What is it about?

Social situations are highly dynamic and rich in detail. Social species, therefore, need to be able to rapidly adapt within these situations in order to behave appropriately. In previous work, the sex hormone estradiol was found in female mice to rapidly improve the memory for other mice they had encountered. Alongside this, increases in dendritic spines – the anatomical regions of neurons in the brain that form synapses with other neurons and allow for communication within the brain – have been observed. However, these spines may or may not form synapses and lead to memory formation. In the present study, Sheppard and colleagues explored whether estradiol increases these neuronal connections to improve short-term social memory, as well as some of the underlying molecular mechanisms. The results showed that estradiol increased synapse number in mice that performed a short-term social memory task; however, in mice that did not perform the task, there was a decrease in synapse number. This suggests dynamic "use it or lose it" effects of estradiol are involved in their rapid effects on social memory.

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Why is it important?

At a party, it is important to remember who is whom for the duration of the party. But the next day or week, that information might not be necessary. This paper demonstrates novel, dynamic actions of estradiol on the brain in service of short-term social memory. This "use it or lose it" mechanism is highly adaptive and creates an "optimal" state for memory. Estradiol appears to fine-tune the number of neural connections in favour of memory. This paper also highlights the importance of considering what behaviour tests might do with regards to underlying mechanisms in behavioural experiments. These tests in and of themselves may have effects on the brain, for example, and should be considered when designing experiments.


This paper was an important part of my grad school work. It was my first international collaboration and allowed me to experience #teamscience firsthand. This type of collaborative effort is now highly important to me; harnessing the strengths of different labs, groups, and individuals is so important in modern science.

Paul Sheppard
Western University

Read the Original

This page is a summary of: Social memory in female mice is rapidly modulated by 17β-estradiol through ERK and Akt modulation of synapse formation, Proceedings of the National Academy of Sciences, July 2023, Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.2300191120.
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