The lamina is the most peripheral
neuropil of the
insect visual system. There are twelve distinct neuron classes in the lamina: the
lamina monopolar cells L1-L5, two
GABA
GABA (gamma-aminobutyric acid, γ-aminobutyric acid) is the chief inhibitory neurotransmitter in the developmentally mature mammalian central nervous system. Its principal role is reducing neuronal excitability throughout the nervous system.
GA ...
ergic feedback neurons (C2 and C3), two wide-field feedback neurons (Lawf1 and Lawf2), lamina intrinsic amacrine neurons (Lai) and the T1 basket cell. The outer
photoreceptors, R1-R6, terminate in the lamina, where they form tetrad synapses with L1, L2, L3, and Lai.
The lamina was the first portion of the nervous system of Drosophila to be reconstructed, thus starting the field of
Drosophila connectomics. However the methods used were largely manual and further progress awaited more automated techniques.
References
Insect anatomy
Visual perception
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