Showing papers in "Psychopharmacology in 1970"
TL;DR: Comparison of rats given single or multiple injections of p-chlorophenylalanine was used to assess non-serotonergic actions of the drug as well as providing information on the behavioral effects of serotonin (5-HT) depletion.
Abstract: Comparison of rats given single or multiple injections of p-chlorophenylalanine (PCA) was used to assess non-serotonergic actions of the drug as well as providing information on the behavioral effects of serotonin (5-HT) depletion. In Experiment I all groups acquired an active avoidance response in accordance with decreased levels of 5-HT in the CNS and independently of probable PCA or phenylalanine levels. In Experiment II 5-HT depletion facilitated passive avoidance; again, independently of PCA levels. In Experiment III rats were run in an open field for 15 min with or without periods of extra stimulation by intense light or sound. Serotonin-deficient animals were more active than controls under conditions of extra stimulation but slightly less active without extra stimulation. Experiment IV showed that PCA in doses that do not reduce ad libitum drinking can depress quinine intake. It is suggested that 5-HT depletion makes rats more “reactive” to external stimulation.
190 citations
TL;DR: An antagonism between morphine and amphetamine is demonstrated but the anti-amphetamine effect of morphine is different from that of the neuroleptic drugs.
Abstract: Small single doses of morphine (1 mg/kg s.c.) and of amphetamine (1 mg/kg s. c.) induce excitation in rats. Locomotion and rearing are selectively stimulated by amphetamine, and grooming by morphine. Higher doses of morphine (5 mg/kg s. c.) cause sedation or catalepsy (20 mg/kg s. c.) but no stereotypies are seen as after amphetamine (10 mg/kg s. c.). Repeated doses of morphine induce stereotyped behaviour, which is inhibited by nalorphine. An antagonism between morphine and amphetamine is demonstrated but the anti-amphetamine effect of morphine is different from that of the neuroleptic drugs. Catecholamines in the basal ganglia may play a role in these behavioural effects of morphine.
160 citations
TL;DR: Regular users of marijuana (cannabis sativa) were given smoked and orally administered marijuana, a placebo, or alcohol and appeared to be mild intoxicants in a laboratory setting.
Abstract: Regular users of marijuana (cannabis sativa) were given smoked and orally administered marijuana, a placebo, or alcohol. They were unable to distinguish between smoked marijuana and the tetrahydrocannabinol-free placebo. The oral administration of tincture of cannabis produced primarily dysphoric symptoms and was similar to alcohol in this respect. The smoked marijuana altered pulse rate, time estimation, and EEG, but had no effect on a measure of field dependence or on a digit symbol substitution task. Both drugs appeared to be mild intoxicants in a laboratory setting. Consideration of the dose, prior experience with drugs, setting, and possible cross tolerance of marijuana and alcohol are important in evaluating the significance of the clinical effects.
152 citations
TL;DR: The evidence that NA in some experimental conditions increases locomotor activity of rats supports the hypothesis that NA regulates processes in the central nervous system which stimulate behaviour.
Abstract: The behavioural effects of NA injected without narcosis into the lateral brain ventricle of the rats were studied with two different techniques. Rats were classified according their normal level of exploratory activity into three groups: high, medium and low. It was shown that NA in a dose of 10 μg increased locomotor activity only in animals of low activity; a dose of 50 μg increased locomotor activity in all the animals; and a dose of 200 μg induced a complete abolition of locomotor activity and a stuporose syndrome lasting 2 hours. The evidence that NA in some experimental conditions increases locomotor activity of rats supports the hypothesis that NA regulates processes in the central nervous system which stimulate behaviour.
130 citations
TL;DR: The subjective effects of cyclazocine and nalorphine were differentiated from the effects of other drugs such as morphine, pentobarbital and LSD when the overall pattern of effect was considered.
Abstract: The subjective effects of two doses of cyclazocine (0.6 mg and 1.2 mg/70 kg), nalorphine (16 and 32 mg/70 kg), no-drug and placebo were compared with 32 opiate addicts using drug sensitive scales of the Addiction Research Center Inventory (ARCI) items. The effects of these narcotic antagonists were highly similar on ARCI scales and items. Both drugs produced a general drug effect, difficulty in focusing eyes, physical weakness, tiredness, poor motivation, moodiness, misery, anxiety, tension, hallucinations, changes in sensation and perception, and inefficiency of physical, cognitive and social functions. Cyclazocine was 15–26 times more potent than nalorphine. The effects of cyclazocine and nalorphine were differentiated from the effects of other drugs such as morphine, pentobarbital and LSD when the overall pattern of effect was considered.
118 citations
TL;DR: Large bilateral lesions affecting 30–90% of the corpus striatum inhibit stereotyped behaviour in rats injected subcutaneously with amphetamine, but do not prevent rage reactions induced by injection of a monoamine oxidase inhibitor followed by injections of l-dopa.
Abstract: Large bilateral lesions affecting 30–90% of the corpus striatum inhibit stereotyped behaviour in rats injected subcutaneously with amphetamine, but do not prevent rage reactions induced by injection of a monoamine oxidase inhibitor followed by injection of l-dopa. The stereotyped phase normally following this rage reaction is, however, absent in the operated rats. Small bilateral lesions in the corpus striatum (5–20%) cause a modified amphetamine stereotypy and prevent the usual cataleptic behaviour produced by subsuctaneous injection of a neuroleptic drug (perphenazine). Additional ablation of the overlying dorsal cortex enhances these behavioural effects without qualitative changes. Both amphetamine and neuroleptics seem thus to mediate their behavioural effects through dopaminergic mechanisms in the corpus striatum.
112 citations
TL;DR: In this article, the inhibitory effects of four neuroleptic drugs on amphetamine-induced stimulation in a discriminated Sidman avoidance procedure in rats were measured, and the order of potency was haloperidol > pimozide > chlorpromazine > pipamperone.
Abstract: The inhibitory effects of four neuroleptic drugs on amphetamineinduced stimulation in a discriminated Sidman avoidance procedure in rats were measured. Amphetamine 0.63 mg/kg s.c. increased R (responses) and decreased W (warning stimuli), WR (warning responses) and S (shocks). Relatively low doses of all four neuroleptics antagonized the amphetamineinduced changes. The order of potency was haloperidol > pimozide > chlorpromazine > pipamperone. The duration of action was pimozide > haloperidol > pipamperone > chlorpromazine.
105 citations
TL;DR: It appeared that the post-ingestional effects of morphine provided primary reinforcement for the rats; they were able to regulate their daily intake of the drug after being injected with varying doses of it and they lost weight abruptly during enforced abstinence.
Abstract: Rats were induced to administer morphine to themselves by drinking solutions of it in preference to water; this behaviour was found to be a valid model of morphine dependence. Previous “passive” medication with morphine was not necessary; initial aversions for the bitter morphine solutions were converted into preferences after the rats were repeatedly given only morphine solutions to drink in order to relieve thirst. The consumption of solutions of quinine which were initially equally aversive did not increase, suggesting that the repeated pairing of a bitter taste with relief of thirst did not account for the preferences for the morphine solutions. It appeared that the post-ingestional effects of morphine provided primary reinforcement for the rats; they were able to regulate their daily intake of the drug after being injected with varying doses of it and they lost weight abruptly during enforced abstinence. There was also evidence that the bitter taste of morphine had become a secondary reinforcer for rats with established preferences.
104 citations
TL;DR: I think that some attention should be directed toward animal models for understanding some of the behavior disorders, and studies such as those of Young (1963, 1964 and 1966), with some modification, could be directed towards giving us a more complete grasp of the aberrant behavior seen in the human child.
Abstract: The findings reported in this review present a number of avenues of approach to the study of the effects of drugs on children. Many investigators have begun to classify the behavior of disturbed children on a number of sophisticated, but operationally simple procedures which allow some dissection of the behavior deficits. This type of approach can lead to a better understanding not only of the pathological condition but also to a better understanding of the way in which a drug works. An understanding of the manner in which amphetamines produce their therapeutic effect in the hyperkinetic child cannot be forthcoming from studies that only elaborate the pathological behavior. More attention must be paid to the function of the central and autonomic nervous systems and how these systems relate to the behavior of the child. Since many of the drugs that are useful in treating behavior problems in children have marked effects upon catecholamine levels in the brain, studies comparing urine catecholamine levels in various types of behavior disordered children after the administration of sympathomimetic amines might give specific direction to further research. Finally, I think that some attention should be directed toward animal models for understanding some of the behavior disorders. Studies such as those of Young (1963, 1964 and 1966), with some modification, could be directed toward giving us a more complete grasp of the aberrant behavior seen in the human child. Animal models can complement studies in humans and they have the further advantage of allowing a more complete biochemical and neuropharmacological study of behavior.
95 citations
91 citations
TL;DR: Experimental animals developed a preference for alcohol over water, tolerance for increasing doses of alcohol and alcohol dependence, as shown by withdrawal stress, and these data suggest the development of an addiction to the alcohol solutions.
Abstract: Wistar rats were induced to drink aversive alcohol solutions by electrical stimulation in the lateral-hypothalamus. They increased their home-cage intake of alcohol over that of control animals. Changes in alcohol-directed behavior continued after termination of the brain-stimulation treatment. Experimental animals developed a preference for alcohol over water, tolerance for increasing doses of alcohol and alcohol dependence, as shown by withdrawal stress. They consumed alcohol even when it was contaminated with quinine. These data suggest the development of an addiction to the alcohol solutions.
TL;DR: It was concluded that of the methods employed, the Gayer test was the only useful procedure to measure Δ9-THC content in mixtures and this was confirmed by the relationship found between Δ 9- THC content and activity using five semi-purified extracts.
Abstract: The structure activity relationships of four tetrahydrocannabinols and the pharmacological activity of five semi-purified extracts from Cannabis sativa were studied using four biological methods: corneal areflexia in rabbits (Gayer test) and catatonia, decrease of motor activity and suppression of isolation-induced aggressiveness in mice. Modifications in the structure of pure, natural Δ9-THC rendered the resultant compounds inactive only when activity was measured by the Gayer test; by the other three methods the activity ranged from 1/5th to equal to the activity of pure Δ
9-THC. It was concluded that of the methods employed, the Gayer test was the only useful procedure to measure Δ
9-THC content in mixtures. This was confirmed by the relationship found between Δ
9-THC content and activity using five semi-purified extracts.
TL;DR: Subjects with high as compared with low rates of adrenaline and noradrenaline excretion were more efficient in terms of both speed and accuracy of performance.
Abstract: Physiological and psychological reactions were studied in 40 subjects under four different conditions. In Session I the subjects received electric shocks according to a random schedule which they could not influence. In Sessions II and III a choice-reaction task was performed, and half of the subjects were punished for slow performance, the degree of situational control exerted by the subjects being greater in Session III. Session IV was spent by all subjects in passive relaxation. Punishment produced a rise in both adrenaline and noradrenaline release. By increasing the subject's control over the situation it was possible to counteract the adrenaline increase, while noradrenaline release appeared unaffected. On the whole, subjects with high as compared with low rates of adrenaline and noradrenaline excretion were more efficient in terms of both speed and accuracy of performance.
TL;DR: The behaviour of rats placed in a new environment was determined simultaneously by photocells and by direct observation, and for the testing of drugs, the use of activity cages seems to be more limited than has sometimes been supposed.
Abstract: The behaviour of rats placed in a new environment was determined simultaneously by photocells and by direct observation. Predictably, a typical photocell activity cage did not measure a simple or homogeneous pattern of behaviour even in undrugged animals: two components of behaviour, the number of walks across the cage and of rears onto the hind feet, were correlated with photocell counts, but grooming was not. Even this agreement between observation and automation broke down if dexamphetamine was given; the correlation between rears and photocell counts was reduced by graded doses of dexamphetamine and by dexamphetamine-amylobarbitone mixtures, and the stimulant effect of dexamphetamine on walks was greatly exaggerated by the photocells. Such discrepancies were much smaller with amylobarbitone alone. For the testing of drugs, the use of activity cages seems to be more limited than has sometimes been supposed. Complex changes of behaviour are masked by the relatively crude photocell counts, but they may be detected by standardised observation. Watching the animals might also help with the development of improved automatic devices.
TL;DR: Both NA and DA are of importance in controlling motor activity and the degree of synthesis inhibition under the conditions described above was measured by estimation of the amount of 3H-DA and3H-NA formed from 3H -tyrosine.
Abstract: Mice were pretreated with the monoamine oxidase inhibitor nialamide, and sixteen hours later the dopamine (DA) β-hydroxylase inhibitor, bis-(4-methyl 1-homopiperazinylthiocarbonyl)-disulfide (FLA-63) or the tyrosine hydroxylase inhibitor α-methyltyrosine methylester (H44/68) was given. At different time intervals motor activity was measured and the brain levels of noradrenaline (NA) and DA were subsequently determined. Nialamide increased both motor activity and amine levels. Chlorpromazine changed this hypermotility into a marked hypomotility. After FLA-63 the NA level was moderately reduced whereas DA remained high and motor activity was only slightly reduced. When H44/68 had been given both NA and DA levels were reduced while a definite reduction in motility could be observed. In these nialamide pretreated animals the synthesis inhibitors reduced catecholamine levels and motility much less than in normal animals. In separate experiments the degree of synthesis inhibition under the conditions described above was measured by estimation of the amount of 3H-DA and 3H-NA formed from 3H-tyrosine. It was concluded that both NA and DA are of importance in controlling motor activity.
TL;DR: Analysis of the data revealed that the source of r.t. differences may be ascribable to superior signal detection or possibly decision time (pre-motor components) rather than limb transport time components of the total reaction-time.
Abstract: The reaction-times (r.t.'s) of 18 male and 9 female out-patients under treatment with methadone for heroin addiction, were compared with those of control subjects who were either non-drug users or had recently been withdrawn from narcotic drugs. Three different r.t. tests were used: a simple visual, simple choice and a multiple discrimination, multiple choice r.t. The median r.t.'s of subjects tolerant to average doses of 100 mg of methadone per day were either equal to or shorter than those of control subjects. Analysis of the data revealed that the source of r.t. differences may be ascribable to superior signal detection or possibly decision time (pre-motor components) rather than limb transport time components of the total reaction-time.
TL;DR: A relatively safe method is described for the screening of new monoamine oxidase inhibitors with respect to their potentiation of dietary and sympathomimetic amines, and marked potentation of the bradycardia-inducing properties of the amines was found.
Abstract: A relatively safe method is described for the screening of new monoamine oxidase inhibitors with respect to their potentiation of dietary and sympathomimetic amines. Studies of such a compound, Clorgyline, and its interactions with oral tyramine and phenylephrine given by mouth to three doctor-volunteers are described. Marked potentiation of the bradycardia-inducing properties of the amines was found.
TL;DR: It was concluded that even the depressant effects on motility, seen after administration of L-DOPA, are probably mediated at least in part centrally, simply by letting more of the DOPA injected pass through the blood-brain barrier and form dopamine intracerebrally.
Abstract: Mice were given L-DOPA i.p. in doses ranging from 7.8 to 500 mg/kg with and without previous administration of MK 485, a compound capable of inhibiting extracerebral dopa decarboxylase. In addition, dexchlorpheniramine together with MK 485 was given before L-DOPA to some of the animals. Spontaneous locomotor activity of the animals was measured and some preliminary biochemical determinations were performed of dopamine, noradrenaline and 5-hydroxytryptamine levels in brain. It was found, that L-DOPA had both depressant and excitatory effects on locomotor activity depending on dose, and that MK 485 caused a potentiation of both these effects, together with an increased dopamine production in the brain. Dexchlorpheniramine caused a further potentiation of the effects on activity, evidently without affecting the total dopamine level in the brain. On the basis of these data, it was concluded that even the depressant effects on motility, seen after administration of L-DOPA, are probably mediated at least in part centrally. Apparently MK 485 potentiates L-DOPA effects on activity, simply by letting more of the DOPA injected pass through the blood-brain barrier and form dopamine intracerebrally. Further investigations are required to obtain information on the mechanism of the DOPA-potentiating action of dexchlorpheniramine.
TL;DR: The long persistence of “relapse-tendency” in rats previously made physically dependent on morphine may be based on such long-term derangement of homeostasis coupled with “interoceptive” conditioning generated during daily cycles of primary abstinence from and relief by morphine in the “addiction” period.
Abstract: 1.
Measurements of 24 hr tap water consumption, body weight, “wet dog” shake frequency and free choice drinking (etonitazene, 5 mcg/ml versus distilled water) were made at intervals up to 434 days following abrupt withdrawal of morphine (from a daily maintenance dose level of 200 mg/kg i.p.) in one group of rats (“postaddicts”) and following termination of i.p. injections of saline in a control group of rats (“normals”).
2.
During the first five days after termination of injections, signs of primary morphine abstinence were observed in the “postaddict” rats: transient decrease in 24 hr tap water consumption and in body weight, and increase in “wet dog” shake frequency.
3.
Secondary morphine-abstinence phenomena, consisting of signicantly greater 24 hr tap water consumption and slightly higher “wet dog” shake frequency (compared with normal rats) were observed in “postaddict” rats over the 7th–23rd post-injection days. Thereafter, these differences persisted, but not at significant levels.
4.
In a no-choice test (etonitazene, 5 mcg/ml or water on different occasions) conducted between the 28th and 37th days after termination of injections, “post-addict” rats drank significantly more etonitazene than water, whereas normal rats drank slightly less etonitazene than water.
5.
In free-choice drinking tests (etonitazene, 5 mcg/ml versus water) conducted at intervals over a period of 434 days following termination of injections (morphine or saline), no significant differences in mean water consumption between “post-addict” and normal rats were observed. In contrast, “postaddict” rats drank significantly larger mean volumes of the etonitazene solution on every “relapse” test through the 336th and again on the 406th post-withdrawal day (but not on the 372nd or 434th day).
6.
It is concluded that in the “postaddict” rat a “need” for an opioid persists for about one year after abrupt withdrawal of morphine, and that this “need” is based on long-term derangement of homeostasis. although the physiological characteristics of such homeostatic derangement differ in the relatively short primary and more protracted secondary abstinence periods.
7.
The long persistence of “relapse-tendency” in rats previously made physically dependent on morphine may be based on such long-term derangement of homeostasis coupled, perhaps, with “interoceptive” conditioning generated during daily cycles of primary abstinence from and relief by morphine in the “addiction” period, through which the internal sensorial effects of opioids (morphine while receiving injections; etonitazene imbibed in “relapse” tests) may acquire secondary reinforcing properties.
TL;DR: In this paper, the influence of several factors viz. auditory stimulus, drug dosage, age, sex, strain, and cage size on aggressive behavior in rats was studied. But the results showed that the aggressive behaviour induced by apomorphine was not correlated with that induced by electrical stimulation nor with that inducing by killing mice.
Abstract: Apomorphine (1 mg/kg i.v.) has been found to induce aggressive behaviour in rats. Having studied the influence of several factors viz. auditory stimulus, drug dosage, age, sex, strain, and cage size, an experimental design was adopted. Using this design three populations were distinguished among 1524 pairs of rats studied: a) with no agression behaviour at all; b) with a moderate, short lasting and inconstant one; c) with a severe, long lasting and reproducible one. The aggressive behaviour induced by apomorphine was not correlated with that induced by electrical stimulation nor with that induced by killing mice. Several psychotropic drugs were found to antagonise this action: neuroleptics (except Reserpine), tranquillisers (Chlordiazepoxide, Diazepam, Meprobamate, Hydroxyzine), morphine and atropine.
TL;DR: The bar-pressing behavior of hungry rats was maintained by a fixed-ratio schedule of food reinforcement, and sensitivity to LSD was apparently unaffected by pretreatment with α-methyl-p-tyrosine (AMPT).
Abstract: The bar-pressing behavior of hungry rats was maintained by a fixed-ratio schedule of food reinforcement. At 5 and 12 days after pretreatment with p-chlorophenylalanine (PCPA), a subtreshold dose (20 μg/kg) of lysergic acid diethylamide (LSD) was found to disrupt this behavior. No such disruption occurred when PCPA pretreatment was followed by either a distracting external stimulus (tone) or a low dose of D-amphetamine (0.3 mg/kg). Sensitivity to LSD was apparently unaffected by pretreatment with α-methyl-p-tyrosine (AMPT).
TL;DR: It was concluded that these drugs selectively impaired inhibitory stimulus control of responding following administration of atropine, scopolamine, or d-amphetamine was essentially the same whether or not the tone was present.
Abstract: A discrete trial lever-pressing situation was developed for measuring the behavior of rats during repeated periods of reinforcement withdrawal following periods of 100% or 50% reinforcement. Behavior during the reinforcement and withdrawal period trials was learned rapidly and remained stable under the standard conditions. Atropine, scopolamine, d-amphetamine, and other compounds produced orderly, dose-related changes in withdrawal period trial responding.
TL;DR: The results support the view that strain differences in avoidance learning are more related to variations in strength of a kinetic drive than to strength of fear.
Abstract: Four inbred strains of mice were compared on an active and a passive avoidance task in a two-compartment cage. Active mice were trained to cross frequently between compartments to avoid shock; passive mice were shocked for crossing. Yoked controls in both procedures received shocks at the same time as experimentals. Strains learning the active task well did poorly in the passive task; strains poor in active learning were superior on the passive task. The results support the view that strain differences in avoidance learning are more related to variations in strength of a kinetic drive than to strength of fear. Chlordiazepoxide affected crossings similarly in actively and passively trained Ss; chlorpromazine reduced crossings in actively trained and increased crossings in passively trained Ss. This result is consistent with dual motivational systems differentially susceptible to alteration by administration of drugs. Chlordiazepoxide acts primarily upon kinetic drive; chlorpromazine upon fear.
TL;DR: Overall response rate varied with schedule, schedule value and morphine dose, and the relative rate change also varied with the type of schedule.
Abstract: Rats conditioned on three values of FR, VR, FI and VI food reinforcement schedules were administered 1.0, 3.0 and 6.0 mg/kg I.P. of morphine or saline. Overall response rate varied with schedule, schedule value and morphine dose. The effect of morphine on overall rate varied with baseline saline rate generated by schedules, and the relative rate change also varied with the type of schedule.
TL;DR: In chronic spinal dogs, LSD, mescaline, psilocin, 2,5-dimethoxy-4-methylamphetamine, methysergide and tryptamine facilitate the flexor reflex evoked by tetanic electrical stimulation of the toe and evoke the stepping reflex, but these effects are not antagonized by cyproheptadine.
Abstract: In chronic spinal dogs, LSD, mescaline, psilocin, 2,5-dimethoxy-4-methylamphetamine, methysergide and tryptamine facilitate the flexor reflex evoked by tetanic electrical stimulation of the toe and induce the stepping reflex. These effects are antagonized by chlorpromazine and cyproheptadine, but not by phenoxybenzamine. 5-Hydroxytryptophan and serotonin also facilitate the flexor reflex and evoke the stepping reflex, but these effects are not antagonized by cyproheptadine. These findings suggest that the mode of action of several LSD-like psychotogens is similar to that of tryptamine and is different from that of serotonin or 5-hydroxytryptophan.
TL;DR: Chlordiazepoxide (12 mg/kg) reduced the suppressive effects of a CER stimulus if the drug was given prior to CS-shock pairings if the behavior suppressed by the CS was either milk licking or lever pressing for food.
Abstract: Chlordiazepoxide (12 mg/kg) reduced the suppressive effects of a CER stimulus if the drug was given prior to CS-shock pairings. No attenuation of suppression occurred if the drug was given prior to the test for suppressive effects of the CS. This attenuating effect of chlordiazepoxide upon CER learning occurred if the behavior suppressed by the CS was either milk licking or lever pressing for food. The effect was dose-related with higher dosages causing a greater attenuation of CER learning.
TL;DR: Tryptamine, infused intravenously in man, facilitates the patellar reflex, dilates pupils and elevates blood pressure, which are consistent with the hypothesis that LSD-like hallucinogens interact with tryptamine receptors as one mode of action.
Abstract: Tryptamine, infused intravenously in man, facilitates the patellar reflex, dilates pupils and elevates blood pressure. It also causes changes in vision and hearing, as well as nausea, vomiting, dizziness, sweating and heaviness of body. These changes are similar to those produced by LSD-like hallucinogens and are consistent with the hypothesis that LSD-like hallucinogens interact with tryptamine receptors as one mode of action.
TL;DR: The smoking that did occur in the absence of both tobacco and nicotine indicates that the habit itself often exhibits functional autonomy from the physiological effects of nicotine.
Abstract: Measures of smoking rate and psychological effects of cigarettes with varying nicotine content were made in 15 subjects. While subjects did perceive differences in strength and quality of the experimental lettuce cigarettes as compared to their own brands, their smoking rates did not decrease differentially over the nicotine gradient. The decrement in smoking due to the experimental cigarettes persisted when subjects resumed smoking their own cigarettes. However, the smoking that did occur in the absence of both tobacco and nicotine indicates that the habit itself often exhibits functional autonomy from the physiological effects of nicotine.
TL;DR: Pre- and post-trial application of 0.15 mg/kg nicotine had, quantitatively and qualitatively, a very similar effect on the Hebb-Williams-test performance of rats, suggesting a beneficial effect of nicotine on higher integrative functions.
Abstract: Pre- and post-trial application of 0.15 mg/kg nicotine had, quantitatively and qualitatively, a very similar effect on the Hebb-Williams-test performance of rats. The performance of both treated groups, was for some of the problems of the second half of the test (composed of 12 problems), better than that of the control group. This result suggests a beneficial effect of nicotine on higher integrative functions. The irregularity of the effect from problem to problem of the test was discussed as a consequence of the structural differences between the problems of the test.
TL;DR: During the 14 day periods of lithium administration, cumulative sodium excretion was always greater in the lithium-treated rats, and brain sodium concentration was consistently decreased, and the mechanisms responsible for these changes are discussed and related to a possible mechanism of action of lithium in manic-depressive disease.
Abstract: Lithium carbonate was administered chronically in low doses (02 mEq/day) to rats on constant sodium diets The changes in external sodium and potassium balance and brain sodium and potassium concentration were compared to those of control animals Changes in external sodium balance were in some respects similar to those observed in patients treated with lithium During the 14 day periods of lithium administration, cumulative sodium excretion was always greater in the lithium-treated rats (p<001), and brain sodium concentration was consistently decreased (p<001) The mechanisms responsible for these changes are discussed and related to a possible mechanism of action of lithium in manic-depressive disease