Testosterone deprivation reshapes the behavioral response to STZ-ICV, producing selective behavioral changes while

preserving—and potentially enhancing—novel object recognition.

Intracerebroventricular streptozotocin (STZ-icv) is a widely used model of neurodegeneration and cognitive impairment associated with hippocampal dysfunction. However, the influence of testosterone on the behavioral effects induced by STZ-icv remains unclear. Castrated male rats provide a useful model to evaluate the contribution of testosterone to STZ-induced alterations.

Animals and Experimental Groups. Male Sprague-Dawley rats (3 months old) n =7  animals/group: Sham: aCSF-icv, ORQ: Bilateral orchiectomy + aCSF-icv, ORQ+STZ: Bilateral orchiectomy + STZ-icv

ORQ+STZ rats showed significantly fewer buried marbles compared with Sham animals (p < 0.05).

ORQ+STZ rats spent significantly more time exploring the novel object than ORQ rats (p < 0.05).

No differences in latency or exploratory parameters. Spatial memory remained preserved.

ORQ+STZ rats exhibited higher floating behavior than ORQ rats; however, this difference did not reach statistical significance.

STZ-ICV administration in castrated male rats induced selective behavioral changes while preserving cognitive performance. The increased exploration of the novel object suggests that testosterone deprivation modifies the classical behavioral phenotype induced by STZ-ICV, highlighting hormonal status as an important determinant of vulnerability in experimental models of neurodegeneration.