Acute cardiac damage can be induced by isoproterenol injections in animals. The associated
inflammatory response could be reflected in the brain as neuroinflammation, with potential
consequences for brain function and behavior. Although cardiac responses are reported
age and sex-related, for neuroinflammation and brain function this is virtually unknown.
Therefore, cardiac damage and its consequences for neuroinflammation, brain function
and behavior were compared in aged male and female rats. Wistar rats of 24 months
of age were treated with isoproterenol (ISO, twice s.c.) or saline. Four weeks after
injections, exploratory behavior and short-term memory were tested. Then, rats were
sacrificed. Hearts were collected to measure cardiac damage. Brain tissue was collected
to obtain measures of neuroinflammation and brain function. In male-, but not in female
rats, ISO induced significant cardiac damage. Accordingly, mortality was higher in
males than in females. Baseline hippocampal microglia activity was lower in females,
while ISO induced neuroinflammation in both sexes, Hippocampal brain-derived neurotrophic
factor expression appeared lower in females, without effects of ISO. In the open field
test, ISO-treated males, but not females, displayed anxiety-like behavior. No effects
of ISO were observed on short-term memory in either sex. In conclusion, sex dimorphism
in effects of ISO was observed for cardiac damage and open field behavior. However,
these effects could not be related to differences in hippocampal neuroinflammation
or neuronal function.
