Biomedical subjects

R L Doty

Publications and source records attributed to R L Doty.

At least 19 recordsLinked to original sources

PubMed1992

Lack of major olfactory dysfunction in MPTP-induced parkinsonism.

The olfactory function of 6 patients whose parkinsonism was the result of intravenous administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was compared to that of 12 age-matched patients with idiopathic Parkinson's disease (PD) and 10 age-matched normal control subjects. Unlike their PD counterparts, the olfactory test scores of patients with MPTP-induced parkinsonism did not differ significantly from those of control subjects. These findings suggest that MPTP-induced parkinsonism, unlike idiopathic PD, is unaccompanied, on average, by major alterations in the ability to smell.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1992

Influences of hypothyroidism on the taste detection performance of rats: a signal detection analysis.

The influences of hypothyroidism on behavioral measures of the taste function in male and female Long-Evans rats were determined. Experimental rats' preferences for and ability to detect NaCl, HCl, sucrose, and quinine sulfate were examined before, during, and after 9 weeks of maintenance on 0.1% propylthiouracil (PTU), an agent that produces marked hypothyroidism, with similar determinations made for control animals. Despite significant decreases in PTU-treated rats' serum triiodothyronine (T3) and thyroxin (T4), there were no changes in sensitivity or responsivity to the target tastants. However, altered preferences for NaCl, HCl, and quinine sulfate were observed for PTU-treated rats; elevated consumption of HCl and quinine sulfate was present at the end of the study when serum T3 and T4 had returned to near-baseline levels. The data confirm observations that PTU-induced hypothyroidism alters rats' taste preference behavior.

Animals↗

PubMed1992

Bilateral olfactory dysfunction in early stage treated and untreated idiopathic Parkinson's disease.

Decreased olfactory function is among the first signs of idiopathic Parkinson's disease (PD). Whether such dysfunction is present to the same degree on both sides of the nose, however, is unknown. Furthermore, whether the deficit results from or is influenced by anti-Parkinsonian medications has not been definitely established. Odour identification ability was evaluated on the left and right sides of the nose in 20 early-stage untreated PD patients, 20 early-stage treated PD patients, and 20 controls. In all cases, the PD related olfactory dysfunction was bilateral and no difference was observed between the test scores of patients taking or not taking drugs for PD. Although asymmetries of unsystematic direction were present in the test scores of some PD patients, similar asymmetries were observed in the controls and the asymmetries were not related to the side of the major motor dysfunction. As in earlier work, no relation was present between the olfactory test scores and the degree of tremor, rigidity, bradykinesia, or gait disturbance at the time of testing. These findings indicate that the olfactory dysfunction of early stage PD is robust, typically of the same general magnitude on both sides of the nose, and uninfluenced by anti-Parkinsonian medications.

Age Factors↗

PubMed1992

Chemical senses.

Explore the source record for details and available documents.

Humans↗

PubMed1991

Smell and taste disorders, a study of 750 patients from the University of Pennsylvania Smell and Taste Center.

Smell and taste disorders are common in the general population, yet little is known about their nature or cause. This article describes a study of 750 patients with complaints of abnormal smell or taste perception from the University of Pennsylvania Smell and Taste Center, Philadelphia. Major findings suggest that: chemosensory dysfunction influences quality of life; complaints of taste loss usually reflect loss of smell function; upper respiratory infection, head trauma, and chronic nasal and paranasal sinus disease are the most common causes of the diminution of the sense of smell, with head trauma having the greatest loss; depression frequently accompanies chemosensory distortion; low body weight accompanies burning mouth syndrome; estrogens protect against loss of the sense of smell in postmenopausal women; zinc therapy may provide no benefit to patients with chemosensory dysfunction; and thyroid hormone function is associated with oral sensory distortion. The findings are discussed in relation to management of patients with chemosensory disturbances.

Burning Mouth Syndrome↗

PubMed1991

Influence of adrenalectomy on the odor detection performance of rats.

The influence of adrenalectomy (ADX) on the odor detection performance of male Long-Evans rats was assessed using high-precision olfactometry and a go/no-go operant signal detection task. Nonparametric signal detection measures of sensitivity and responsivity, as well as measures of S+ response latency, the number of aborted trials, and session time, were obtained in daily 250-trial test sessions prior to and after adrenalectomy. Four ADX animals were tested using the odorant pyridine, three using the odorant eugenol, and two using the odorant ethyl acetate. Nine other rats served as sham-operated controls. Neither odor detection nor related nonsensory performance measures were influenced by adrenalectomy or sham-operation procedures. These results imply that adrenalectomy has little or no influence on the odor detection performance of the rat.

Adrenal Cortex↗

PubMed1991

Olfactory capacities in aging and Alzheimer's disease. Psychophysical and anatomic considerations.

Age-related alterations in the ability to smell are well documented. For example, more than three-fourths of individuals over the age of 80 have major difficulty detecting and identifying odors. Furthermore, olfactory dysfunction is among the first signs of Alzheimer's disease (AD). Indeed, the olfactory pathways of patients with AD evidence disproportionate numbers of neuritic plaques and neurofibrillary tangles relative to other sensory pathways, suggesting that the olfactory system may be the site of first involvement of the AD process. In this article, the literature related to age- and AD-related alterations in olfactory perception has been briefly reviewed, and several current hypotheses regarding the physiologic basis for these changes discussed.

Aged↗

PubMed1991

Odor identification deficit of the parkinsonism-dementia complex of Guam: equivalence to that of Alzheimer's and idiopathic Parkinson's disease.

Olfactory dysfunction is among the first signs of Alzheimer's disease (AD), idiopathic Parkinson's disease (PD), and the parkinsonism-dementia complex (PDC) of Guam. We have recently demonstrated that the odor identification and detection deficits of patients with PD are equivalent to those of patients with mild AD when subtle differences in cognitive function are statistically controlled for by analysis of covariance. In contrast, patients with progressive supranuclear palsy (PSP) and patients with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism evidence olfactory function much more similar to that of normal controls. In the present study, we administered the University of Pennsylvania Smell Identification Test and the Picture Identification Test to 24 patients with early signs of the PDC of Guam and statistically compared their test scores to those of 24 early-stage AD and 24 early-stage PD patients of similar age and gender from the United States mainland. Although the PDC group evidenced slightly more difficulty in identifying pictures than did the other 2 groups, the odor identification deficit associated with this disorder was of the same magnitude as that observed in AD and PD, suggesting that olfactory testing cannot be used to distinguish among these 3 diseases and that the olfactory dysfunction of these disorders may reflect a common neurologic substrate.

Adult↗

PubMed1991

Olfactory dysfunction in three neurodegenerative diseases.

Adult↗

PubMed1990

Taste responses of dogs to ethylene glycol, propylene glycol, and ethylene glycol-based antifreeze.

Although it is widely believed that ethylene glycol-based antifreeze (AF) is an attractive tastant to dogs and other animals, empirical data on this point are not available. In experiment 1, we examined the propensity of 178 adult mixed-breed dogs to approach, sniff, and lick a concentration of AF commonly used in automotive cooling systems (50%). Despite the fact that most of the dogs approached and sniffed the AF in these 5-minute tests, only 9% initiated lick responses and most of these were brief and not followed by additional licking. In experiment 2, the lick responses of five gastric-cannulated dogs to aqueous solutions of 20% sucrose, 50% ethylene glycol, 50% propylene glycol, water, and 50% AF were examined in 14-minute tests before and after periods of food and water deprivation. Under the latter conditions, 2 of the 5 dogs drank amounts of ethylene glycol that would have been lethal to uncannulated dogs. None of the five dogs drank potentially lethal amounts of AF. The preference order for these tastants was sucrose greater than water greater than ethylene glycol greater than AF = propylene glycol. Although these findings question the general belief that AF is highly palatable to most dogs, they do imply that large individual differences in responsiveness exist and that AF ingestion is likely influenced by motivational state. Furthermore, they suggest the possibility that unpleasant-tasting additives could be successfully developed to eliminate the ingestion of AF, because the initial attractiveness of AF is relatively low. Such additives would have to be stable in vehicular cooling systems and not adversely affect the functional aspects of AF performance.

Animals↗

PubMed1990

Human odor intensity perception: correlation with frog epithelial adenylate cyclase activity and transepithelial voltage response.

Although a number of odorants are hypothesized to depolarize frog olfactory receptor cells by binding to ciliary glycoproteins which activate membrane-bound G-proteins to induce adenylate cyclase-mediated increases in intracellular cAMP (cyclic adenosine 3',5'-monophosphate), it is not known whether these odorants influence human odor perception via similar mechanisms. In this paper we present evidence derived from odor attribute ranking and multidimensional scaling procedures that the perceived intensity of such odorants to humans is correlated with (a) the amount of adenylate cyclase activity they induce in an in vitro frog olfactory cilia preparation and (b) the magnitude of their influence on the frog transepithelial voltage response or electro-olfactogram (EOG). These observations are in accord with the hypothesis that the perception of the intensity of some odors by humans is associated with cAMP-related epithelial processes and imply that remarkable homologies exist between the intensity-related olfactory receptor mechanisms of frog and man.

Adenylyl Cyclases↗

PubMed1990

Dose-related effects of cigarette smoking on olfactory function.

Little is known about the influence of cigarette smoking on the ability to smell; previous studies on this topic have led to contradictory findings and have failed to take into account smoking dose and duration. In the present study, the 40-odorant University of Pennsylvania Smell Identification Test was administered to 638 subjects for whom detailed smoking histories were available. Smoking was found to be adversely associated with odor identification ability in a dose-related manner in both current and previous cigarette smokers. Among previous smokers, improvement in olfactory function was related to the time elapsed since the cessation of smoking. Logistic regression analysis found current smokers to be nearly twice as likely to evidence an olfactory deficit than persons who have never smoked. Overall, the data suggest that (1) smoking causes long-term but reversible adverse effects on the ability to smell and (2) the failure of some studies to demonstrate smoking effects may be caused by the inclusion of persons with a history of smoking in the nonsmoking groups.

Adolescent↗

PubMed1990

Fluprazine hydrochloride: no influence on the odor detection performance of male rats.

Fluprazine hydrochloride (DU 27716) decreases copulatory and offensive attack behaviors of male rats and increases their latency to locate buried food in an open field. Since such behaviors are mediated to some degree by the olfactory system, several investigators have hypothesized that this drug may produce an overall impairment in olfactory sensitivity. To test this hypothesis, the influences of five doses of fluprazine hydrochloride (1.0, 2.5, 5.0, 7.5 and 10.0 mg/kg IP) on the odor detection performance of 12 adult male Long Evans rats was assessed, relative to saline, using high precision olfactometry and a go/no-go operant odor detection task. Treatments were administered every 3rd day in counterbalanced order, with the drug or saline injections occurring 30 minutes before the 260-trial test sessions. No significant influence of fluprazine was observed on odor detection performance, as measured by the nonparametric signal detection sensitivity index SI and the percentage of correct trials. These results indicate that fluprazine does not induce generalized olfactory impairment.

Animals↗

PubMed1990

A comparison of response characteristics of airflow and pressure transducers commonly used in rhinomanometry.

Although the ranges in which pneumotachographs evidence linear output to static flows are documented in the literature, measures of output reliability or the stability of calibration functions resulting from the input of dynamic nonsinusoidal flows (such as those which occur during nasal breathing) have not been investigated. Furthermore, it is not known whether the type of requisite pressure transducer used in conjunction with the pneumotachograph influences the pneumotachograph's linearity, output reliability, or dynamic response. To provide information on these points, we determined the dynamic and static responsiveness of three pneumotachographs commonly used in rhinomanometry, in combination with three requisite pressure transducers. In general, a) output reliability depended on the pneumotachograph/pressure transducer combination and was not readily predictable from the reliabilities of the individual components, b) heating increased pneumotachograph reliability, and c) differences in accuracy existed among transducer combinations at high, but not low, flow frequencies. In addition, results from the calibration syringe study (in which the pneumotachograph is calibrated with dynamic non-sinusoidal flows) suggested that: a) a single calibration factor, as supplied by most pneumotachograph manufacturers, is inadequate for accurately measuring the full range of flows produced in sniffing and breathing tasks; b) the measurement of complex waveforms, even when the dominate frequencies of such waveforms are low, requires pneumotachographs that accurately respond to relatively high frequencies; and c) the use of dynamic nonsinusoidal flows (as opposed to static flows) to calibrate pneumotachographs results in a calibration function with higher reliability.

Calibration↗

PubMed1989

The olfactory and cognitive deficits of Parkinson's disease: evidence for independence.

In the present study we sought to determine whether the olfactory deficits of parkinsonism are related to the cognitive and perceptual-motor manifestations of the disease. Pearson correlation coefficients were computed among a number of olfactory, neurological, and neuropsychological measures obtained from 58 Parkinson's disease patients, including the University of Pennsylvania Smell Identification Test, a modified Randt memory test, a reaction time test, a finger-tapping test, ratings of motor and neurological function, and selected verbal and performance subtests of the Wechsler Adult Intelligence Scale--Revised. Data from 38 patients with Parkinson's disease who received odor detection threshold testing were also evaluated. The intercorrelation matrix was subjected to a principal components factor analysis which yielded six clear-cut factors: cognitive/memory, gross motor, oral motor, fine motor, olfactory, and tremor. The olfactory factor received strong and nearly exclusive loadings from the olfactory measures (which did not evidence meaningful loadings on any of the other factors). A ten-trial jackknife procedure revealed the factor structure to be stable. Further support of the independence of the olfactory variables from the other measures was provided by multiple regression and canonical correlation analyses. Overall, these findings lend support to the hypothesis that the olfactory disorder of parkinsonism is independent of the cognitive, perceptual-motor, and memory manifestations of the disease.

Aged↗

PubMed1989

Influence of the D-2 dopamine receptor agonist quinpirole on the odor detection performance of rats before and after spiperone administration.

The influence of five doses of the D-2 receptor agonist quinpirole (0.025, 0.05, 0.075, 0.10, and 0.20 mg/kg IP) on the odor detection performance of 21 adult male Long Evans rats was assessed using high precision olfactometry and a go/no-go operant task. Additionally, ten rats were pre-treated with the D-2 receptor antagonist spiperone (0.62 mg/kg IP) and their performance monitored following quinpirole administration. Treatments were administered every third day in a counterbalanced order, with the quinpirole injections occurring 15 min before, and the spiperone injections 35 min before, the 260-trial test sessions. Quinpirole injection resulted in a dose-dependent decrease in odor detection performance, as measured by the percentage of correct trials and by the non-parametric signal detection sensitivity index SI. Prior treatment with spiperone eliminated these effects. Dose-related influences of quinpirole on (a) the average latency to initiate a detection response (i.e., the S + response latency), (b) the total session duration, and (c) the number of aborted trials were also eliminated or greatly attenuated by prior spiperone injection. These results suggest that D-2 receptors may be involved in the modulation of odor detection performance and related behaviors.

Acetates↗

PubMed1989

No influence of adrenalectomy on measures of taste sensitivity in the rat.

The influence of adrenalectomy on the taste sensitivity and responsivity of Long-Evans rats to sodium chloride and sucrose tastants presented separately and in mixtures was examined using high precision gustometry, computer-controlled go/no-go operant procedures, and nonparametric signal detection measures. Relative to baseline levels, adrenalectomized rats' plasma corticosterone levels decreased by 328% while sodium chloride and water consumption increased by 548% and 165%, respectively. The same measures remained unchanged in sham-operated animals. Taste sensitivity and responsivity to sodium chloride and sucrose did not differ between adrenalectomized and sham-operated animals and discrimination performance remained the same between the groups as well. The present results support and extend previous findings that adrenalectomy and the resultant corticosteroid deficiency does not influence taste sensitivity or responsivity in the rat.

Adrenal Cortex↗

PubMed1989

Influence of adult castration on the olfactory sensitivity of the male rat: a signal detection analysis.

The effect of adult castration on the male rat's ability to detect ethyl acetate odor was measured with high-precision olfactometry and a go-no-go signal detection task. Castration was found to significantly mitigate the tendency observed in sham castrates to improve detection performance across an 18-week postoperative test period. No significant castration-related alterations on the responsivity or S+ response latency measures were observed. These findings indicate that castration influences the male rat's ability to improve odor detection performance over time, although it is not known whether this effect is attributable to sensory or to memory mechanisms.

Animals↗