Characteristics of the acquisition processes of discrete lever-press and shuttle avoidance responses (intertrial interval = 25 sec, warning duration = 5 sec with an escape contingency, and 1 session = 1 hr training/day) as well as those of the ambulatory activity were investigated in 6 strains of mice (dd, ICR, BALB/c, C57BL/6, C3H/He and DBA/2). In the lever-press avoidance situation, the dd, ...

From a panel of nine inbred mice strains intranasally infected with Streptococcus pneumoniae type 2 strain, BALB/c mice were resistant and CBA/Ca and SJL mice were susceptible to infection. Further investigation revealed that BALB/c mice were able to prevent proliferation of pneumococci in the lungs and blood, whereas CBA/Ca mice showed no bacterial clearance. Rapidly increasing numbers of bact...

The Om locus was first described in the DDK inbred mouse strain: DDK mice carry a mutation at Om resulting in a parental effect lethality of F(1) embryos. When DDK females are mated with males of other (non-DDK) inbred strains, e.g., BALB/c, they exhibit a low fertility, whereas the reciprocal cross, non-DDK females x DDK males, is fertile (as is the DDK intrastrain cross). The low fertility is...

The optokinetic drum has become an appropriate tool to examine visual properties of mice. We performed baseline measurements using mice of the inbred strains C3H, C57BL/6, BALB/c, JF1, 129 and DBA/2 at the age of 8-15 weeks. Each individual C57BL/6, 129 and JF1 mouse was reliably identified as non-affected in vision by determining head-tracking responses. C3H mice were used as negative control ...

When BALB/cCF mice were crossed reciprocally with 4 other inbred strains, adult brain weights averaged 21.0 mg heavier for hybrid offspring with a BALB mother than those with a BALB father. Reciprocal backcrosses to BALB revealed that this effect was a consequence of the BALB maternal environment, not cytoplasmic or sex chromosomal influences. These findings demonstrate that BALB mice have heav...

There is large variation in the survival of inbred mouse strains infected with Trypanosoma rhodesiense (EATRO 1886). Of those strains that survived for at least 22 days postinfection, female mice were markedly more resistant than male mice. The longer a strain survived, the greater was the difference in survival between male and female mice. Parasite counts were higher in male mice than in fema...

The influence of environmental enrichment on the behaviour of the mouse has been studied in two inbred strains (C57BL and BALB/c). Male mice of each of the two strains were subjected to behavioural tests after being housed for two months either under standard housing conditions or in an enriched environment. The results of the behavioural test indicated that the C57BL mice housed in the enriche...

Female mice of 16 inbred mouse strains were fed an atherogenic diet for 14 weeks and were then evaluated for atherosclerotic lesions in the aorta. Strains C57BL/6, C57BR/cd, C57L, and SM were very susceptible to atherosclerosis, with lesion area/aortic cross-sections in the range of 4500 to 8000 microns 2. Strains C58 and SWR were intermediate in susceptibility, with lesion area/sections in the...

We report that freshly isolated, unstimulated Kupffer cells (KC) from MRL/lpr female mice in short-term culture spontaneously produce high levels of TNF-alpha. TNF production was first detected in KC cultures at age 6 wk and increased with the age of the mice. Moreover, the levels of spontaneous TNF production by KC directly correlated with the age of the MRL/lpr mice. Although TNF production b...