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B Jänicke

Publications and source records attributed to B Jänicke.

12 recordsLinked to original sources
PubMed1994

The effects of prenatal exposure to hypoxia on the behavior of rats during their life span.

The aim of this study was to investigate the influence of moderate prenatal damage on adaptability during the juvenile, adult, and senile phases. Pregnant rats were exposed to a 12% normobaric hypoxia from day 1 to 17 postconception. Pregnancy was normal in both the treated animals and the controls. Erythrocytes, hemoglobin, and hematocrit did not increase in the treated pregnant animals. During the first 3 weeks, the F1 generation showed developmental deviations in physiological characteristics. Throughout subsequent ontogeny, motor performance, cognitive ability, and adaptability to physical stress were determined with a test battery of varying demands. Some of the differences (e.g., locomotor activity, learning ability) between juvenile untreated and treated rats disappeared during the adult phase. Motor and coordinative abilities, however, remained partially impaired in the old rats, especially under high demands. This study, and previous findings with alcohol (37), indicate that prenatal exposure to a noxa may result in a highly differentiated brain injury pattern. Depending on the different functions, damage may intensify age-dependent adaptive disorders or provoke impairment without influencing the course of development.

Adaptation, Physiological↗
PubMed1993

The effects of prenatal alcohol exposure on the behavior of rats during their life span.

Ontogenesis is closely related to the ability to adapt to endogenous and exogenous stimuli. However, this precondition for viability does not remain stable; it changes in correlation to the phases of life. In this long-term study with rats, the extent to which moderate prenatal damage influences the adaptability in the juvenile, adult and senile phases was examined. For this purpose rat fetuses were exposed to alcohol (6 g/kg bw/day) by treating the pregnant rats via drinking water from gestation days 7 to 17. In the juvenile phase (0-3 months), no substantial differences in comparison to controls were recorded. Exceptions were a delayed development in the negative geotaxis (posture reflex) and a transiently higher exploratory activity in the open field test. In the adult phase (> 3-27 months), reduced performance was observed in basic functions such as body temperature regulation. Additionally, diminished performance was seen in response to high demands in motor-coordination (rotorod). During the senile phase (> 27 months), impairment of nearly all tested functions occurred earlier and was more pronounced.

Adaptation, Physiological↗
PubMed1991

Effects of age and drugs on food and fluid intake.

In young adults rats (5-month-old) d-amphetamine (2 mg/kg/d), administered on a long-term basis via drinking water, caused a moderate reduction in the intake of nutriments, which in part normalized within three weeks. Self-administration of a daily dose of 20 mg per kg diazepam over a period of 26 days led neither to hypodipsia nor to anorexia. Pentylenetetrazol (70 mg/kg/d) primarily produced a hypodipsia. The three drugs did not influence body weight. In 27-month-old rats d-amphetamine and pentylenetetrazol had the same qualitative effects. Intake of nutriments and the development of body weight were influenced more strongly than in young rats. Diazepam also had a marked effect in old animals. Nootropics (piracetam, pyrithinol, hydergin, centrophenoxin, aniracetam) had no effects on the parameters observed. When the agents were given in combination in both age groups the nootropic piracetam (230 mg/kg/d) weakened the effects induced by d-amphetamine, pentylenetetrazol or diazepam alone. The benzodiazepine, however, enhanced the loss of body weight and fluid intake in old rats caused by the stimulant or analeptic, whereas food intake remained unaffected. The results support the hypothesis that an organism's adaptivity to external and internal stimuli is reduced in later life. The behavior of young and old rats in the open field was not affected by any drug medication.

Aging↗
PubMed1990

Learning abilities of rats in multiple T-mazes of two degrees of complexity under the influence of d-amphetamine.

The effect of d-amphetamine on the learning capacity of male Wistar rats was investigated in multiple T-mazes in two experiments of increasing or decreasing degree of difficulty. Running speed, distance covered and the number of errors were scored to indicate proficiency and success of learning. These parameters, as well as the distribution of errors (goal-directed orientation), correction of errors (situational orientation) and latency at the decision points (discrimination time) were considered to represent cognitive components. The results demonstrated an experiment effect in that the rats showed more difficulty in learning, as exhibited by a slower running speed and more errors, in the maze with successively increasing demands than in the one with decreasing demands. Oral self-administered d-amphetamine in a dosage of 3-4 mg/kg/day or 7-8 mg/kg/day significantly increased the running speed in a dose-dependent manner. By contrast, success of learning and goal-directed orientation decreased. Situational orientation was, however, dose-dependently improved, at least in the experiment with the increasing demand.

Animals↗
PubMed1989

P-hydroxy-norephedrine as a possible mediator causing the reduction of oral intake of D-amphetamine in rats.

In rats D-amphetamine is predominantly metabolized by hydroxylation to p-hydroxy-norephedrine (p-HNE); in guinea pigs, however, by deamination to benzoic acid. After 2-3 days on dosages of 1 mg/kg per day and more rats begin to reduce their oral intake of the stimulant whereas guinea pigs do not. In the present study we examined the hypothesis that the formation of p-HNE in the CNS is partially responsible for this aversion. To determine the elimination of D-amphetamine and the increase in p-HNE, groups of male Wistar rats were given various doses (0.5-5 mg/kg per day) of D-amphetamine in their drinking water intragastrically and intravenously. D-Amphetamine in the brain was determined by radioimmunoassay, p-HNE by high performance liquid chromatography followed by electrochemical detection. In contrast to the concentration of D-amphetamine, the p-HNE-content is independent of the route of administration; after oral treatment it showed a linear increase. The results reveal that p-HNE induces the aversion to the stimulant and that the ratio of D-amphetamine to its metabolite determines the onset of this aversion. No p-HNE was found in the brain of guinea pigs. Guinea pigs do not show any aversion to drinking D-amphetamine solutions, even in high dosages.

Administration, Oral↗
PubMed1988

The influence of brain catecholamines on 'drug taking behaviour' relative to oral self-administration of d-amphetamine by rats.

Oral administration of 5 mg/kg of d-amphetamine to adult Wistar rats caused brain NE to decrease to approx. 80% of the control level during 4-24 h after acute treatment and slowly further to 65% after 24 days of self-administration via drinking water. The norepinephrine (NE)-reducing effect was first recognized at 1 mg/kg and appeared to peak at 5 mg/kg of d-amphetamine. Brain dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were only shortly affected. Neither iprindole nor desipramine altered the effect of amphetamine on brain NE. DA was decreased by both inhibitors depending on the duration of pre-treatment. Iproniazid and alpha-methyl-p-tyrosine antagonized and potentiated respectively the amphetamine effect on NE- and DA-concentration after 4 days of simultaneous treatment. In the free choice experiment (water vs. 0.005% d-amphetamine solution) rats developed an aversion to amphetamine. The number of rats taking the drug and the consumption by rats still drinking it declined gradually from 100% and approx. 3 mg/kg/day to 50% and approx. 1.5 mg/kg/day, respectively, during 18 days. The time course of the developing aversive reaction to oral amphetamine ran approximately parallel to that of NE-depletion. Iprindole and desipramine intensified, iproniazid and propranolol weakened, while alpha-methyl-p-tyrosine and haloperidol hardly influenced the aversive effect of amphetamine. It is concluded that the development of aversive behaviour in response to oral d-amphetamine is mediated not only through the depleting effect of amphetamine on NE stores but also by its direct stimulation at beta-adrenergic receptors in the CNS.

Administration, Oral↗
PubMed1986

Motor activity of different-aged Cercopithecidae: silvered-leaf monkey (Presbytis cristatus Esch.), lion-tailed monkey (Macaca silenus L.), moor macaque (Macaca maura Cuv.) as observed in the Zoological Garden, Berlin (West).

The activity of different-aged monkeys belonging to three species of Cercopithecidae was quantitatively analyzed in a 1 1/2-year study. The species, silvered-leaf monkey (Presbytis cristatus Esch.), lion-tailed monkey (Macaca silenus L.) and moor macaque (Macaca maura Cuv.) were observed in the Zoological Garden, Berlin (West). The data of a combined cross-sectional analysis across all three species indicate that the course of age-related changes in the frequency of movement can be depicted as graduated and differentiated. These results are discussed in terms of a reverse development pattern in old age compared to that of early youth.

Aging↗
PubMed1984

Changes in motor activity with age and the effects of pharmacologic treatment.

In a previous study the decline in the motor performance of old rats was determined to be differential. In this study, whether, and to what extent, this decline can be pharmacologically influenced was tested. Therefore, 27 month old rats were orally treated with several nootropics and d-amphetamine for six weeks. Food and water intake were determined. The rats were tested on spontaneous activity and on the tilting plane, climbing, and rotarod tests. The results showed that the nootropics only effected pronounced improvements on complex motor tasks such as on the rotarod test. In contrast, amphetamine treatment caused rather negative effects. This could be observed in the motor performance as well as in the food and water intake. Young rats did not have this sort of reaction to amphetamine. The nootropics were all well tolerated. Additionally, it was obvious that the untreated rats also showed a slight improvement in motor performance due to repeated practice.

Aging↗
PubMed1983

Motor performance achievements in rats of different ages.

Motor performance of rats of different ages was determined in a cross sectional study. The design includes a test battery of seven motor tasks of graduated complexity. The results show a hierarchical order of impairments of motor functions in aging rats; that is, the more complex the task requirement, the earlier and more pronounced is the susceptibility to deterioration of motor coordination. In spontaneous activity and swimming no difference could be observed between young and old rats. With increasing requirements for the tilting-plane, horizontal wire, climbing and chimney tests as well as the rotarod test, the older rats show a differentiated decrease in performance. The findings are discussed in respect to the theory that aging is a reverse process of early development.

Aging↗
PubMedDate not supplied

Effects of chronic hypoxia on behavioral and physiological parameters.

Aging is a process accompanied by progressive susceptibility to disturbances and impairments in adaptability. The influence of age on the capacity to adapt to chronic normobaric hypoxia (10%) was studied in 4, 20 and 27 month old rats. Adaptation was measured for four days by food and fluid intake and spontaneous activity. In addition the values of the pO2, pCO2, pH-value, Na+ concentration and hematocrit were determined. The results show an initial marked decline for the three modalities of behavior in all age groups. While age-dependent differences were exhibited, for the adaptation course in nourishment and spontaneous activity, the values of the blood gases and hematocrit did not reveal age-related changes. Thus, physiological parameters and behavior are not consistent regarding the effects of age on adaptation capacity.

Adaptation, Physiological↗
PubMedDate not supplied

Influence of normobaric hypoxia on learning capacity of different aged rats.

In this study it was tested to what extent subchronic normobaric hypoxia (10% oxygen by volume) influences the learning performance of rats of different ages (4, 20, 30 months). The animals were presented with two successive conditioning patterns (FR 10/DRL). After acquisition of the FR 10 under normoxic conditions in a Skinner box the rats needed to reestablish the learned behavior under normoxia and further under hypoxia. Following this, the rats had to learn the DRL in a test chamber under the conditions of reduced oxygen. Their performance was compared with that of control animals which had to accomplish the tasks under normoxia. No age differences were observed under normoxia in learning the FR 10. However, the reestablishment of FR 10 under hypoxic conditions was less well performed by old rats than younger ones. The young rats (4 months) had a high efficiency level on the DRL-schedule under normoxia which was not impaired by hypoxia. The old rats (30 months) had considerably lower performance level under normoxia which was not further reduced in individuals by hypoxia. The performance of the middle group (20 months) was, under normoxia, at an intermediate level, while oxygen reduction led to a pronounced reduction in efficiency.

Adaptation, Physiological↗