Fragile X Syndrome

Fragile X Syndrome (FXS) is a neurodevelopmental disorder caused by the loss of expression of a protein called fragile X mental retardation protein (FMRP). This protein is an important regulator of protein translation and a lack of FMRP expression can lead to learning impairments and anxiety in new and stressful social situations. In the Christie Lab, we focus on a specific structure of the brain, the hippocampus, which is important for learning, memory and emotion. Using transgenic mouse models, we investigate the effects of fragile x syndrome on processes like neurogenesis: the formation of new cells including neurons.

Modeling FXS

In order to study fragile x syndrome and its effects on the hippocampus, we employ a transgenic mouse model. The knockout mice lack the FMR1 gene which in turn leads to loss of production of FMRP. The absence of this protein in mice causes learning and memory deficits and alters anxiety and depression-related behaviours. We can study these changes that occur by studying specific behaviours and molecular processes.


To study how neural communication is altered in our transgenic mice, the Christie laboratory employs both in vitro (acute slice) and in vivo (whole animal) whole cell and field electrophysiology techniques. Additionally, we use immunohistochemical studies to examine neuronal structure, neurogenesis and other markers of brain health as well as molecular techniques such as Western blotting to study specific changes in protein levels. The lab also employs a wide array of behavioural tests: deficits in learning and memory are studied in tasks such as the Morris water maze while emotions such as anxiety and depression are assessed using the open field and the elevated plus maze. 

Want to learn more?

Check out our latest publications to learn more about the work being done in the Christie laboratory related to FXS.