Automated method for measuring fighting behavior and locomotor activity of mice

Voluntary ethanol drinking increases locomotor activity in alcohol-preferring AA rats

This study explored, first, whether voluntary ethanol consumption produces locomotor stimulation in ethanol-preferring AA rats. Rats had continual access to water but access to a second bottle containing 10% ethanol, 0.1% saccharin, or water only for 10 min/day. Locomotor activity was significantly increased after the drinking in the ethanol group. Second, we compared the locomotor responses of AA and ANA (ethanol-avoiding) rats to IP ethanol (0.6 and 1.0 g/kg). Rats habituated to test cages showed no effects, but on a modified open field novel to animals there was a short increase in activity without any rat line difference. This activity increase might have resulted from a weak anxiolytic action of ethanol, indicated by the finding in the elevated plus-maze where IP ethanol (1.0 g/kg) increased the number of crosses from a closed arm to another in both AA and ANA rats. The results suggest that ethanol has reinforcing effects in AA rats when drunk but not when injected IP.

An automated method for recording scent marking in Mongolian gerbils

A device for the automated recording of scent-marking events in Mongolian gerbils (Meriones unguiculatus) is described. The method uses minute temperature changes occurring at the surface of marked objects to detect scent marking. These events are recorded by a computer together with the exact time and the location of the marked object. The data obtained with this temperature-sensitive recording method correlate well with data obtained in parallel by human observers. The measurement of the diurnal rhythm of scent-marking behavior for 5 consecutive days in an undisturbed male demonstrates the specific usefulness of this new recording method. In addition, this temperature-sensitive automated recording of scent-marking behavior may also be applicable in other animals that primarily mark protruding objects.

Lack of increased intermale fighting behavior in mice after low ethanol doses

The effect of ethanol on intermale fighting behavior, measured mainly as the total fighting time, was studied using Swiss-Webster mice in 5-min encounters in a neutral arena (i.e., not the home cage). Ethanol treatment compared to control treatment had no statistically significant effect on fighting behavior when given to both equal-sized members of a pair of males socially isolated for a) 5 or 10 days at a dose of 0.4 g/kg IP; b) 4 weeks at 0.8 g/kg IP; and c) 38 weeks at 0.4 g/kg IP. Moreover, no significant effect was found when ethanol was given only to the expected dominant member of a pair, that is, to: a) a male isolated for 48 weeks confronting a younger and smaller group-housed male at 0.4 g/kg PO; and b) a male that had been pair housed with a female conspecific for 5 weeks confronting a group-housed male of equal age and weight at 0.4 g/kg IP. The results suggest that under these conditions ethanol does not lead to increased fighting behavior in Swiss-Webster male mice.

Measuring behaviour: the tools and the strategies

Animal behaviour can be viewed as a stream of elements, which, once accurately described, can be counted and timed. Data acquisition techniques and tools are reviewed, and some strategies for collection and analysis of data using PC computers are suggested. Automated instruments are not satisfactory for the study of complex behaviour and as such systemic observation remains irreplaceable. IBM PC-type computers, with a wide range of analytical software (e.g., spreadsheets, statistical packages, technical graphics), are practical for data acquisition. Several systems which can satisfy different applications are reviewed. Some systems can communicate with a videorecorder, a facility which remarkably increases the accuracy of measurement; this is essential for meaningful analyses of the internal structure of behavioural streams (sequences, time patterns) or communication processes. The power of new tools enables behavioural measurement with the necessary complexity to allow a whole new set of questions to be addressed. However, it also increases demands for meaningful content and analysis of data.

Social isolation increases the stimulatory effect of ethanol on locomotor activity

The stimulatory effects of low alcohol doses are of great interest because of their role in human drinking and their possible relation to reinforcement from alcohol. The preferred animal model for studying them is the mouse. The effects of various doses of ethanol on locomotor activity were now studied in both group-housed mice and in mice socially isolated for 36-44 weeks. The housing situation was found to have a strong influence: a large stimulatory effect was observed in isolated mice but little effect was seen in group-housed animals. The results suggest that socially isolated mice are more sensitive to the stimulatory effect of ethanol on locomotor activity.

An adaptable microcomputer program for recording behavior durations

A versatile and easy to use program is described for monitoring and recording behavior durations on IBM-compatible microcomputers. The program also records frequencies and provides latency information. Among its more prominent attributes are its ability to accommodate a broad range of behavioral assays and the facility with which its operation can be mastered. It requires no specialized hardware and is capable of being used in conjunction with a number of commercially available software packages for statistical analysis.