Development of the Early Axon Scaffold in the Rostral Brain of the Small Spotted Cat Shark (Scyliorhinus canicula) Embryo

Figure 4

Developmental series of the S. canicula early axon scaffold. Schematic representation, with colour coding for the neurones and their associated axon tracts that arise in the S. canicula brain. (a) Stage 18: the appearance of the first neurones in the rostral brain. (b) Stage 23: MLF axons were projecting into the rhombencephalon, and the nTPOC, DTmesV, and DVDT have appeared. (c) Stage 25: the early axon scaffold appeared to be well established, with the addition of the AC, SOT, THC, TPC, VC, and LLF. AC: anterior commissure; ADt: anterior dorsal telencephalic neurones; di: diencephalon; DTmesV: descending tract of the mesencephalic nucleus of the trigeminal nerve; ep: epiphysis; LLF: lateral longitudinal fascicle; nMLF: nucleus of the medial longitudinal fascicle; nTPOC: nucleus of the tract of the postoptic commissure; mes: mesencephalon; MLF: medial longitudinal fascicle; MTT: mammillotegmental tract; op: olfactory pit; os: optic stalk; PC: posterior commissure; rh: rhombencephalon; SOT: supraoptic tract; tel: telencephalon; THC: tract of the habenular commissure; TPC: tract of the posterior commissure; TPOC: tract of the postoptic commissure; VC: ventral commissure.

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