Fig. 3

Fig. 3 Representation of visual motion tuning in the dIPN is organized in stripes.

a Illustration of the zebrafish brain, horizontal (left) and sagittal (right) views. The IPN and its afferent structures are highlighted (habenula is shown in purple, IPN is shown in light blue, aHB is shown in gold) dashed square and line indicate the dIPN (field of view in following plots). b Illustration of heading direction representation in the dIPN (based on⁵). Left, illustration of the morphology of three HDNs and their projections in the dIPN: each HDN has a single neurite that goes ventrally and splits into an ipsilateral dendrite and a contralateral axon. Right, illustration of the activity of HDN neuropil in the IPN when the fish is facing different directions. When an HDN is active, both its axon and dendrite are active in the dIPN (c) Illustration of the IPN and its different components as expected in the pan-neuronal line: local IPN cells, neuropil from the aHB and habenula axons. d Left, median tuning map of the dIPN in the Tg(elavl3:GCaMP6s) line labeling the cytosol pan-neuronally (n = 4). Each pixel is colored according to the direction it is tuned to. Right, tuning maps of three example fish. e Illustration of habenula input to the dIPN. Axons from the left habenula enter the IPN and then wrap around it. f Left, median tuning map of the dIPN in the Tg(16715:Gal4) line labeling only habenula axons (n = 12). Right, tuning maps of three example fish. g Illustration of IPN cells and their neuropil. h Left, median tuning map of the dIPN in the Tg(s1168t:Gal4) line labeling IPN cells and neuropil (n = 15). Right, tuning maps of three example fish. i Illustration of GABAergic elements in the dIPN, which consists mostly from sparse expression in the IPN itself with additional neuropil that mostly originates in the aHB. j Left, median tuning map of the dIPN in the Tg(gad1b:Gal4) fish (n = 21). Right, tuning maps of three example fish. Arrows indicate neuropil stripes that are tuned to the same direction on both sides of the dIPN.