Presentation description

Kirrel3 is a synaptic cell adhesion protein necessary for forming a specific type of synapse in the hippocampus, a brain region important for learning and memory. Kirrel3 is expressed on both sides of the synapse and mediates cell adhesion likely by holding the synaptic membranes together. Previously the Megan William's lab found that germline Kirrel3 knock-out mice are missing these specific synapses in the hippocampus. Interestingly, mice expressing Kirrel3 during development continue to express it after synapse formation. However, it is unknown if Kirrel3 is still needed once these synapses are formed. To test this, I injected a virus to remove Kirrel3 in conditional adult mice after synapse formation. I then assessed synapse density and function by analyzing the activity of downstream neurons called CA3 pyramidal neurons. My results showed a significant increase in CA3 neuron activity in conditional Kirrel3-injected adult mice compared to wild-type injected adult mice that continued to express Kirrel3. This suggests that Kirrel3 is needed to maintain this specific synapse. However, an in situ staining showed signaling for Kirrel3 mRNA, indicating that bits of Kirrel3 continued to be transcribed. Therefore, further experiments are needed to remove Kirrel3 completely. Continuing this investigation of Kirrel3 in adult mice will bring us closer to understanding the mechanical role of Kirrel3 in synaptic formation and neuronal connectivity. Moreover, understanding the function of Kirrel3 may be clinically beneficial as variations in Kirrel3 are associated with neurodevelopmental disorders like autism and learning disabilities.