BEHAVIORAL AND HIPPOCAMPAL IMPAIRMENT IN INTRACEREBROVENTRICULAR STREPTOZOTOCIN-INJECTED FEMALE AND MALE RATS

JULIETTE LÓPEZ HANOTTE; MARÍA FLORENCIA ZAPPA VILLAR; FACUNDO PERALTA; ANA ABRIL VIDAL ESCOBEDO; PAULA CECILIA REGGIANI

Buenos Aires

Congreso; XXXVII SAN Annual Congress; 2022

Sociedad Argentina de Investigación en Neurociencia (SAN)

Malerodents have been the default model organism in neuroscience research,including for the intracerebroventricular (icv) streptozotocin (STZ)-induced ADmodel. Our objective was to study the effect of icv-STZ in female rats with andwithout ovaries, and to compare it with STZ-injected males. Male rats wereseparated into Sham and STZ groups. Half of female rats were ovariectomized(OVX) 14 days before icv-STZ injection and separated into Sham, STZ, OVX, andOVX+STZ groups. Two weeks post injection, we conducted behavioral tests: MarbleBurying, Novel Object Recognition, Barnes Maze, and Forced Swimming test. Immunohistochemistryanalyses were performed in hippocampus. STZ-males showed overt behavioraldeficit, hippocampal damage and neuroinflammation evidenced by reduced immatureneurons and an increase in reactive microglia. In females, STZ affectedbehavioral performance differently depending on the presence of ovaries, withSTZ affecting mainly ovariectomized rats. At the morpho-histochemical level, aswell as males, STZ reduced the number of immature neurons in the Dentate Gyrus(DG), and this loss was higher in OVX rats. Regarding microglia, STZ increasedreactive cells but also OVX+STZ group showed an increase in the total cell number.Unlike males, STZ increased GFAP immunoreactive area in the DG. We confirmedthe importance of conducting studies comparing sex differences and consideringthe ovarian status relevance in modulating icv-STZ neurodegenerative effects.