Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, Lavrentieva 10, 630090 Novosibirsk 90, Russia. npopova@bionet.nsc.ru
The influence of deficiency of monoamine oxidase A (MAO A) gene and the lack of enzyme MAO A on the behavior of transgenic mouse strain (Tg8) was studied. It was shown that MAO-A-lacking mice differed from mice of the wild-type strain C3H/HeJ (C3H) by an attenuated acoustic startle response, prepulse inhibition (PPI) was unchanged. In Tg 8 mice, the exploratory nose-poking in the holeboard test as well as exploratory line crossing in the "light-dark" test were decreased. No effect of MAO A deficiency on locomotor activity was found. No alcohol preference or difference between Tg8 and C3H in ethanol consumption in the free-choice test has been found, although an increase in alcohol tolerance has been demonstrated. Ethanol-induced (0.3 g/100 g ip) sleep latency was longer, duration of sleep was shorter and ethanol hypothermia was reduced in MAO-A-lacking mice. Comparison of effects of MAO A knockout with those of irreversible MAO A inhibitor clorgyline (5 and 10 mg/kg ip) on C3H mice showed a similar reducing effect on ethanol-induced sleep, but potentiated ethanol-induced hypothermia. Clorgyline administration provoked a tendency to decrease of exploratory activity in the nose-poking test and decreased the frequency of exploratory rearings in the light-dark test. Clorgyline (5 and 10 mg/kg) did not affect the acoustic startle response, but a dose of 5 mg/kg diminished PPI. Therefore, Tg8 mice exhibited a decreased startle response and exploratory activity and an increased tolerance to ethanol. A similar increase in tolerance to ethanol-induced sleep and a tendency to decrease exploratory behavior were displayed by clorgyline. Other effects on behavior were different, suggesting the influence of long-lasting action of MAO A knockout and the involvement of a compensatory mechanism in Tg8 mice.
F-11 lubricant is used in synthetic fibers industry for the polyamide fibers processing. LD50 in intragastric administration is over 11,000 mg/kg. Acute action threshold (limac) is 180 mg/m3 (as evidenced by changes of the investigatory reflex). Chronic action threshold (limch) is 100 mg/m3. MAC in the air is 5 mg/m3, hazard class III. F-11 lubricant is a moderately hazardous chemical compound.
A single administration of the new lithium compound with prolonged action formed on the basis of lithium oxyburate produces an antiblepharoptosis effect in rats with reserpine depression for 24 to 48 h. It optimally prevents the development of "reserpine-desynchronization" in rats when prescribed in the morning at intervals of 48 h.
Long experience of defeat in daily social intermale confrontations and permanent living with aggressive males under sensory contact conditions [Kudryavtseva (8)] has been shown to produce changes in the patterns of submissive behavior of male mice of C57BL/6J strain. The submissive males after 20 defeats demonstrated passive defense postures instead of active defense and withdrawal which they had displayed in first encounters. Moreover, new immobile postures appeared, which were very rare in the first confrontations. Submissive animals displayed a decrease of ambulation in the open-field test and increase the immobility time in the Porsolt's test. Chronic treatment with imipramine prevented the increase of "depressiveness" estimated by means of the Porsolt's test. There was a loss of weight and some disturbances in gastrointestinal functions. The data are discussed in terms of the development of depression in submissive male C57BL/6J mice as a result of chronic unavoidable social stress.
Suppression of the cell component of the immune system and open-field behavior developing in OXYS rats by the age of 3 months are regarded as manifestations of accelerated aging. Stimulation of cell-mediated immune response with BCG vaccine caused a dose-dependent increase of orientation and exploratory activity of OXYS rats in the open field test to virtually the same level as in Wistar rats.
