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The relationship between the birth order and materialism scores was investigated using materialism conceptualized as a consumer value. Data were collected from 275 alumni of a major southwestern university. The analysis indicated that first-borns in this sample scored significantly lower on materialism than younger siblings.
Pedunculopontine tegmental nucleus (PPTg) lesions block place preferences to drugs or food only when animals are nondeprived. PPTg lesions also disrupt operant responding, but lesioned rats cannot discriminate active from inactive levers. It is not clear, therefore, whether PPTg lesions block reward or disrupt the ability to differentiate changes in reward magnitude. These hypotheses were tested by measuring sucrose consumption, choice, and contrast effects after PPTg lesions. Both sham and lesioned rats consumed greater amounts of a sucrose solution as the concentration and level of deprivation were increased. Given a choice between 2 solutions, all rats consumed more of the higher concentration. Both groups exhibited contrast effects when the concentration was shifted from 32% to 4% within a session. Somewhat surprisingly, lesions increased sucrose intake when rats were food-restricted. These results suggest that PPTg lesions do not disrupt primary motivation or the ability to evaluate and respond to changes in reward strength.
Experimental and clinical observations were made to treat abnormal sexual behaviour. The most common cause of abnormality was mismanagement of the animal; over-use and rough treatment at service and too-frequent ejaculation during winter had a detrimental effect on the behaviour of young stallions. Pain due to injury incurred at copulation or when associated with mounting attempts was also a common cause of impotence. Most impotent stallions responded well to re-training and recovery can be achieved without pharmacological treatment in most cases.
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The role of cholecystokinin (CCK) in reducing separation-induced ultrasonic vocalization (USV) was examined by peripheral administration (of the selective CCK(A) receptor antagonist devazepide to 10-11-day-old rats. Pups placed alone for 2 min emitted a mean of 55.1 USV/min. When placed on a paper towel wet with warm, sweet milk, USV rate decreased to 23.2/min for the following 8 min. Devazepide (150-600 microg/kg IP) prevented this USV reduction, but did not increase feeding. In contrast, USV reduction produced by contact with the anesthetized dam was not affected by devazepide. Similarly, the opiate antagonist naltrexone (0.5 and 1.0 mg/kg) has been shown to block morphine-induced USV decrease in pups away from the dam, but was ineffective when USV reduction was induced by the presence of the dam (Blass et al., 1990; Carden & Hofer, 1990). The current findings suggest that CCK's role is specific, in that it mediates milk- but not dam-induced quieting of USV. The results, however, are not incompatible with the possibility that CCK and opioids are part of multiple, redundant pathways that mediate the quieting of USV by the dam.
In considering intravenous injection of lipid as a model of fat embolism, contamination is frequent and purity must be demonstrated. Musculoskeletal trauma causes mild arterial hypoxia whereas intravenous pure triolein 0.1 mg/kg does not. Trauma produced a leukocytosis and elevated sedimentation rate not found in the lipid injected dogs. Evidence for consumptive coagulopathy was found in the trauma group but only a mild thrombocytopenia resulted from intravenous triolein. The traumatized dogs demonstrated an increase in the triglyceride level, an increase in the cholesterol phopholipid ratio and an increase in the cholesterol containing beta and prebeta lipoprotein fractions, all of which could lead to formation of pulmonary fat emboli containing cholesterol.
In experiments on 6 dogs it has been shown that in the EPs led from the hippocampus in response to electrostimulation of limbic structures and from the latters at the hippocampus stimulation, initial negativity, after positivity and late negative wave are the most stable components. At transition from one functional state to another two latter waves are subjected to the greatest changes. Amplitude-temporal characteristics of intralimbic EPs depend on the level and type of motivation, degree of emotional stress and properties of conditioned reaction.
In a short historical overview some developments in the behavioural research of the hypothalamus of the rat are introduced. Especially the ventromedial and the lateral hypothalamus have received much attention in the past. Numerous different behavioural effects have been described as the result of some kind of activation or inactivation of parts of the hypothalamus in the rat. Questions concerning the topographical distribution and the specificity of the effects observed, are addressed in the later parts. These behavioural observations were very important for the comparison with our anatomical observations concerning the hypothalamus, including the topographical organization of some afferent and efferent relationships. Non-synaptic or paracrine communication may play an important role in the hypothalamic effects on the organization of behaviour.
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A study has been made of the influence of disulphiram--a drug that lowers the level of norepinephrine and DOPA which restores its content in brain tissues,--on motivational and reinforcing effects caused by the action of a gradually increasing current on the self-stimulation (SS) zones. It has been shown that disulphiram, while suppressing motivational reactions does not exert such an effect on SS reactions. A half of the studied animals showed in these conditions an increased SS frequency. During disulphiram action (on the second day) DOPA restored motivational reactions and inhibited SS reactions. It is assumed that norepinephrine is involved in the mediatory system activating goal-directed motivational behaviour, but it does not constitute, as it seems, the major mediator of the reinforcement system.
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