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Biomedical subjects

S Tadokoro

Publications and source records attributed to S Tadokoro.

At least 145 records · Page 8Linked to original sources
PubMed1980

Effects of psychotropic drugs on FI responding and adjunctive drinking in rats.

Effects of d-amphetamine (AM), chlorpromazine (CPZ) and diazepam (DZ) on schedule controlled responding (lever-pressing) and adjunctive drinking under a fixed interval (FI) 1.5 min schedule of food reinforcement in rats were investigated. The drinking was measured with a drinkometer and a lickometer. AM 0.13--1.0 mg/kg SC increased the total responses, and decreased the total amount of drinking and licking counts dose-dependently. A marked response increase in the early portion (0.30 sec component of the FI) and mid portion (30--60 sec component), and decrease of the drinking in the mid portion and terminal portion (60--90 sec component) occurred. CPZ 0.25--2.0 mg/kg SC decreased responses, drinking and licking in proportion with the doses. After CPZ, a response decrease in the mid and terminal portions was observed, but not in the early portion. Higher doses of CPZ decreased the drinking and licking in the whole range of the interval. A small dose of DZ (0.25 mg/kg SC) produced a significant response increase. Higher doses of DZ also increased responding, but the change was not significant. The drinking and licking were suppressed by DZ. A dose-related response increase in the mid portion was observed after DZ, but not in the early and terminal portions except after 0.25 mg/kg. Higher doses of DZ (more than 0.5 mg/kg) decreased drinking and licking throughout the whole range of the FI. The present results suggest that the interpellet distribution of responding, drinking and licking, as well as their total values, yield important information when assessing drug effects on FI responding and adjunctive drinking in rats.

Animals↗
PubMed1980

Conditioned drug effects to d-amphetamine- and morphine-induced motor acceleration in mice: experimental approach for placebo effect.

Ninety-two mice were divided into 2 groups and 2.5 mg/kg of d-amphetamine sulfate was given to one group, and 10 mg/kg of morphine hydrochloride to the other, at daily intervals. These two groups were then further divided into flicking light-presented and non-presented groups. The acute effects of the drugs on the ambulatory activity of each mouse were observed for 180 min after the drug administration. The motor-accelerating effect of both drugs was progressively enhanced with repeated administration. After the drugs were administered 10 times, physiological saline was given subcutaneously to the mice and the motor-accelerating effect of the drugs could be observed for a short time, especially in the flicking light-presented groups. This effect disappeared after repeated administration of saline solution at daily intervals for 6 days. Thus, the motor-accelerating effect produced by saline is considered to have been elicited as the result of conditioning between the conditioned stimuli (flicking light and other environmental factors) and drug effects.

Animals↗
PubMed1979

[Individual differences in the accelerating effect of methamphetamine, d-amphetamine and morphine on ambulatory activity in mice (author's transl)].

Several problems concerning the ambulatory activity were discussed from the viewpoint of drug assay using about 700 adult male mice of ddG strain. Each response pattern for 180 approximately 400 min obtained from the temporal changes of ambulatory activity after administration of methamphetamine (1 approximately 16 mg/kg s.c.), d-amphetamine (1.25 approximately 5 mg/kg s.c.) or morphine (5 approximately 20 mg/kg s.c.) was recorded and used for the data analysis. All the above mentioned drugs markedly accelerated the activity when the doses were optimal. However, the individual response to the drugs sometimes reached a 40- approximately 70-fold difference, even though both animal and measurement conditions were fixed as constant way as possible. The time when the experiments took place did not explain the individual differences, nor did the season or body weight of the animal. However, there was the possibility of colony differences. Animals with relatively high activity prior to drug administration tended to respond more forcibly after administration of the drugs. It was found from the statistical investigation that constant observation of over 1 hr using at least 15 animals was required in order to determine a standard effect of the drug. Furthermore, the accelerating effect of methamphetamine and d-amphetamine on the activity was observed to be dose-dependent when below 4 and 5 mg/kg was given, respectively. On the contrary, the effect decreased dose-dependently when higher doses were given as stereotyped behavior such as head-swaying, continuous sniffing and circular movements in opposition to the horizontal movements also developed dose-dependently. As the qualitatively different behavior could be simultaneously measured, the individual differences were more apparent.

Amphetamines↗
PubMed1978

Automatic measurement of drinking in rats: effects of hypophysectomy.

A new apparatus for the continuous measurement of drinking in the rats was assembled. The principle of the device is as follows: a cartridge which makes water drops (0.05 ml) is inserted between a water tank and a drinking spout. When a rat drinks, water falls into the cartridge drop by drop and the number of drops is electrically counted. The total count of drops per day, as well as counts at definite intervals, can be atuomatically printed out. To test apparatus reliability and applicability, drinking behavior in hypophysectomized rats was investigated in the light and dark phases, alternating every 12 hr. Activity and feeding in these phases were also observed. In the sham-operated rats, the total daily water intake was 30-40 ml, which corresponded to 10-15% of the body weight, and 85-95% of the total daily drinking counts were recorded in the dark phase. In the hypophysectomized rats, a large amount of water was drunk immediately after the operation. However, the high rate of drinking rapidly returned to near the normal level within a few days. Drinking in the dark phase decreased to about 75% of the total daily, but synchronization with the light-dark cycle was still maintained. The daily patterns of activity and eating ran nearly parallel with the drinking behavior. These results indicate that our drinkometer could have extensive applications within many fields of research.

Animals↗
PubMed1978

[Simple and easy method for measurement of ambulatory activity in mice (author's transl)].

A hand-made apparatus which is easily manipulative, cheap, durable and clean was used to measure ambulatory activity of a mouse. The apparatus was assembled with the same type of two plastic round basins commercially available (25 cm in diameter) put one upon another. A pivot was fixed at the center of the outsurface of the inner basin (A), and its open end was inserted into the open socket fixed at the center on the bottom of the outer basin (B). Three microswitches equipped on the brim of (B) at equal intervals were activated and the counts were recorded according to the tiltings of (A) through the movements of the mouse. In order to examine accuracy of the measurement, effects of d-amphetamine (1.25 approximately 5.0 mg/kg), methamphetamine (1.0 approximately 4.0 mg/kg), cocaine (10 approximately 40 mg/kg) and morphine (5.0 approximately 20.0 mg/kg) on the ambulatory activity were investigated. Marked accelerating effects were observed dose dependently after the administrations of all the drugs. Furthermore, the patterns of the activity showed characteristic properties of each drug. This method is especially useful to measure the acute effect of drugs on the ambulatory activity in mice, and many units can be set up at the same time.

Amphetamines↗
PubMed1976

Cumulative effects of penfluridol, a long-acting neuroleptic drug, as assayed by its behavioral actions.

Penfluridol, a long-acting neuroleptic drug, was repeatedly given to rats well trained on the discriminated avoidance schedule (intertrial interval, 25 sec; warning duration, 5 sec), and accumulation of the effects were investigated by observing the behavioral changes. When penfluridol was orally given in a dose of 2-8 mg/kg once daily for 10 consecutive days, the suppression of avoidance response was progressively enhanced until the 3rd-4th day. But from the 4th day, the maximum level of suppression was maintained during the later medication. On its withdrawal, the avoidance response was gradually restored, returning to the initial level in 3-4 days. When 8 mg/kg was given at 1-2 weeks after the withdrawal, the same suppression was observed as after the single administration of the same dose. The progressive enhancement of suppression in the early half of the medication period evidently indicated the cumulative effect. The degree of suppression during the plateau showed a linear correlation with the dosage, and was estimated to be about 3,5 times as high as in the corresponding single administration.

Animals↗
PubMed1976

Rat strain differences in the acquisition of conditioned avoidance responses and in the effects of diazepam.

Adult male albino rats of three strains--Wistar, Sprague-Dawley and Holtzman--were trained to press a lever to avoid electric shocks under Sidman-type (R-S interval-20 sec; S-S interval=5 sec) and discriminated avoidance (ITI-15 sec; warning duration=5 sec) schedules, and the acquisition processes of avoidance responses, and the properties of behavioral baselines were investigated. Under both schedules, Wistar strain rats, though showing poorer results than the other two in the beginning, rapidly progressed with the repetitive training, and finally displayed excellent and stable performances. Srague-Dawley strain rats were poorer in performances, with delayed acquisition and prolonged warm-up effect in the within-session performance. The results of Holtzman strain rats ranked between the two. After the establishment of stable behavioral baselines under both schedules, 0.5, 1.0 and 2.0 mg/kg of diazepam were given subcutaneously, and it was found that in Wistar and Holtzman strain rats, the avoidance responses were inhibited together with increase of delivered shocks in parallel to the doses. In Sprague-Dawley strain rats, however, the avoidance responses were conversely improved with 0.5 and 1.0 mg/kg, while such tended to be inhibited with 2.0 mg/kg, with marked concomitant ataxia. As definite strain differences in avoidance response were demonstrated herein, selection of the most appropriate strain should be made when designing behavioral experiments.

Animals↗