Effects Of Magnesium Pemoline Research Articles

Effects of magnesium pemoline on a delayed match-to-sample task in monkeys

The effects of magnesium pemoline on retention were examined in monkeys ( Cebus apella ) previously trained in a delayed match-to-sample paradigm, in order to distinguish between drug effects on learning and retention. Three monkeys were dosed orally at 0.25, 1, 2, 4, and 16 mg/kg with magnesium pemoline and tested at three fixed delays (2 sec, 60 sec, and 180 or 300 sec). The results showed no effect on retention of the sample although the data suggested that magnesium pemoline interferes with previously stable retention of the sample at the short delay (2 sec).

Effects of magnesium pemoline on the habituation of an innate fear response in Carassius auratus

After an initial adaptation period in a tall, narrow tank, goldfish typically swim up and down at a fairly constant rate. If a loud buzzer is sounded during the ascent, a fish will either become immobile and remain near or actively swim to the bottom of the tank. Upon repeated experience with the buzzer, this apparently innate response habituates and the ascending latency gradually approaches baseline. This innate response was enhanced by a 10 mg/kg ip injection of magnesium pemoline. While the amount of habituation was greater in the experimental drug group than either the drug or buzzer control, this was apparently due to the initially higher response level. Neither spontaneous activity nor total testing time differed reliably among the three groups.

Separation of the effects of magnesium pemoline on avoidance learning and memory from its central nervous system stimulant properties by chlordiazepoxide.

SummaryMagnesium pemoline (20 mg/kg, ip) was found to enhance the acquisition and retention of a double-T maze in male Swiss-Webster mice when administered 25 min prior to training or from 1 to 180 min posttrial. The general stimulant action of magnesium pemoline was completely abolished by pretreatment with chlordiazepoxide (15 mg/kg, sc), although the mice still showed enhanced memory of the avoidance task. These data suggest that the nonspecific arousal associated with magnesium pemoline is not responsible for the demonstrated effects upon avoidance learning and memory.

Effect of magnesium pemoline on the aversive threshold to shock in the rat.

The effect of magnesium pemoline on pain thresholds in 52 rats was tested via the jump-flinch technique in groups receiving 0, 5, 10, or 20 mg/kg of the drug. No significant differences were found between groups in the number of jumps or the specific mean intensity at which the first jump was displayed over 4 series of 17 different shock intensities. The findings were interpreted as refuting the hypothesis that superior performance of drug-treated Ss in avoidance situations is due to a sensitization effect to electric shock brought about by drug action.

Effects of Magnesium Pemoline in Dimethylsulfoxide on Reversal Learning, Motor Activity, and Water Intake

52 rats were given reversal training in a T-maze under magnesium pemoline either dissolved in dimethylsulfoxide (DMSO) or suspended in gum tragacanth. The course of reversal learning was unaltered as a consequence of drug administration except for the deleterious performance of the magnesium pemoline in DMSO animals on the 10th reversal. Regardless of vehicle, magnesium pemoline enhanced motor activity in an L-maze. While both magnesium pemoline groups exhibited reduced water consumption relative to controls, both DMSO groups exhibited an increase, concurrent with reduced body weight. It is suggested that DMSO is not an inert placebo and should be used with caution in repeated-administration behavioral studies.

The effect of magnesium pemoline on discrimination learning and exploratory behavior

A drug group was injected interperitoneally with 10mg/kg body weight of magnesium pemoline in tragacanth and a control group received the vehicle substance only. The animals were tested on a two-alternative forced choice brightness discrimination task and an open-field test of exploratory behavior. The drug group (1) increased exploratory behavior; (2) produced superior percentage correct discrimination performance; and (3) decreased running speed. The results indicated that the drug, besides having considerable stimulant properties, enhanced learning. Also, a previous study on magnesium pemoline and discrimination learning was reanalyzed and superior discrimination was found for the drug group.

The effect of magnesium pemoline, tricyanoaminopropene, and d-amphetamine on discriminated avoidance performance in rats as a function of age

The effects of magnesium pemoline, tricyanoaminopropene, and d-amphetamine on the acquisition of a discriminated avoidance response were compared in 30-, 50-, and 100-day-old naive rats. The rats were placed in an automated shuttlebox immediately after drug treatment. The number of avoidance responses in a series of 100 trials was measured. Ten days after the initial acquisition session, the rats were retrained on the same task. The 30-day group was inferior to the 50- and 100-day groups in the training session, but no differences occurred in retraining. The drug-treated groups showed improved performance in the initial training session but were not different from the controls in the retraining session. No Drug by Age interaction was significant.

Effects of stimulant drugs on maze swimming.

After learning to swim a water maze during magnesium pemoline treatment, albino rats recovered from drug withdrawal before beginning a series of retention, transfer and relearning tests. Time and error scores showed clearly that the drug enhanced original learning, perhaps by reducing the delay of escape. In a further experiment, escape time was controlled during original learning in groups receiving magnesium pemoline, amphetamine or pentylenetetrazol, and no drug enhancement of learning appeared in retention or transfer tests. However, active pentylenetetrazol reduced errors during relearning, contrary to the effect of magnesium pemoline.

The effects of magnesium pemoline, caffeine and picrotoxin on a food reinforced discrimination task

The effects of several doses of magnesium pemoline, caffeine, and picrotoxin on the acquisition of a food-reinforced light-dark discrimination task in the T-maze were compared. Both magnesium pemoline and caffeine facilitated the acquisition of the task at appropriate doses. The picrotoxin-treated animals were incapacitated except at the lowest dose administered.

The effects of magnesium pemoline upon repeated acquisition and extinction of a bar press response

Six groups of six rats were run for 15-min daily sessions in an operant situation under either magnesium pemoline (MP) or saline Conditions. The design consisted of four days of acquisition followed by two days of extinction repeated four times. The results indicated that there was a slight tendency for MP to maintain more resistance to extinction as measured by response rate. The differential resistance is decreased by further acquisition-extinction sessions beyond the second set. The possible facilitating effects of MP are apparently reduced by the repeated exposure to the acquisition-extinction conditions.

Effect of magnesium pemoline on avoidance conditioning and intertrial activity in two strains of inbred mice

Magnesium pemoline was found to have a differential effect on behavior depending upon genotype. The drug resulted in increased activity and reduced avoidance scores for the fast-conditioning C3H strain of mice, whereas it significantly increased avoidance scores and activity for the slow-conditioning ST/bJ strain. The effect of magnesium pemoline on behavior is discussed in terms of an inverted-U relationship between reactivity and learning.

Effects of magnesium pemoline on shock avoidance conditioning and on various chemical measures

Rats fed magnesium pemoline showed enhanced conditioning and decreased RNA and protein synthesis.

Effects of magnesium pemoline on food and water intake in rats

A decrease in food intake appears following single injections of placebo or magnesium pemoline. Continued placebo injections do not produce this decrease while continued magnesium pemoline injections do maintain this decreased food consumption. Water consumption is not altered by these injections.

A preliminary evaluation of magnesium pemoline in chronic schizophrenic patients.

Magnesium pemoline was investigated for its possible beneficial effects upon intellective and memory functioning and clinical psychiatric status of chronic schizophrenic patients. Sixteen patients received magnesium pemoline for eight weeks in dosages beginning at 12.5 mg. daily and increasing after two weeks to 25 mg. daily. Four patients received magnesium pemoline at these same dosages in addition to already effective antipsychotic medications. Eight subjects from the larger group received a second fourweek trial of magnesium pemoline; four of these patients received 100 mg. daily and the other four were given 12.5 mg. every other day. All study subjects were evaluated by means of repeated psychological and psychiatric procedures as well as by extensive laboratory examinations and special tests for cardiac and dermatologic effects. Results suggested that magnesium pemoline in dosages of 12.5 mg. to 25 mg. daily has no therapeutic efficacy in chronic schizophrenic patients. Possible antidepressant activity was suggested at a dosage of 12.5 mg. every other day, but this was based on data for only four subjects and requires replication in a larger and more appropriate patient group. Addition of magnesium pemoline to an already effective regimen of antipsychotic drugs produced no further significant benefit. The effect of magnesium pemoline upon intellective and memory functioning in chronic schizophrenic patients remains equivocal. Suggestion of possible slight enhancement of such function was seen with administration of 25 mg. daily, but even if this could be clearly corroborated the degree of change does not appear to be of real clinical significance in patients of this type. With the exception of a transient rise in pulse rate and suggestion of some insomnia, evaluations for toxicity and side reactions were consistently negative at all dosages. In summary, findings from these pilot investigations offer no support for further study of magnesium pemoline in chronic schizophrenic patients.

Biochemical and behavioral effects of magnesium pemoline.

Magnesium pemoline decreased training response latency in a shock avoidance situation, of male, but not female rats. The groups did not differ on a 24-hour retention test. The drug had no discernible effect on orotic acid incorporation into brain or liver RNA or upon RNA content. Liver RNA was slightly increased, probably because of stimulated drug metabolism. Magnesium pemoline did not augment hormonal stimulation of nuclear RNA synthesis and, therefore, does not generally stimulate RNA synthesis. The behavioral effects of magnesium pemoline are probably not related to RNA metabolism.

Protective effect of magnesium pemoline against lethal doses of x-irradiation.

Magnesium-Pemolin, bekannt als gedachtnisstarkendes Arzeimittel, besitzt eine erhebliche Schutzwirkung gegen ionisierende Strahlen. Dieser strahlentherapeutische Effekt betrifft sowohl kurze, als auch langdauernde Wirkungsperioden.

Magnesium pemoline: failure to affect in vivo synthesis of brain RNA.

The effect of magnesium pemoline on the synthesis of brain RNA in vivo was studied. No significant effect either on the concentration of RNA or on the uptake of H(3)-uridine into RNA was detected.

Effect of magnesium pemoline on learning and memory of a one-way avoidance response

This study tested the effects of 10 mg/kg of magnesium pemoline on the learning of a one-way avoidance response. Neither the rate of learning, nor the rate of extinction was affected by the administration of magnesium pemoline.