By making knockout mice, Frederique Varoqueaux at the Max Planck Institute of Experimental Medicine in Germany and his colleagues revealed that neuroligin, a cell adhesion molecule, may not be essential for synaptogenesis.
"Neuroligins have been proposed to be important to initiate synapses in the mammalian brain. All the experiments that have been done to test this hypothesis have been in cultured neurons... but it's never been tested by just removing the gene from the animal.
"When you take out the three dominant isoforms of neuroligins from the mouse genome, there doesn't seem to be a very big effect on the number of synapses in native tissues and cultured networks. One possibility is that when you have mixed populations of cells, the ones that don't have ...
