Streptozotocin‐induced sporadic Alzheimer's disease: Behavioral effects in female rats

Sporadic Alzheimer's disease (SAD) is the main cause of dementia worldwide with no effective therapy. This multifactorial pathology is characterized by behavioral and cognitive impairment. Despite the fact that women show an increased risk of SAD, female animals are often excluded from basic research. In this line, an intracerebroventricular infusion of streptozotocin (icv-STZ) is commonly employed to generate SAD model in male animals. However, whether sex differences exist in the icv-STZ model remains unknown. Our objective was to study the female brain changes in rats with experimental SAD.Animals were submitted into 4 experimental groups (female Sprague Dawley rats, N=8): Sham, STZ, OVX and OVX+STZ. OVX and OVX+STZ groups were ovariectomized and, 14 days later, STZ and OVX+STZ groups were injected with 3 mg/kg icv-STZ. Body weight of all rats was registered along the experiment every week. During the last two weeks until the end of the study (day 30 post icv-STZ), we assessed several behavioural tests: species-typical behaviour (Marble Burying), object recognition memory (Novel Object Recognition), spatial learning and memory (Barnes Maze), and depressive-like behaviour (Forced Swim Test).Our preliminary results show that STZ affected behavioral performance differently in the SAD model depending on the ovarian steroid levels of female rats.Overall, we conclude that the potential impact of sex differences on brain function is a relevant issue and it should be considered in future SAD research.