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Biomedical subjects

R G Burright

Publications and source records attributed to R G Burright.

At least 37 records · Page 2Linked to original sources
PubMed1987

The consequences of parasitic infection for the behavior of the mammalian host.

As many as one billion people may be infected with animal parasites. The behavioral consequences of such infection, or of illness in general, is poorly understood. This issue is discussed using as an example infection of mice with Toxocara canis, the common roundworm of dogs. Current literature suggests that two-thirds of all dogs have been infected with this parasite, and 7% of all humans have antibodies to T. canis. T. canis completes its life cycle in dogs, but when it infects aberrant mammalian hosts (e.g., humans or mice), larvae migrate through various organ systems including the brain, where they can remain viable and mobile for extended periods of time. Changes in motor activity, sensory reactivity, and learning of mice infected with T. canis have been observed. The pattern of behavioral changes is influenced by the infection regime and exposure to other toxicants such as lead.

Animals↗
PubMed1986

The effects of verapamil and ethanol on body temperature and motor coordination.

Male, adult mice of the Binghamton heterogeneous stock received one of two doses of ethanol (1.0 g/kg or 2.0 g/kg in saline) alone or in combination with the calcium (Ca2+) slow channel blocker, verapamil (5.45 mg/kg in 25% v/v ethanol in saline). Hypothermic responses and motor incoordination were assessed in terms of rectal temperatures and rotorod activity both 20 and 60 min after drug administration. Verapamil alone did not affect body temperature, but it potentiated ethanol-induced hypothermia at both post-administration test times. Both verapamil and ethanol impaired muscular coordination and these effects were additive at the two observation periods. Verapamil did not affect ethanol blood levels from 10 to 80 min after administration of the drugs. Since motor impairment was observed when verapamil was administered with only its ethanol vehicle, this suggests a powerful interactive effect between the two drugs.

Animals↗
PubMed1986

Lead, age and aggression in male mice.

The impact of eleven weeks of ingestion of a 0.5% lead acetate solution on agonistic behavior of male Binghamton Heterogeneous stock mice (either 120 or 660 days of age) was examined. Similar aged mice were paired for aggression testing. Not surprisingly, younger mice, regardless of fluid history fought more vigorously than older mice. However, when mice of similar fluid history were paired together, lead ingestion decreased the latency to fight only in older mice. Regardless of their prior fighting history, when lead treated mice fought similar aged controls, the lead exposed mice in younger pairs were typically subordinate; but in older pairs, lead exposed mice were dominant. These results, coupled with extant literature concerning age-related changes in endocrine function, pituitary-adrenal activity, and lead-induced changes in hippocampal function suggest that future work directed at mechanism(s) underlying lead-induced alterations in agonistic behavior should consider life span changes in biobehavioral profiles.

Age Factors↗
PubMed1986

Short term lead exposure, age and food deprivation: interactive effects on wheel running behavior of adult male mice.

In three separate experiments, young-adult (75 days old) intermediate-age (220 days old), or older (365 days old) Binghamton Heterogeneous Stock (HET) male mice were maintained on food and either water or a 0.5% lead-acetate drinking solution for only three weeks prior to placement in cages with attached running wheels. Mice were kept on their assigned sources of fluid while in these wheeled cages for six days. On Days 3 and 4 of their 6-day access to the running wheels all mice were deprived of food, but the appropriate drinking fluid remained available continually. Even with this relatively low level of dietary lead exposure, which occurred only during adulthood and immediately prior to (and continued during) the 6-day measurement period, the 48-hour food deprivation challenge differentially altered the wheel running of lead-exposed and control mice; but those effects were apparently altered by the age of the adult mice used in each of the three experiments. These data are discussed in terms of the potency of environmental challenges in revealing behavioral changes related to age and even short-term exposure to environmental/dietary toxicants during adulthood.

Aging↗
PubMed1985

The progression of behavioral and pathological effects of the parasite Toxocara canis in the mouse.

Toxocara canis, the parasitic roundworm of the dog may infect aberrant hosts including mice and humans. The present study examined the behavioral and pathological changes at each of three postintubation periods (Period 1: 8-10 days, 2: 49-51 days, and 3: 84-86 days postintubation, respectively) in independent groups of mice intubated with 1000 eggs of T. canis. Eight-ten days after intubation Toxocara infected animals typically showed depressed levels of activity relative to saline-intubated controls. The scope and severity of behavioral changes were attenuated when different mice were tested 49-51 days after infection, and then became more severe when the third set of animals was tested 84-86 days after intubation. While brain pathology increased over the three periods, visceral organs showed marked pathology 8-10 days after intubation followed by a decrease in severity. These data suggest that Toxocara associated pathological changes in visceral organs and in the brain have behavioral consequences in mice. Given the similarity in migratory pathways of this parasite in rodents and humans, and the findings of T. canis larvae in human brain tissue, the results of this animal study may have implications concerning the possible etiology of behavioral disorders for children who have a known history of pica for dirt.

Animals↗
PubMed1985

Behavioral effects of early lead exposure and subsequent toxocariasis in mice.

Mice were maintained under standard conditions, or treated with lead from birth, until they were approximately 40 d of age. At that time the lead solution was replaced with tap water and all animals were gastrointestinally intubated with either the parasite Toxocara canis or normal saline. At 2-5 wk following intubation the behavioral effects of T. canis in combination with the prior history of lead ingestion were compared to those produced by administration of either T. canis or lead alone or a single saline intubation. Differential group activity scores (cage crosses and standups) in response to changes in the home-cage environment during testing sessions were observed. While the addition of a second tier to the home cage during testing resulted in increased activity scores for all groups, changing the home-cage bedding produced increased activity only in the T. canis alone or prior lead ingestion alone groups. However, there were no differences in the number of parasite larvae found in fresh brain tissue preparations in either the T. canis alone or T. canis plus lead-history combination groups.

Animals↗
PubMed1984

Behavioral analysis of kanamycin administration to mice.

The present series of experiments investigated behavioral changes in HET mice following administration of kanamycin, one of the aminoglycoside antibiotics. After drug treatment, HET mice showed changes in complex behaviors, including male agonistic behavior, female postpartum aggression, and tactile discrimination performance. Specifically, the temporal distribution of agonistic behavior appears to be affected by kanamycin treatment in both males and females, and kanamycin administration seems to alter reversal performance on a tactile discrimination task. These findings suggest the need for more careful examination of behaviors which may prove to be sensitive indices of antibiotic toxicity.

Aggression↗
PubMed1983

Lead exposure and agonistic behavior of adult mice of two ages.

Adult male Heterogeneous stock (HET) mice were exposed to a 0.5% lead acetate solution when they were either 65 or 330 days of age. Fifteen weeks later they were paired with same age (young or old) water control HET mice and tested for aggression. All pairs of younger mice fought and six out of eleven pairs of older mice exhibited agonistic behavior. Although not all pairs of mice which fought achieved dominance, when dominant/subordinate relationships were established, the younger adults exposed to lead typically were subordinate. In contrast, older adults exposed to lead were always dominant. Differences in agonistic behavior patterns also were noted, with younger adults displaying more frequent and longer bouts of fighting than the older mice.

Aggression↗
PubMed1983

Behavioral changes in mice following lead administration during several stages of development.

How lead ingestion during different developmental periods influences activity of mice was investigated. Binghamton Heterogenous Stock (HET) mice were assigned to one of four groups defined by a 2 X 2 factorial in which the only available drinking fluid was either lead (L) or water (C) from the time of mating to birth or from birth to the end of the experiment. Thus, a control group (CC) received water throughout, whereas the other three groups received a 0.5% lead acetate solution at the time they were mated (LC) or when pups were discovered (group CL), or throughout the experiment (group LL). The effects of these exposure regimes on activity were assessed in an open field or a running wheel when the mice were 25 days of age and then again when they were 55 days old. Aspects of agonistic behavior were also examined in these animals. Mice that received lead only following birth (CL group) appeared most affected in the open field and in running wheels. But, both the direction and degree of this effect were influenced by the specific test situation and measures as well as by the age of the mouse when tested. For example, the CL group crossed the most squares in the open field at both ages. However, the CL group was less active during their first day in the running wheels when 25 days old, but not when 55 days old. In general, activity of the LC group was least affected by administration of lead, but the effects of continued exposure to this toxic substance (LL group) were not simply additive. In contrast to measures of activity, agonistic testing at 60 days of age showed that all groups that had been or were being exposed to lead (CL, LC, LL) displayed a shorter latency to fight when compared to the control group (CC).

Age Factors↗
PubMed1983

Neuropathological studies of experimental toxocariasis in lead exposed mice.

Binghamton Heterogeneous stock mice intubated with embryonated eggs from the common parasite of dogs, Toxocara canis, display dramatic alterations in behavior. Many of these behavioral changes are markedly attenuated if mice are maintained also on a drinking solution containing lead acetate. The data presented here, however, show that the extensive neural degeneration of the CNS occurs after T. canis infection and that the nature and extent of this degeneration is similar, regardless of whether mice had been administered parasites alone or in combination with lead. Thus the neuropathological data reported in detail here cannot account for the striking interactive influence of T. canis and lead on behavior.

Animals↗
PubMed1983

A multivariate approach to the analysis of genetic and septal lesion effects on maze performance in mice.

Reported are univariate and multivariate analyses concerning spatial discrimination behavior of Binghamton heterogeneous (HET) stock, C57BL/6J, and RF/J mice that had received either septal lesions or control surgery. In acquisition of an appetitively motivated T-maze task, lesions impaired HET but improved RF performance relative to their respective controls. When mice with lesions were reversed on a spatial discrimination acquired in a 17 degrees C water maze their performance was worse than control animals; the magnitude of the deficit was strain-specific. Measures of reactivity to handling suggested that HET and RF mice with lesions were more reactive than their control counterparts, while there was no such difference in C57 mice. Multivariate approaches broadly corroborated the importance of many complex Gene X Environment interactions that mold experience and thus behavior. In addition, they appeared to give some potentially important insights into the differential "behavioral profiles" of mice with lesions and control mice of the three genotypes; for instance, reactivity to handling and repeated error measurements were important variables in discriminating among the various groups in both learning tasks. The need to establish better and more stable behavioral profiles is clear; thus, multivariate techniques should be considered as useful, additional tools for the development and evaluation of explanatory theories regarding functions of central nervous system regions.

Animals↗
PubMed1983

Attenuation of reversal deficits of mice with septal lesions by shifts in the motivational context.

Response perseveration following septal lesions, demonstrated on tasks that require change of a learned pattern of responding, depends in part on a relatively constant motivational context. The present experiment examined the effects of concurrent changes in the temperature of the water in a water-escape maze and the reversal of a spatial discrimination in mice that had received either septal lesions or control surgery. Control and experimental mice were trained on a spatial discrimination in either 17 or 34 degrees C water. Following acquisition, reversal training was conducted in the maze filled with the same-temperature water used during acquisition or water temperature as well as spatial reinforcement contingencies were reversed. When the water temperature remained constant across acquisition and reversal, the mice with septal lesions showed persistence during reversal training. Changing the water temperature concurrently with the institution of reversal training attenuated the perseverative deficits of mice with lesions, in contrast to the relative lack of effect in control animals. These results are discussed within the framework of the role that the septal region plays in attention.

Animals↗
PubMed1982

Influence of environmental rearing history and postsurgical environmental change on the septal rage syndrome in mice.

Reactivity to handling was examined in Binghamton Heterogeneous (HET) mice given septal lesions or control surgery following 5 weeks of postweaning rearing in enriched or restricted environments. Three housing conditions were employed: continuous enrichment, continuous restriction (both pre- and postsurgically), and a group switched from environmental enrichment to restriction 24 hours after surgery. The restricted mice were more reactive to handling than the enriched mice presurgically (60 days old), and interactions of housing conditions and surgery were found over the seven day postsurgical handling and testing period. The restricted mice given septal lesions greatly increased in reactivity postsurgically, while the intact controls declined in reactivity over the postsurgical week. The enriched septals were only moderately increased over the low presurgical reactivity baseline, and were much less reactive than the restricted septals. Perhaps the most remarkable finding was the dramatic and immediate increase in reactivity in the septals switched from enrichment to restriction, while intact controls showed no effect of the switch. These results emphasize the importance of experience in determining the effects of septal damage, and may be useful in examining other correlates of septal rage.

Analysis of Variance↗
PubMed1982

Effect of amphetamine and cocaine on seizure in lead treated mice.

Mice, genetically selected for differences in brain weight were employed. Lead administration (0.5% lead acetate) from conception increased the proportion of 21 day old mice exhibiting seizures; total duration of observed seizures was also increased. Mice from the low brain weight line more frequently exhibited seizures than either mice from the high brain weight line or the Binghamton heterogeneous stock. Although genome and lead administration after bodyweight, the inability of bodyweight to predict seizure occurrence and/or total duration of seizure within conditions also was noted. Lead administration from conception through testing increased the probability and duration of transcorneally induced electroconvulsive seizures of 21 day old mice within all three genotypes, and both cocaine and amphetamine injections 15 min prior to ECS reduced the number of animals exhibiting seizures as well as the duration of seizures in both lead treated and control mice.

Animals↗
PubMed1982

The effects of dietary fat and lead ingestion on blood lead levels in mice.

To examine the effects of dietary fat on the levels of lead in the blood, 34-40-d-old male mice were fed normal or high-fat diets along with distilled water for an initial 48-h exposure period. Following this session, subjects from each diet condition were administered either 0, 0.075, or 0.5% lead acetate through the drinking water during the next 48 h along with their respective diets. Atomic absorption was used to analyze blood-lead levels. At each concentration of lead, the high-fat diet increased the blood lead content over subjects fed the control diet. The highest blood lead levels were found in the 0.5% lead acetate, high-fat diet condition. The importance of nutritional considerations in understanding lead toxicity is discussed.

Animals↗