Cognition, Behavior, and Memory
Author: Juliette López Hanotte | email: julietteloha@gmail.com
Juliette López Hanotte 1°, María Florencia Zappa Villar 1°, Facundo Peralta 1°, Ana Abril Vidal Escobedo 1°, Paula Cecilia Reggiani 1°
1° Instituto de Investigaciones Bioquímicas de La Plata
Male rodents have been the default model organism in neuroscience research, including for the intracerebroventricular (icv) streptozotocin (STZ)-induced AD model. Our objective was to study the effect of icv-STZ in female rats with and without ovaries, and to compare it with STZ-injected males. Male rats were separated into Sham and STZ groups. Half of female rats were ovariectomized (OVX) 14 days before icv-STZ injection and separated into Sham, STZ, OVX, and OVX+STZ groups. Two weeks post injection, we conducted behavioral tests: Marble Burying, Novel Object Recognition, Barnes Maze, and Forced Swimming test. Immunohistochemistry analyses were performed in hippocampus. STZ-males showed overt behavioral deficit, hippocampal damage and neuroinflammation evidenced by reduced immature neurons and an increase in reactive microglia. In females, STZ affected behavioral performance differently depending on the presence of ovaries, with STZ affecting mainly ovariectomized rats. At the morpho-histochemical level, as well 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 increased reactive 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 confirmed the importance of conducting studies comparing sex differences and considering the ovarian status relevance in modulating icv-STZ neurodegenerative effects.