Synapses are represented as separate pre- and postsynaptic components, located at specific locations on segments. Each segment may have any number of anatomical synapses of any type, and can identify which other segments to which it is pre- or postsynaptic. A synapse is allowed to form when an axon from one group grows sufficiently close to an element of a target group. The “type” of synapse can be a property of both groups. Synaptic triads or serial synapses may result from these primitives. Synapses play an extremely important functional role in shaping real brains, but currently simulated synapses are almost purely anatomical, with few maturational and physiological consequences. Synapse loss is a prominent and consistent finding in postmortem tissue samples from patients diagnosed with AD.