The Lamina is a neuropil that resides in the optic lobe of the early visual system of the fruit fly. Its neural circuit consists of some 700~800 cartridges. A cartridge is an atomic neural circuit abstraction whose I/O behavior can be studied in isolation. The anatomy of the neurons, neurotransmitter types and connectivity patterns of the neurons in the cartridge are briefly reviewed. A circuit-level model of a cartridge suitable for implementation on a GPU platform is presented in detail. Cartridge interconnects create neural circuits with different I/O characteristics. A number of cartridge composition rules for building neural circuits with different spatial I/O characteristics are discussed. We present a model neural circuit for initial functional evaluations and scaling of the Lamina and its interconnection with the Medulla. Implementation considerations of the Lamina neural circuit are discussed.

Additional documentation about Neurokernel project are available at http://neurokernel.github.io