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W W Spirduso

Publications and source records attributed to W W Spirduso.

18 recordsLinked to original sources
PubMed1992

Tolerance to the effects of ethanol on the speed and success of reaction time responding in the rat: effects of age and intoxicated practice.

An animal model of human reaction time (RT) was used to investigate the effects of age and intoxicated practice on the development of tolerance to the motor impairing effects of ethanol (EtOH). Young (8-9 month) and old (24-26 month) Fischer 344 rats were trained to release a lever in response to an auditory and visual stimulus in order to avoid mild footshock. The animals were divided into groups to receive either intoxicated (EtOH-before) or unintoxicated (EtOH-after) RT testing. Successful avoidance and response latencies were impaired in young and old rats after the initial exposure to EtOH (EtOH-before group). Tolerance developed to EtOH's effects on successful avoidance and on response latencies whether or not the rats received intoxicated RT practice; however, intoxicated practice facilitated tolerance development to EtOH's effects on successful avoidance but not on response latencies. While the initial sensitivity and the level of tolerance that developed to EtOH's effects were similar in young and old rats, the old rats were generally more sensitive to EtOH and developed tolerance at a slower rate. These results suggest that tolerance develops to the effects of EtOH on RT and that intoxicated practice can have different effects on the parameters of the behavioral response.

Aging↗
PubMed1991

Age-related differences in response programming.

Age-related differential effects on reaction time (RT) performance for movement complexity and response-response (R-R) compatibility were examined in children, adolescents, and young adults. A two-choice RT paradigm involved three different finger responses, and each finger movement response was paired with every other movement response. Movement complexity was manipulated by varying the digits activated and was measured as the mean RT for a particular movement across all choice pairs. R-R compatibility was manipulated by altering the pairing of choice alternatives and was determined by the mean RT comparison for each of the movements according to the paired choice alternative. Simple RTs were also obtained for all finger movement responses for comparison with the RTs achieved in choice situations. Age-related differences were found for both movement complexity and R-R compatibility. Mean RT and response consistency improved with age. Although higher overall speeds were found with age, adolescents were not significantly slower than young adults. Adolescents did, however, make significantly fewer response errors on movements differing in complexity. Bilateral versus unilateral control and number of fingers involved in the task were found to affect both movement complexity and the compatibility between response pairs. The relationship between the alternative and choice response was found to be a robust factor affecting R-R compatibility. Choice responses were significantly slower than simple responses, and the rank ordering of movement responses was identical within the two paradigms.

Adolescent↗
PubMed1990

Effects of adult aging on the movement complexity factor of response programming.

The interaction effects between adult aging and incremental levels of movement complexity were studied in young, middle-aged, and older healthy females. Utilizing a two-choice reaction time (RT) paradigm, movement complexity as a factor of response programming was varied in a microswitch pressing task by altering the number of sides of the body and the number of fingers controlled. The speed of response programming was found to be age dependent and to interact with movement complexity across age groups. The results confirmed that as movement complexity increases, the effects of adult aging on RT increase. This study further emphasizes the robustness of the movement complexity x age effect, in that older individuals were found to be much more sensitive to small changes in movement complexity than younger subjects. The comparison results of three adult age groups suggested this sensitivity to movement complexity is progressive over the adult life span.

Adult↗
PubMed1989

Effects of route of administration of ethanol on high-speed reaction time in young and old rats.

The blood ethanol concentrations (BECs) and reactive capacity of young (8 months) and old (24 months) male Fischer 344 rats were compared at 5, 10, 20, 45, 65, and 90 min following the administration of ethanol (EtOH). The time-dependent effects of intragastric intubation (IG; 3 g/kg) and intraperitoneal injection (IP; 1.5 g/kg) of EtOH (20% w/v) were determined. Subsequent to IG delivery, BECs rose most rapidly within the first 20 min, but did not reach peak levels until 90 min for both young (240 mg/dl) and old rats (250 mg/dl). Following IP injections, BECs escalated within 5 min to 250 mg/dl in the young, to 175 mg/dl in the old, and declined gradually to a stabilized value of 150 mg/dl (young) and 130 mg/dl (old). The old rats never achieved the high BECs seen in the young. Reactive capacity, a measure of auditory/visual reaction time, was inversely related to BECs. As BECs (IP) declined, performance improved at a similar rate in both age groups, although the old rats' performance was more impaired than that of the young. However, BEC per se was not an adequate predictor of reactive capacity. When EtOH was delivered by IG so that BECs remained high for long periods of time, reactive capacity was far less impaired compared with IP delivery in which comparable BECs were present for only a few minutes. The possibility was noted that behavioral tolerance may have developed during the 90-min post-EtOH period, and that the IP delivery method may disrupt behavior in ways independent of brain ethanol levels.

Aging↗
PubMed1989

Effects of ethanol on human fractionated response times.

The effects of ethanol (EtOH) on response components varying along a central vs. peripheral dimension were studied in five subjects. Reaction times (RTs) were fractionated by electromyographical recordings into premotor (central) and motor (peripheral, contractile) components. Highly practiced subjects performed a simple and discrimination RT task and related movement without significant impairment at the moderate blood ethanol concentration (BEC) (0.10%). At the higher BEC (0.17%), all components involving central processing (response time, RT and premotor time) were impaired in both simple and discrimination RT. More peripheral components (contractile time and movement time) were little affected. Contractile time was slowed slightly but significantly, but only in the combination of EtOH and the discrimination task which suggests that the stimulus discrimination stage of information processing can influence the activation of motor units involved in carrying out the movement.

Adult↗
PubMed1988

Reaction time and nigrostriatal dopamine function: the effects of age and practice.

Normal aged and Parkinsonian individuals lose the ability to initiate movements rapidly (increased reaction time) in parallel with changes in the nigrostriatal dopamine (DA) system. However, the ability of these individuals to improve their reaction time with practice has not been adequately assessed. We have developed a rodent model of human reaction time in which reaction time performance correlates highly with neurochemical measures of nigrostriatal DA integrity. In the present report, 15 young and 10 old male Sprague-Dawley rats were conditioned in a reaction time task to release a lever quickly in response to external stimuli in order to avoid a mild footshock. In order to examine the effects of practice on this reaction time task, the young animals were tested for 5 days at 3, 6 and 9 months of age and the old animals were tested for 5 days at 18, 21, and 24 months of age. From this well-practiced task, reaction time response latencies were measured and compared to measures of nigrostriatal DA function (steady-state levels of DA and its metabolites, D2DA receptor affinity and density). The old animals were slower in response latencies than the young animals. These age differences in response latencies, however, disappeared after several days of testing at each of the 3 test sessions, so that the old animals were not significantly slower than the young animals on days 4 and 5 of each session. As expected, the old animals showed reduced striatal D2DA receptor density with no age differences in DA receptor affinity.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1988

Movement initiation characteristics in young adult rats in relation to the high- and low-affinity agonist states of the striatal D2 dopamine receptor.

Changes in the speed of movement initiation as a function of age, brain damage, or rat strain are associated with altered characteristics of nigrostriatal dopamine (DA) neurons and of striatal D2 DA receptors. In the present study we investigated the relationship between movement initiation (response parameters: percent of successful responses and response latency) and the agonist binding states of the D2 DA receptor in corpus striatum in 3-month-old Sprague-Dawley rats (n = 51). In contrast to the typical experimental procedure, the variances of the behavioral and receptor binding data were intentionally made as small as possible to provide the most stringent test of putative relationships among variables. Rats were trained to release a lever as rapidly as possible in response to a light/buzzer (CS) combination in order to avoid a mild footshock (UCS). Percent avoidance scores, latencies of the fastest successful trials (successful latencies) and mean latencies for all responses (mean latencies) were collected for 1000-, 500-, 300- and 200-ms CS-UCS intervals. Twenty-four hours following the last behavioral test, animals were euthanized for measurements of the high- and low-affinity binding of DA to D2 receptors in corpus striatum. The standard errors of the mean for both behavioral and receptor binding parameters were, generally, less than 10%. The tightness of the receptor binding data appeared to be related to a lack of biological variance in the animals rather than to an artifact associated with the behavioral testing procedure, since a parallel experiment indicated that different numbers of behavioral shaping sessions had no effects on striatal D2 binding characteristics.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Apomorphine doses impair the reaction time of fast reacting but not slow reacting rats.

Previously, several studies in our laboratories have linked the ability to initiate movement rapidly (reactive capacity) in several rat strains to markers of nigrostriatal dopamine function. In the present investigation we wished to determine the extent to which fast-reacting (FR) and slow-reacting (SR) rats responded differentially to the effects of dopamine agonist (apomorphine) administration. Fisher 344 rats were operantly conditioned on a shock-avoidance, reactive capacity task which requires extremely fast, ballistic, lever release responses. In FR, but not in SR rats, significant dose-dependent decreases in the per cent of successful avoidance trials were observed in response to apomorphine doses. Moreover, apomorphine brought responding in the FR animals to levels below that of the SR rats. Performance of the SR rats was unaffected by drug treatments. A number of interpretations are consistent with these preliminary data, including the idea that basal differences in speed of reaction and differential responses to a dopamine agonist, antiparkinsonian agent may both be associated with a similar mechanism: differential activation of compartmentalized striatal efferent systems.

Animals↗
PubMed1988

Systematic aerobic exercise and components of reaction time in older women.

Reaction time and its fractionated components were studied in two groups of older women who differ in their level of regular aerobic exercise. Significant group differences were found in all dependent variables indicating that in older women regular aerobic exercise is an important factor influencing the speed of their reactions to simple and discriminatory stimuli, and in the accompanying premotor time, contractile time, and speed of movement following the reaction responses.

Aging↗
PubMed1987

Endurance training effects on striatal D2 dopamine receptor binding and striatal dopamine metabolite levels.

We have previously shown that endurance training is associated with higher binding of [3H]spiperone to striatal D2 dopamine (DA) receptors of presenescent (21 months old) rats. In the present study we investigated the effects of 6 months of endurance training of young adults on the relationship between steady-state levels of DA and its metabolites in striatum and the affinity and density of striatal D2 DA receptors. The extent of training was confirmed by evaluating the maximal oxygen consumption (VO2 max) in the subjects. D2 DA binding was significantly increased at each of 3 [3H]spiperone concentrations in the young runners. A 'synaptic coupling ratio' calculated as the specific DA binding/DOPAC concentration was significantly increased in runners for the 0.1 and 0.4 nM radioligand concentrations. Across experimental groups levels of DA were highly and positively correlated with specific DA binding at the 0.1, 0.2 and 0.4 nM [3H]spiperone concentrations. Together, these results suggest that exercise can alter the number of DA binding sites and the metabolism of DA in young adult animals.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Endurance training effects on striatal D2 dopamine receptor binding and striatal dopamine metabolites in presenescent older rats.

Endurance training is associated with higher binding of 3H-spiperone to striatal D2 dopamine receptors of rats sacrificed 48 h following the last exercise bout (Gilliam et al. 1984). In the present study we investigated the effects of endurance training in presenescent older rats on the relationship between steady-state levels of DA and its metabolites in striatum versus the affinity and density of striatal D2 DA receptors. Citrate synthase activity of the gastrocnemius-plantaris muscle was 29.06 +/- 2.27 mumole/g wet wt in 21-month-old trained rats versus 22.88 +/- 1.13 mumole/g wet wt in 21-month-old untrained animals. DOPAC levels and DOPAC/DA ratios were greater in the old controls. Endurance training was associated with lower DOPAC levels in the 21-month-old animals. Thus, endurance training may postpone selectively changes in DA metabolism over a portion of the lifespan. As expected, the number of D2 DA binding sites was reduced with age (6 months Bmax:429 +/- 21 fmoles/mg protein; 21 months:355 +/- 20) with no change in affinity. The Bmax of old runners was significantly higher (457 +/- 38 fmoles/mg protein) than that of old controls. Thus, endurance training appears to exert a protective effect on D2 dopamine receptors during the lifespan. Taken together, the present results suggest that there may be a possible reciprocal relationship between changes in DA metabolites and DA binding as a function of exercise in presenescent older rats, and that endurance training may decelerate the effects of age both on nigrostriatal dopamine neurons and on striatal D2 dopamine receptors during a portion of the lifespan.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Ethanol and aging effects on movement initiation can be dissociated from general behavioral impairment using a high-speed lever-release task in rats.

An animal model of human reaction time was used to assess the effects of ethanol on reactive capacity (RC) as a function of age. Three doses of ethanol (0.5, 1.0 & 1.5 g/kg of 20% v/v, i.p.) were confirmed by gas chromatographic analysis of blood samples taken immediately following every behavioral test. Fisher 344 rats were trained to use their forepaws to hold down a lever until the onset of a buzzer and light that signalled impending foot shock, which occurred within 200-1000 msec of the stimulus. All rats were shaped to release the lever faster than 200 msec, which permitted them to avoid all shock under saline treatment. In the first experiment, only young adult rats (3-4 mos) were tested. Ethanol caused a dose-dependent impairment of RC. In a second experiment, rats aged 4, 12 and 24 mos were tested. As in previous work, RC was reduced by age. Ethanol caused a dose-dependent impairment of response speed (as indicated by the average of the fastest five RTs) that was exaggerated in the 24 mo-old rats. Ethanol also appeared to amplify the trial-by-trial variability in RC that was typical of the old rats under saline conditions. Nevertheless, if given enough time (1000 msec) most rats (except for a few in the oldest group) were able to avoid shock under ethanol as reliably as under saline conditions, even at the highest dose. Thus, ethanol specifically slowed reaction time while sparing memory and motivational and motor capacities required for success in this task. Both extensive practice and pre-test warm up sessions modified the effects of ethanol; however they did not do so differentially across ages.

Aging↗
PubMed1985

Reactive capacity: a sensitive behavioral marker of movement initiation and nigrostriatal dopamine function.

Thirty-two Long Evans male rats with sham operations or unilateral 6-OHDA-induced damage to meso-telencephalic dopaminergic neurons were evaluated on a reactive capacity task that demanded high speed movement initiation. The task required lever manipulation to avoid signalled shock. The interval between the warning and the shock was incrementally reduced. A one-sleeved vest provided the opportunity to measure movement initiation of each limb independently. Extent of lesion was assessed by [3H]DA uptake, [3H]spiroperidol binding, or DA levels. Movement initiation latencies for each forelimb were found to be linearly related to interhemispheric striatal DA asymmetry induced by microinjections of 6-OHDA. Even those lesions resulting in small to moderate decreases in DA function, including deficits causing no chronic posture or sensory asymmetries, resulted in reactive capacity deficits and greatly slowed reaction time in the paw contralateral to the lesion. Following severe lesions, small yet substantial deficits were also seen in ipsilateral paw performance, which may be related to DA depletions found in the non-lesioned striatum. Thus, a reactive capacity task which requires the animal to react with maximal speed appears to be a potentially good index of nigrostriatal dopamine integrity even when the depletion is not severe.

Animals↗
PubMed1978

Replication of age and physical activity effects on reaction and movement time.

The latency and consistency of simple reaction time, choice reaction time, and movement time of older men who chronically run or participate in racket sports were compared to those of nonactive men of similar age and also to young men of similar characteristics (young runners, young racketsportsmen, and young nonactive men). The findings of Spirduso's (1975) study, of which this investigation was both a replication and an expansion, that older active men physically reacted to stimuli and moved their forearm over a 20 cm distance as quickly as young sedentary men was reported. The older active men were far superior to older sedentary men in all measures. In addition, the older active group was similar to the groups in terms of group homogeneity and within-subject variability, unlike the older nonactive group, who revealed the commonly reported group heterogeneity and within-subject inconsistency.

Adult↗
PubMed1978

Age at menarche and selected menstrual characteristics in athletes at different competitive levels and in different sports.

Ages at menarche in 110 non-athletes, 59 high school atjletes, 53 college athletes, and 18 olympic volleyball candidates were determined through interview. The athletes attained menarche significantly later than the non-athletes (p less than .001), and the olympic athletes attained menarche significantly later than the high school and college athletes (p less than .001). The high school and college athletes did not differ significantly in the mean age at menarche. When menarche in college athletes was analyzed by specific sports, the small samples of participants in golf (n = 4), volleyball (n = 7), swimming (n = 7), basketball (n = 16), and gymnastics and track (n = 6) did not differ significantly from each other in the mean age at menarche. The olympic volleyball aspirants attained menarche significantly later than all sport-specific groups (p less than .05 to p less than .001) except the gymnastics-track and tennis (n = 13) athletes. Smaller samples of non-athletes (n = 27) and college athletes (n = 21 from volleyball and basketball), plus the olympic athletes were also interviewed regarding selected menstrual characteristics. Although the athletes reported a greater incidence of dysmenorrhea and menstrual irregularity, none of the chi square values comparing the three groups was significant.

Adolescent↗
PubMed1976

Voluntary inhibition of the myotatic reflex and premotor response to joint angle displacement.

EMGs from the deltoid muscle of the nonpreferred arm were obtained from 18 subjects (9 males, 9 females). The EMGs resulted from a stretch reflex (reflex latency) from the fall of the relaxed arm from an electromagnet and from the resultant EMGs of a voluntary response to stop the preceived falling arm (premotor response). Ten normal trials were followed by 10 inhibition trials. By conscious relaxation of the arm and inhibition of the deltoid muscle, all subjects on most trials were able to completely eliminate the voluntary premotor responses. Elimination of the myotatic reflex proved much more difficult with two subjects completely inhibiting it on all trials and ten subjects on at least one trial; however when the reflex was not inhibited, the inhibited condition resulted in significantly reduced reflex duration and an increased reflex latency. No sex difference was found in the ability to inhibit the EMG responses.

Adolescent↗
PubMed1975

Reaction and movement time as a function of age and physical activity level.

The SRT, DRT, and MT of older men (OA) who have experienced a life style of chronic physical activity were compared to those of nonactive men of similar age (ONA), and also to active (YA) and nonactive young men (YNA). Although activity level and age were significant factors, most of the activity level-by-age interaction in all but DRT was attributed to the slower performance of the ONAs. At least in this study, a life style of physical activity appeared to play a more dominant role in determining SRT, DRT, and MT than age. The hypothesis that most of the slowing of responses in the aged is attributable to CNS processing rather than MT decrements is repudiated, since MT results paralleled those of SRT and DRT.

Adult↗