Memory impairment is associated with the loss of regular oestrous cycle and plasma oestradiol levels in an activity-based anorexia animal model

Abstract

Objectives: Patients with anorexia nervosa (AN) suffer from neuropsychological deficits including memory impairments. Memory partially depends on 17β-oestradiol (E2), which is reduced in patients with AN. We assessed whether memory functions correlate with E2 plasma levels in the activity-based anorexia (ABA) rat model. Methods: Nine 4-week-old female Wistar rats were sacrificed directly after weight loss of 20–25% (acute starvation), whereas 17 animals had additional 2-week weight-holding (chronic starvation). E2 serum levels and novel object recognition tasks were tested before and after starvation and compared with 21 normally fed controls. Results: Starvation disrupted menstrual cycle and impaired memory function, which became statistically significant in the chronic state (oestrous cycle (P < 0.001), E2 levels (P = 0.011) and object recognition memory (P = 0.042) compared to controls). E2 reduction also correlated with the loss of memory in the chronic condition (r = 0.633, P = 0.020). Conclusions: Our results demonstrate that starvation reduces the E2 levels which are associated with memory deficits in ABA rats. These effects might explain reduced memory capacity in patients with AN as a consequence of E2 deficiency and the potentially limited effectiveness of psychotherapeutic interventions in the starved state. Future studies should examine whether E2 substitution could prevent cognitive deficits and aid in earlier readiness for therapy.

Key words:

• Adolescent
• anorexia nervosa
• behaviour
• eating disorders
• neuropsychiatry

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Erratum

Acknowledgments

The present work was performed in (partial) fulfilment of the requirements for obtaining the degree “Dr. med.”/”Dr. med. dent.”/”Dr. rer. biol. hum.” It was edited by the American Journal Experts. We would like to acknowledge the support of Mareike Schulz, Pascal Paschenda and Kira Scherer in the institute for laboratory animal science as well as Mac McLaughlin, Cheryl D. Conrad and Victoria Luine for their methodic help in establishing object recognition at our laboratory. This research was funded by the University Hospital Aachen, RWTH Aachen University, (START 108/12).

Statement of interest

None to declare.