Membrane receptors mediate the rapid facilitation of short-term memory by estradiol in the dorsal hippocampus of female mice

Abstract

Estrogens play a key role in learning and memory via delayed genomic and early-onset rapid mechanisms. Systemic treatment with 17β-estradiol (E2) rapidly facilitates object recognition, social recognition and object placement short-term memory in ovariectomized female mice within a timescale of only 40 min following administration. The dorsal hippocampus is one critical site of rapid estrogenic effects. Estrogen receptors (ER) are located in the cell nucleus, cytoplasm and membrane. Membrane ERs alone can mediate the rapid facilitation of long-term memory consolidation by estrogens. This study determined the role of membrane ERs in the rapid effects of 17-β estradiol (E2) on short-term memory within the dorsal hippocampus of ovariectomized mice. We infused E2 conjugated to bovine serum albumin (BSA-E2) that prevents it from crossing the cell membrane and found that the rapid facilitation by E2 of short-term memory in the social recognition, object recognition and object placement tasks is mediated by membrane ERs, independently of intracellular receptors.

Keywords: BSA-E2; ER; object placement; object recognition; social recognition.