Mouse running activity is lowered by Brucella abortus treatment: a potential model to study chronic fatigue

1 Star2 Stars3 Stars4 Stars5 Stars (51 votes, average: 2.90 out of 5)

Chronic fatigue syndrome, which can occur after acute

infection and last for years, is characterized by severe and

persistent fatigue. Others have reported decreases in mouse

running activity following infection and have suggested this

may provide an animal model for studying chronic fatigue.

Voluntary running is a highly motivated activity in mice,

which will often run 5-7 mi/day in our laboratory. Following 2

weeks of acclimation to running wheels with food and water

available ad lib, female BALB/c mice received 0.2-mL tail vein

injections of killed Brucella abortus (BA) or saline vehicle.

Subsequently the effects on voluntary running and grooming

behavior were determined. Injection of BA caused an immediate

large decrease in running and a lack of grooming. Vehicle

injections produced no changes in behavior. After the first

several days of reduced running behavior, levels of running

and grooming slowly returned back to normal over the next 2-4

weeks, with substantial individual differences in the rate of

recovery. The pattern of running during recovery was

intriguing in that BA mice first ran at normal levels just

after the lights went out, but they stopped after only 1-2 h.

As recovery proceeded, they gradually increased the duration

of the running bout during the night. Because this model uses

voluntary exertion and the ability to run for longer periods

of time characterizes recovery, the model may be a good one

for studying the biologic underpinnings of chronic fatigue.

1 Star2 Stars3 Stars4 Stars5 Stars (51 votes, average: 2.90 out of 5)

Leave a Reply