequency, and subjective ratings on discomfort were used to evaluate the possible irritating effects of PGME. The results indicated no significant treatment effects for any of the objective parameters. Results of the subjective ratings indicated very slight effects on the eyes in the 150 ppm PGME condition only. No significant effects of treatment were found for the remaining questions concerning the perceived intensity of the smell in the room, the (un)pleasantness of the smell, the perceived effects on the skin, effects on the throat, shivering, muscle aching, and intestinal cramps. In conclusion, the results of the present study indicated minimal subjective eye effects at 150 ppm only, and no impact on the objective measures of eye irritation at either of the two exposure levels. It was concluded that the no adverse effect concentration for eye irritation due to PGME vapour was at least 150 ppm.

Adult↗
PubMed2003

Screening of traditionally used South African plants for antifungal activity against Candida albicans.

Twenty-four South African medicinal plants were screened against Candida albicans standard strain ATCC 10231 and two clinical isolates from a 5-month-old baby and an adult, in an attempt to find a traditional remedy to treat oral candidiasis, which is prevalent in HIV-patients. Allium sativum L. and Tulbaghia violacea L. aqueous bulb extracts had MIC values of 0.56 and 3.25mg/ml respectively, whilst Polygala myrtifolia L. leaves and Glycyrrhiza glabra L. rhizome extracts had MIC values of 1.56 mg/ml when tested against the 5-month-old isolate. Fresh water extracts stored at 4, 23 and 33 degrees C over a period of a week, were used to determine the stability of these extracts. Allium sativum and Tulbaghia violacea maintained activity at 4 degrees C, but not at higher temperatures, whereas Polygala myrtifolia and Glycyrrhiza glabra lost activity within a day even at 4 degrees C. The unpleasant taste of the two species with a garlic smell, could however not be masked, and as the smell following the eating of the two species would lead to HIV-patients being recognised, these two plants where not considered for further investigation. Therefore, Polygala myrtifolia and Glycyrrhiza glabra are being further investigated for use as an oral mouthwash in clinics and homes.

Adult↗
PubMed2000

Comparison of the composition of some petroleum samples which may be applied for skin and mucous membrane treatment.

A particular Croatian petroleum (sample P1) and its three derivatives (samples P2, P3 and P4), potentially applied as healing preparations for skin and mucous membrane treatment, were studied in order to learn their composition and to discriminate them according to two criteria: composition of natural petroleum compounds, and lacking aromatics. Elemental (C, H, N and S) and group composition (by LC, UV/VIS, IR and 1H NMR) were determined and the single component distributions were analyzed (by GC) and identified (by GC-MS). Focussed saturated compounds (n-alkanes, pristane and phytane, drimanes/eudesmanes, steranes and hopanes) were studied in order to emphasize the preservation or destruction of genuine petroleum structures in derivatives. Samples P2 (petroleum-brownish color, petroleum like smell) and P3 (colorless, transparent, slight pine-like odor), were found, now constituting petroleum, to still be composed of the components of their native structure. Compared to sample P1, they were missing light and heavy compounds. While sample P2 contained different compound classes, sample P3 comprised exclusively saturated hydrocarbons, satisfying pharmacopoeia's requirement regarding the low aromatics content. Almost a half of sample P3 was composed of cyclic moieties, including terpenoids, possibly responsible for the odor. Samples P1, P2 and P3 were found rather rich in steranes. Sample P4 (colorless, transparent, no smell) was found denaturalized. In spite of high similarity in bulk properties to sample P3, it comprised no detectable amount of n-alkanes, pristane and phytane, or drimanes/eudesmanes, steranes and hopanes (although found rich in oligocycles).

Administration, Topical↗
PubMed2004

Olfactory identification and WAIS-R performance in deficit and nondeficit schizophrenia.

INTRODUCTION: An expanding database supports the notion that the deficit syndrome (DS) is a discrete condition within schizophrenia and recent data argues that Smell Identification Deficits (SID) may have a primary relationship with its pathophysiology. If so, then the relationship of University of Pennsylvania Smell Identification Test (UPSIT) scores with other neurocognitive measures in DS patients may point to the neural substrate of the deficit syndrome. METHOD: We examined the relationship of UPSIT scores and Wechsler Adult Intelligence Scale-Revised (WAIS-R) performance in 46 DSM-IV schizophrenia patients. The Schedule for the Deficit Syndrome (SDS) interview was used to subgroup the sample into 13 DS and 33 nondeficit syndrome (NDS) patients. RESULTS: DS and NDS groups had similar mean ages, age of onset, and GAF scores, but DS patients had fewer years of education. DS and NDS patients also did not differ in full scale, verbal or performance IQ or in any WAIS-R subtest. However, UPSIT scores were significantly worse in the DS patients, most of whom met criteria for a clinically meaningful olfactory impairment. In DS patients, UPSIT scores were significantly correlated with Performance IQ, Block Design, and Object Assembly, all of which are associated with complex visual-motor organizational function thought to be mediated by parietal circuitry. UPSIT scores in NDS patients were significantly related with Vocabulary, Similarities, and Digit Symbol subtests, which are indicative of verbal functioning. CONCLUSION: These preliminary data support previous findings suggesting that in addition to frontal neuropsychological abnormalities, DS patients may have greater performance impairments on tasks associated with parietal functioning. Our findings furthermore suggest that the parietal circuitry may be a conspicuous substrate for impaired odor identification ability in these patients. The lesser abnormalities in UPSIT ability in NDS patients may be attributed to verbal ability. These data are preliminary and further investigations with larger samples are needed to support our findings.

Adult↗
PubMed2001

Fullerene modified supported lipid membrane as sensitive element of sensor for odorants.

A supported lipid bilayer membrane (s-BLMs) formed on a freshly cleaved metallic surface by the Tien method was applied for the design of an electrochemical sensor for detection of neutral odorant molecules. The lipid bilayer was modified by saturation with fullerene C(60), which possesses electron mediator properties and facilitates a redox reaction occurring at the border of the lipid membrane and metal surface. I(2)/I(-) and ferrocenyl trimethyl bromide were used as electroactive marker ions. The smell compounds adsorb on the surface of the lipid layer and change its structure. As a consequence the ratio of marker ion penetration to the lipid membrane is altered. The magnitude of these changes depends on the amount and chemical structure of adsorbed molecules. The research presented was carried out by cyclic voltammetry. The magnitude of the electrochemical signal generated by smell compounds was correlated with other parameters describing their molecular properties such as: octanol/water partition coefficients and dipole moments.

1-Octanol↗
PubMed1999

Evaluation and attributional analysis of an aromatherapy service for older adults with physical health problems and carers using the service.

OBJECTIVE: To evaluate an aromatherapy service for older adults with physical health problems and their carers. The aromatherapy service was based in a carer support unit at a hospital in Birmingham. The research question was, 'What types of benefits do clients/carers report from aromatherapy?' DESIGN: Qualitative analysis of interview scripts and written descriptions. SETTING: The interviews were carried out either at the carer support unit, at a connected day centre or at the client/carer's home. PARTICIPANTS: The participants were six clients and four carers who were in contact with the carer support unit and had received aromatherapy from the aromatherapist in the past year. MAIN OUTCOME MEASURES: The participants were interviewed using a semi-structured questionnaire to explore which part of a session they liked best, perceived benefits of aromatherapy and a smell attribution to certain essential oils. The aromatherapist was also asked to write descriptions of her perceived benefits for the clients and carers. The interviews were analysed qualitatively and compared to the aromatherapist's written descriptions. RESULTS: All clients and carers said they benefited from the aromatherapy and felt more relaxed after a session. The qualitative analysis revealed a 70% area of overlap and a 30% 'hidden' area of congruence. The smell analysis revealed individual differences in attribution depending on past experience and expectation of oil presented. CONCLUSION: The findings of this evaluation suggest the aromatherapy service offered was valuable to clients and carers and their perception of its benefits for them were largely congruent with those of the aromatherapist.

Aged↗
PubMed2001

Animal cognition and the rat olfactory system.

Is smell a 'primitive' sense used primarily to guide biologically basic behaviors or might it be the sensory modality that allows some species to express complex learning and other forms of cognitive behavior? Historically, the olfactory system has been considered primitive and it is not surprising that, until recently, cognitive neuroscientists have ignored odor-guided behavior. However, we now know that the olfactory system has projections to the prefrontal cortex, entorhinal cortex and hippocampus, and that these connections support the acquisition of simple and higher-order instrumental tasks, as well as a robust memory for odors. It appears that animals with a well-developed sense of smell have the neural machinery to think with their noses.

Journal Article↗
PubMed2003

Multivariate mixed inheritance models for QTL detection on porcine chromosome 6.

A series of multivariate mixed-inheritance models is fitted to the data from an outbred-line pig cross commercially used in Norway. Each model accommodates information on polygenic (co)variances between F2 individuals and their F1 parents across the five traits through incorporation of a random animal effect. Considered traits relate to meat quality and are chosen following up the results from a previous evaluation, in which a putative quantitative trait locus (QTL) was identified on chromosome six that affects the amount of intramuscular fat (IMF), meat percentage, meat tenderness and smell intensity (Grindflek et al., 2001). An additional trait included in the model, based on results of other studies, is the backfat thickness. The analysed material comprises data scored for 305 F2 individuals, whereas marker information is available for F1 and F2 generations. Based on the results of the multivariate analysis with the mixed-inheritance model, it was possible to conclude that the evidence for QTLs for meat percentage, meat tenderness and smell intensity in the study of Grindflek et al. (2001) do not represent separate QTLs, but is caused by the fact that the applied pre-adjustment of trait values for polygenic effects failed properly to remove the polygenic variation. The QTL effect on IMF on chromosome six was confirmed.

Animals↗
PubMed1986

Frequency of self-reported 'anxiolytic withdrawal' symptoms in a group of female students experiencing anxiety.

This study describes the occurrence of self-reported perceptual phenomena in students experiencing anxiety. Phenomena like hypersensitivity to touch, hyposensitivity to taste and smell, and unusual tastes and smells appear to be non-specific and to be closely related to the level of anxiety. They emphasize the need for the development of techniques to elicit perceptual phenomena, and to investigate their occurrence and the intensity of their phenomena in variously defined groups. These also have implications for the assessment of benzodiazepine withdrawal syndromes.

Adult↗
PubMed2001

Evaluation of key aroma compounds in hand-squeezed grapefruit juice (Citrus paradisi Macfayden) by quantitation and flavor reconstitution experiments.

Twenty-five odor-active compounds were quantified in the fresh, hand-squeezed juice of White Marsh seedless grapefruits using stable isotope dilution assays. By calculation of the odor activity values of the odorants (ratio of their concentrations in the juice to their odor thresholds in water) it was shown that the fruity esters ethyl 2-methylpropanoate, ethyl butanoate, and (S)-ethyl 2-methylbutanoate, and the fruity, sweet winelactone, as well as the grassy smelling (Z)-hex-3-enal, and trans-4,5-epoxy-(E)-dec-2-enal with metallic odor, were among the most potent odorants of the fresh grapefruit juice. The typical sulfurous, grapefruit-like odor quality was mainly due to the catty, blackcurrant-like 4-mercapto-4-methylpentan-2-one and the grapefruit-like smelling 1-p-menthene-8-thiol. These findings were confirmed by reconstitution experiments to simulate the aroma of the fresh grapefruit juice.

Acetaldehyde↗
PubMed2001

Prediction of the aroma quality and the threshold values of some pyrazines using artificial neural networks.

An artificial neural network is used to predict both the classification of aroma compounds and their flavor impression threshold values for a series of pyrazines. The classification set consists of 98 compounds (32 green, 43 bell-pepper, and 23 nutty smelling pyrazines), and the regression sets consist of 24 green and 37 bell-pepper odorous pyrazines. The best classification of the three aroma impressions (93.7%) is obtained by using a multilayer perceptron network architecture. To predict the threshold values of bell-pepper fragrance, a standard Pearson R correlation coefficient of 0.936 for the training set, 0.912 for the verification set, and 0.926 for the test set is received with two hidden layers consisting of two and one neurons. The network for the threshold prediction of the class of green-smelling pyrazines with one hidden layer containing three neurons turns out to be the best with a standard Pearson R correlation coefficient of 0.859 for the training, 0.918 for the verification, and 0.948 for the test set. These good correlations show that artificial neural networks are versatile tools for the classification of aroma compounds.

Flavoring Agents↗
PubMed2002

1-Octen-3-ol together with geosmin: new secretion compounds from a polydesmid millipede, Niponia nodulosa.

The small millipede Niponia nodulosa (Polydesmida: Cryptodesmidae) emits an earthy smell when disturbed. This smell was obtained from hexane extracts from both sexes at the sixth and seventh instars and adult stages, and was found by GC/MS analyses to be composed of two compounds, 1-octen-3-ol as the major component and geosmin as the minor component. This is the first report of these compounds in secreted substances from millipedes. As they showed little repellent activity against foraging ants in bioassays, their biological function as defensive allomones was not clearly elucidated. However, both compounds provoked negative chemotaxis of conspecific millipedes in a Y-tube olfactometer, especially 1-octen-3-ol, which was active at a dose equivalent to the content of a single millipede. Such biological activity suggests that this compound is involved in intraspecific communication in this millipede and may play a role as an alarm pheromone.

Animal Communication↗
PubMed2004

Marijuana odor perception: studies modeled from probable cause cases.

The 4th Amendment of the United States Constitution protects American citizens against unreasonable search and seizure without probable cause. Although law enforcement officials routinely rely solely on the sense of smell to justify probable cause when entering vehicles and dwellings to search for illicit drugs, the accuracy of their perception in this regard has rarely been questioned and, to our knowledge, never tested. In this paper, we present data from two empirical studies based upon actual legal cases in which the odor of marijuana was used as probable cause for search. In the first, we simulated a situation in which, during a routine traffic stop, the odor of packaged marijuana located in the trunk of an automobile was said to be detected through the driver's window. In the second, we investigated a report that marijuana odor was discernable from a considerable distance from the chimney effluence of diesel exhaust emanating from an illicit California grow room. Our findings suggest that the odor of marijuana was not reliably discernable by persons with an excellent sense of smell in either case. These studies are the first to examine the ability of humans to detect marijuana in simulated real-life situations encountered by law enforcement officials, and are particularly relevant to the issue of probable cause.

Adult↗
PubMed2003

Social relations and breath odour.

In this retrospective qualitative study, the researcher reviewed 55 client records of The Breath Odour Clinic. The purpose was to determine if individuals attended a clinic specialised in treating oral malodour for medical or social reasons. The study focused on the psychosocial and breath odour history. Clients had agreed to the use of information for research purposes. Society uses odour as a means to define and interact with the world. The olfactory, smelling experience is intimate, emotionally charged and connects us with the world. It follows that the smell from mouth breath odour can connect or disconnect a person from their social environment and intimate relationships. How one experiences one's own body is very personal and private but also very public. Breath odour is public as it occurs within a social and cultural context and personal as it affects one's body image and self-confidence. Body image, self-image and social relations mesh, interact and impact upon each other. Breath odour is a dynamic and interactive aspect of the self-image. In addition, breath odour may be value-coded as 'bad'. In 75% of the cases reviewed, decreased self-confidence and insecurity in social and intimate relations led clients to seek treatment at the specialised breath odour clinic. Their doctor, dental hygienist or dentist had treated medical and oral conditions but not resolved their breath odour problem. When a person perceives a constant bad breath problem, she/he uses defence techniques, and may avoid social situations and social relations. This affects a person's well-being.

Adolescent↗