The establishment of accurate synaptic transmission underlies neural network processing and nervous system function. The organized deployment of specialized synaptic machinery is a key cellular process that shapes the synapse and its transmission properties, yet the molecular mechanisms involved in assembling the synaptic apparatus are largely unknown. This work has focused on the role of Neuroligins, a family of postsynaptic adhesion molecules, in mediating differentiation of inhibitory, GABAergic and glycinergic, postsynapses.