Protocadherin Alpha, Beta, and Gamma are families of proteins that play crucial roles in cell adhesion and communication in the nervous system. They are part of the cadherin superfamily and are primarily expressed in the brain, where they help establish and maintain synaptic connections between neurons. These proteins are encoded by a large number of genes, allowing for a diverse range of interactions. Protocadherins contribute to the formation of neural networks and are involved in processes such as neurodevelopment and synaptic plasticity, which are essential for learning and memory.