Haloperidol does not alter a choice strategy for reinforcement value in cats

A blockade of the dopaminergic D1/D2 receptors by systemic administration of haloperidol (0.05-0.5 mg/kg) produced a dose-dependent increase in inhibition of conditioned alimentary behavior in cats under conditions of choice between a valuable delayed reward and a less valuable immediate reward. Administration of haloperidol produced a progressive decrease in the number of effective instrumental reactions, but did not affect the choice between short- and long-latency reactions and their mean latencies. The data obtained do not support a hypothesis that the blockade of dopaminergic receptors shifts behavior towards impulsive reactions. The reasons why the results do not support the hypothesis are discussed.     

Influence of blockade of the dopaminergic D1/D2 receptors on choice behaviour at different by validity reinforcements in cats

The influence of two selective antagonists of the dopaminergic receptors, raclopride (D2) and SCH 23 390 (D1) on behavior of "impulsive" and "self-controlled" cats was similar directed. A selective blockade of the dopaminergic D1/D2 receptors by use of raclopride and SCH 23 390 changed a behavioural choice strategy of two different by validity and delay reinforcements in impulsive cats, but did not change it substantially in "self-controlled" animals. Increase of doses of raclopride and SCH 23 390 led to decrease of a part of the short-latency and increase of a part of the long-latency reactions (pedal pressings) in a total number of all effective responses. This occurred only in "impulsive" animals, that indicates probably the decrease of impulsive properties of their behaviour. Both compounds did not affect the choice strategy (a low quality immediate vs. a high quality delayed reinforcements) in "self-control" animals, but elicited more errors and inhibitory responses in their behavior. The data obtained are not consistent with the "dopamine" hypothesis, which predicts increase of impulsivity under influence of dopaminergic antagonists. The reasons that might lead to the data obtained are discussed.     

Biotropic effects of geomagnetic storms and their seasonal variations

A substantial effect of geomagnetic storms on human health with a confidential probability P = 0.95 was revealed. The quantitative estimates of the biotropic effect are presented. For example, the frequency of occurrence of bursts exceeding the average number of hospitalized patients with mental and cardiovascular diseases during magnetic storms increases approximately 2 times compared with quiet periods (based on the data on 1983-84). The frequency of occurrence of myocardial infarction, angina pectoris, violation of cardial rhythm, acute violation of brain blood circulation during storms increases 2.1; 1.6; 1.6; 1.5 times, respectively compared with magnetically quiet periods (based on the data of 1992-96). A similarity of the seasonal distribution of the magnitude of the biotropic effect is revealed in the case of myocardial infarction and the number of magnetic storms: a maximum in the equinox and a minimum in summer.     

Mechanism of initiation of intracellular ice formation

Intracellular ice crystallization was studied by the method of cryomicroscopy in the systems modeling a biological suspension, such as erythrocyte concentrates. Initiation of crystallization by extracellular ice through hydrophilic channels has been shown to be the most probable mechanism of intracellular ice formation.