Ethological analysis of morphine withdrawal with different dependence programs in male mice.

This work was performed to clarify the differences between a long or short development of morphine dependence as well as between a recently installed or a long-term dependence. Morphine withdrawal in rats is a well-characterized phenomenon but this is not so in mice. A study of the principal withdrawal signs have been performed in mice, evaluating their specificity and particular profile of appearance in each type of dependence. Mice were divided into two groups that received increasing doses of morphine every 24 h, three groups that received increasing doses of morphine twice a day for 3 days, and a control group that received saline. Naloxone-induced opiate withdrawal was evaluated following short-term exposition to morphine [Test 1 (T1)--saline and Test 2 (T2)--naloxone] and long-term exposition to morphine [Test 3 (T3)--naloxone and Test 4 (T4)--saline]. Morphine administration twice a day is more effective in inducing opiate dependence than once a day, and with the latter, the duration of morphine exposure increases the intensity of withdrawal signs. Weight loss, diarrhea, body shakes, jumping, paw tremor, ptosis, piloerection, and the modified Gellert-Holtzman scale for mice are specific patterns of naloxone-induced withdrawal. The first four signs allow the discrimination between different levels of opiate dependence. Body care, piloerection, and the modified Gellert-Holtzman scale could be useful to detect conditioned withdrawal.

Ethological confirmatory factor analysis of anxiety-like behaviour in the murine elevated plus-maze.

The elevated plus-maze has been used in animal research to measure anxiety since 1985 and is currently the most widely used animal model of anxiety. Since this paradigm has been the subject of several principal components analyses, it is well qualified for confirmatory factor analysis research. The current report builds on the substantial theoretical knowledge and empirical data obtained from these structural analyses with a view to obtain further progress in the evolution of our understanding of animal anxiety in the elevated plus-maze. The purpose of the present report was two-fold: (a) to test if the a piori imposition of a 3-factor model, or a competing 2-factor elevated plus-maze model, would fit our sample (n=200 CD-1 mice) data in each of two trials within an inferential confirmatory factor analytic framework; (b) provide a well-fitting model that confers indicator variables that can most effectively and parsimoniously measure underlying constructs of elevated plus-maze behaviour. Multiple model-fitting criteria were used, and issues related to data non-normality, outliers, replicability of the model, sampling error and error of approximation in the estimation of final model fit were addressed. The final 2-factor model, with estimated error covariance between two different pairs of indicator variables, was a good fit on the trial-1 data, although it was necessary to allow unprotected stretch attends to non-significantly cross-load on factor-2. A 2-factor model also fit the trial-2 data from the present analysis, although it was necessary to allow closed arm time ratio to negatively cross-load on factor-1. These results indicate that inferential hypothesis testing and model building procedures within a confirmatory factor analysis framework produces interpretable animal anxiety indices in the elevated plus-maze. Moreover, a 2-factor, rather than a 3-factor model, parsimoniously and unambiguously explained the underlying constructs of anxiety-like mouse behaviour in the elevated plus-maze in the present study. Taken together, a reduction in the growing number of behavioural indices reported in elevated plus-maze pharmacological studies is suggested.

Major depression: behavioral markers of depression and recovery.

The concepts of psychosocial and psychomotor inhibition characteristic of major depression are based primarily on clinical observations. It is possible to describe and define these two types of inhibition by means of a systematic, quantitative ethological (behavioral) approach, which singles out precise and significant behavior markers. This investigation focuses on the behavioral features of psychosocial and psychomotor inhibition in 11 hospitalized depressed subjects and their changes during clinical recovery. The hypothesis that major depression is characterized by a significant reduction of social interaction is tested (psycho-intellectual inhibition is not addressed). Results show significant behavioral differences between depressed and recovered subjects with depression being characterized by a significant reduction of social interaction, whereas self occupation and body mobility are reduced to a lesser degree. Behavior markers for depression include nonspecific gaze, withdrawal, no mouth movements, no eye region movements, and social inactivity. Behavior markers for recovery include socially interested, social smile, verbal social initiative, speech, nod, raised eyebrows, wrinkled eyebrows, social laughter, gesticulation, drum one's fingers, point, and help. Findings point to tendencies toward two types of major depression and two types of recovery. A companion paper (Schelde, this journal) addresses theoretical issues.

Major depression: behavioral parameters of depression and recovery.

This paper reports on an ethological study of 11 depressed hospitalized subjects. Major depression and recovery are described in terms of general behavioral traits, i.e., behavior parameters. The hypothesis, that the primary behavioral feature of major depression is a reduction of social interaction and that secondary features are reduced self occupation and body mobility (posture flexibility) is tested. The behavioral patterns of depression and recovery are described and elucidated by 12 defined behavioral parameters, eight of which show significant changes between the first and the last hospital week. Findings from six of the parameters are consistent with the hypothesis and demonstrate social inhibition during depression; interactions between depression and nonverbal behavior are particularly striking. Findings also confirm that, during depression, self occupation and body mobility are reduced to a less significant degree than social inhibition. Possible relationships between findings and agitated forms of major depression are discussed. A final section examines findings in an evolutionary context and emphasizes their clinical implications.

[The stepwise statistical analysis of free behavior in rats]. / Poétapnyi statisticheskii analiz svobodnogo povedeniia krys.

Logically justified sequential application of a number of statistical methods makes it possible to describe comprehensively free behavior of animals. In particular, only in the free behavior experiments it was shown that some behavioral indices of August rats were less variable than those of Wistar rats. Moreover, the results of statistical analysis suggest that August rats are less resistant to stress than Wistar. Additional studies had to be conducted earlier in order to draw the analogous conclusions. On the basis of application of correlation and multivariate statistical analysis it was shown that the horizontal motor activity can be the most important characteristic describing the free behavior due to its maximal informativity.

[A method for evaluating the zoosocial behavior of rats in psychopharmacology]. / Metodika otsenki zoosotsial'nogo povedeniia krys v psikhofarmakologii.

The method was proposed for experimental assessment of the drug psychotropic spectrum in rats under pair interaction conditions. The method was based on the recording and analysis of the main behavioral elements with a specially developed point scale. A study was done on spectra of the diazepam, amphetamine, and desipramine activity. The results of pharmacoethological analysis confirm the effectiveness of the proposed method for the assessment of psychotropic spectrum of the well known drugs (diazepam, amphetamine, desipramine), as well as new pharmacological compounds.