Biobehavioral Reviews最新文献

In experimental designs used by a number of disciplines, raw data are transformed into ratios and statistical analyses are performed on the ratio data. Although the designs themselves may be appropriate, the mathematical properties induced by ratio transformations can produce a loss of sensitivity in statistical tests. Since there are times when such designs must be used, it would be desirable to characterize the circumstances under which the statistical analysis of ratio data is or is not appropriate. To provide such information, a computer simulation approach was used to generate bivariate normal observations X and Y which were analysed using: (1) an analysis of variance ignoring the covariate; (2) an analysis of covariance; (3) an analysis of variance on the ratio Y/X. Comparisons were made between the three models by accumulating the number of rejections (1−β) on critical F-values for each model. Results taken from over a million analyses are discussed for a wide range of specific treatment effects and known correlations between the independent variable X and the dependent variable Y.

Recent research concerning maternal aggression in mice is reviewed and a model describing the events controlling the behavior is proposed. It appears that hormones secreted during pregnancy produce growth in the nipples. This growth enables the female to receive suckling stimulation from her young following parturition. Suckling-induced changes, of which hypothalamic alterations are strongly suspected, may be responsible for the initiation of aggression. The frequency of suckling and exteroceptive stimuli from young maintain the hypothalamic changes responsible for aggression. Suggestions for future research in maternal aggression are proposed. The relevance of this work to other areas of psychobiology is also considered.

A central theory of reinforcement is presented, which is based on the assumption that reinforcers act directly on dynamic memory processes. One prediction from the model is that learning of various tasks should be improved as a result of reinforcement presented during the period of short-term memory. To test this hypothesis the reinforcers food, water or electrical stimulation of the lateral hypothalamus were presented posttrial in diverse learning situations. Posttrial food reinforcement facilitated passive avoidance learning in mice. In rats 30 sec of posttrial reinforcing brain stimulation facilitated learning of a shuttle-box avoidance, step-down avoidance, and small box avoidance. Appetitive T-maze learning was improved with posttrial reinforcing brain stimulation contingent on errors. Learning of a conditioned taste aversion was not influenced by reinforcing brain stimulation presented during the CS - UCS interval.

Studies on the effects of sodium phenobarbital on the ingestion of various sapid solutions in rats are reviewed and discussed. In the first three studies reported, the effects of phenobarbital on forced consumption of alcoholic and nonalcoholic solutions in water deprived rats were examined. The results of these studies indicated that phenobarbital can produce a taste aversion to ethanol solutions but not to nonalcoholic solutions in animals previously acclimated to these solutions. These data suggested a specific pharmacological interaction between this barbiturate and alcohol and a series of experiments on the effects of phenobarbital on voluntary alcohol consumption in rats was performed. The results of these studies indicate that chronic administration of certain doses of phenobarbital decreases preference for sweetened and nonsweetened 3% and 6% ethanol solutions but does not affect preference for non-alcoholic glucose and saccharin solutions. Similar administration of 30 mg/kg amobarbital, 80 mg/kg barbital, 2.5 mg/kg diazepam, 1.0 mg/kg methyprylon, and 10.0 mg/kg methaqualone did not alter intakes and preference for a 6% ethanol solution. The apparent specificity of phenobarbital in reducing ethanol consumption is discussed.

The interaction of psychological stresses with organismic susceptibility to disease states has been at least implicitly assumed for many years. Recent emphais on cardiac risk factors has provoked much concern regarding the role of psychological stress in the etiology of cardiovascular diseases, such as hypertension. The literature reviewed shows that controlled psychological stress has a profound influence on cardiovascular parameters such as arterial blood pressure. Furthermore, there is considerable evidence that the nervous system and renal system are intimately involved in the production of these cardiovascular adjustments. Unfortunately, the research to date has not provided any conclusive evidence which suggests that psychological stress results in chronic cardiovascular pathologies. It is suggested that psychological stress is not both a necessary and sufficient condition for the production of cardiovascular disease. Rather the hypothesis is advanced that an organism must have a physiological predisposition for the pathology before psychological stress will precipitate the disease.

The effects of benzodiazepines on conditioned and unconditioned behavior are reviewed. These compounds appear to decrease the suppressive effects of aversive stimuli such as electric shock or nonreward on behavior, a result usually related to their anxiolytic activity in human medicine. However they do not attenuate but rather increase the facilitatory effects of aversive stimuli on behavior. This last result points out the role played by changes at the response level and it is suggested, from the available evidence, that benzodiazepines induce response perseveration by preferentially interfering with the response-produced feedbacks. This effect is further complicated by the role of drug factors and the possibility of the drug treatment to combine to environmental cues and induce state-dependency. Further work is needed to examine the interference of benzodiazepines treatment with the facilitatory effects of aversive stimuli on behavior on one hand, and to determine the respective role of exteroceptive cues and response-produced feedbacks on the other hand.

Visually evoked response (VER) after-discharge (AD) research is reviewed. Neurophysiological and neuroanatomical contributions are developed in terms of the thalamic generating mechanisms of VER ADs, with specific reference to the dorsal lateral geniculate nucleus. The association between a variety of brain systems including the mesencephalic reticular formation, superior colliculus, ventral lateral geniculate nucleus, pulvinar, hippocampus and medial geniculate in terms of the modulation and functional significance of the VER AD is provided. The neuropharmacology of VER ADs is likewise examined with respect to the development of an experimental epilepsy model, this being dependent upon the observations that convulsants markedly augment while anticonvulsants significantly attenuate VER ADs. Cholinergic and catecholaminergic systems are also discussed in terms of their relevancy with the neuropharmacology of VER ADs. A variety of behavioral relationships have been determined and are likewise reviewed. A unifying theme of the behavioral research associated with VER AD elicitation and elaboration has been with an underlying arousal dimension. The multidisciplinary approach taken by VER AD research suggests the direct application of this type of orientation for a variety of behavioral research areas.

Recently opiate receptors have been discovered in the central nervous system (CNS) which show specificity for opiate drugs as well as for a range of endogenous polypeptides. These endogenous opiates are released during stress and under those conditions have analgesic properties, also their peripheral injection leads to analgesia. In the present paper a common biochemical substrate which involves these polypeptides as an explanation of pharmacological and psychological analgesics is proposed. The evidence for this thesis is reviewed and further experimental tests are suggested.

The rate-dependent effects, and several exceptions, of amphetamines on schedule-controlled behavior have been well documented. A hypothesis that most of the rate-dependent effects and exceptions are the result of interaction and competition with other amphetamine induced activities, e.g., locomotion and stereotypy, is reviewed and discussed. The evidence strongly suggests that such a competing-response process does occur, particularly at higher dose levels. The process is interpreted as being consistent with such anomolous results as amphetamine's lack of a reliable effect on high rate bursting in timing schedules, the differential effects of amphetamine on the low rate timing behavior of pigeons and rats, the lack of an enhancing effect of amphetamine on low rate behavior suppressed by aversive stimulation, and the apparent lack of systematic effect of amphetamine on very low rate behavior.