Abstract
BackgroundEstrogen deficiency is linked to changes in several physiological processes, but the extent to which it associates with cognitive changes in menopause context is controversial.RationaleWe evaluated the impact of ovariectomy on memory processes and normal exploratory behavior in Wistar rats.MethodsYoung adult rats (4–6 months) were either ovariectomized (OVX group) (N = 10), sham operated (N = 10), or untouched (naïve controls) (N = 8). Afterwards, they were monitored for 12 weeks during which their cognitive functions were evaluated at first week (S1), second (S2), every 3 weeks (S5, S8) and then at week 12 (S12) using: (i) object recognition test to evaluate the short-term and long-term non-spatial memory; (ii) the object placement test to assess the spatial memory; and (iii) normal exploratory behavior components like locomotor and vertical activities in an open field arena.ResultsMarked changes in ovariectomized rats were observed in long-term non-spatial memory (~ 40% change vs. naïve and sham, P < 0.001) and spatial memory (~ 30% change, P < 0.05) from S2. Instead, from S5 the exploratory behavior was affected, with decreases in line crossing and rearing episode numbers (~ 40% change, P < 0.01), and in the time spent in the center of open field arena (~ 60% change, P < 0.01).ConclusionsOur findings support the involvement of sex hormones in cognitive functions in female rats and suggest that controversy on the importance of cognitive affections in menopause context may emerge from differences between short-term and long-term memory processes.
Highlights
Estrogen deficiency is linked to changes in several physiological processes, but the extent to which it associates with cognitive changes in menopause context is controversial.Rationale: We evaluated the impact of ovariectomy on memory processes and normal exploratory behavior in Wistar rats
There is controversy on the specific features with translational potential in this model, which contributes to disagreements on the importance of cognitive affections in menopause context [7]
Object recognition Short‐term memory Figure 2a shows the effects of ovariectomy on shortterm object recognition ability in rats, throughout the first 12 weeks following surgery
Summary
Estrogen deficiency is linked to changes in several physiological processes, but the extent to which it associates with cognitive changes in menopause context is controversial.Rationale: We evaluated the impact of ovariectomy on memory processes and normal exploratory behavior in Wistar rats. Djiogue et al Behav Brain Funct (2018) 14:14 used to induce a menopause-like status in laboratory rodents It results in definitive cessation of ovarian hormones’ production [6], and mimics some features of human menopause. Studies in ovariectomized animals showed significant alterations in the structure and function of hippocampal and cortical circuits accompanied by poor performance in several cognitive tasks [9,10,11,12]. These observations were confirmed in humans, as estrogen therapy improved performances in cognitive tasks, verbal memory, and executive functions of perimenopausal women [13]. It was hypothesized that such controversy may emergence from differences in experimental protocols, in time intervals between ovariectomy and object recognition testing [9, 15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
