| Description |
Alterations in the gene Kirrel3 are repeatedly associated with intellectual disability and autism. Kirrel3 regulates synapse formation in C. elegans but the role of Kirrel3 in synapse formation in the mammalian brain is unknown. In mice, Kirrel3 is expressed in specific cell types throughout the brain which includes neurons in the hippocampus, a brain region critically required for learning and memory. In the hippocampus, Kirrel3 is expressed by DG neurons and a subset of GABAergic interneurons in the CA3 region. Interestingly, these neurons are physically linked, together with CA3 pyramidal neurons, in a giant structure called the mossy fiber (MF) synapse. Here, I investigated the role of Kirrel3 in the formation of MF synapses in vivo by lipophilic DiI tracing of axons and single neuron microinjection of dendrites. In collaboration with other members of the Williams lab, we discovered that the loss of Kirrel3 causes synaptic defects between DG and GABA neurons while synapses between DG and CA3 neurons are normal. Together, these results suggest that Kirrel3 plays an important role in specifically regulating the DG-GABA component of MF synapses in mammalian hippocampus. |
