DREAM/calsenilin/KChIP3 modulates strategy selection and estradiol-dependent learning and memory.

Area of Science:

• Neuroscience
• Endocrinology
• Molecular Biology

Background:

• Downstream regulatory element antagonist modulator (DREAM)/calsenilin (C)/K⁺ channel interacting protein 3 (KChIP3) is a Ca²⁺-binding protein highly expressed in the hippocampus.
• KChIP3 inhibits hippocampus-sensitive memory and synaptic plasticity in male mice, but its role in females is less understood.
• Hormonal fluctuations, particularly 17β-estradiol, may influence KChIP3's effects in female hippocampus function.

Purpose of the Study:

• To investigate the interaction between 17β-estradiol and KChIP3 in regulating hippocampus function in female mice.
• To examine the role of estradiol and KChIP3 in learning strategy and memory formation in ovariectomized (OVX) female mice.

Main Methods:

• Ovariectomized wild-type (WT) and KChIP3 knockout (KO) female mice were administered vehicle or 17β-estradiol benzoate.
• Mice underwent behavioral training and testing to assess learning strategy and fear memory formation.
• Electrophysiological recordings (long-term potentiation and paired-pulse depression) were performed on hippocampus slices.

Main Results:

• KChIP3 and estradiol exhibited a time-dependent effect on learning strategy in female mice.
• Fear memory formation was reduced in intact female KO mice compared to WT; OVX affected memory in WT but not KO mice.
• Hippocampus long-term potentiation was enhanced by ovarian hormones in both WT and KO mice, while paired-pulse depression was reduced in KO mice.

Conclusions:

• KChIP3 plays a timing-dependent role in the regulation of learning, memory, and hippocampus plasticity by estradiol.
• These findings highlight a novel interaction between KChIP3 and estrogen in modulating cognitive functions in female mice.