Baier & Wullimann proposed 3 possible identites for AF-4 in the adult:
Intermediate thalamic nucleus/Nucleus intermedius thalami
Anterior thalamic nucleus/nucleus anterioris thalami
Ventrolateral thalamic nucleus /Nucleus ventrolateralis thalami.
(Baier & Wullimann, 2021).
Schematic showing the approximate location of AF-4 in a 6dpf zebrafish. The optic tract is labelled in the Tg(atoh7:RFP) transgenic line and position of AFs are based on the data from Robles (2014).
AF-4 is preferentially innervated by Retinal Ganglion Cells (RGCs) located in the ventral retina (Robles et al., 2014).
VISUAL BEHAVIOURS ASSOCIATED WITH AF-4
A highly conserved innate behaviour. Larval zebrafish placed in a light-dark choice assay show a significant preference towards light. This light-preference behaviour is mediated by the habenula. The presence and intensity of ambient light is encoded in light responsive habenula neurons that receive input from prethalamic neurons that arborise with ventrally located RGCs at AF-4 (Zhang et al., 2017; Cheng et al.,2017).
Publications
Baier, H., Wullimann, M.F. (2021)
Anatomy and function of retinorecipient arborization fields in zebrafish.
The Journal of comparative neurology. 529(15):3454-3476
Zhang, B.B., Yao, Y.Y., Zhang, H.F., Kawakami, K., Du, J.L. (2017)
Left Habenula Mediates Light-Preference Behavior in Zebrafish via an Asymmetrical Visual Pathway.
Neuron. 93(4):914-928.e4.
Cheng, R.K., Krishnan, S., Lin, Q., Kibat, C., Jesuthasan, S. (2017)
Characterization of a thalamic nucleus mediating habenula responses to changes in ambient illumination. BMC Biology. 15:104.
Robles, E., Laurell, E., Baier, H. (2014)
The Retinal Projectome Reveals Brain-Area-Specific Visual Representations Generated by Ganglion Cell Diversity.
Current biology : CB. 24(18):2085-96.
Burrill JD & Easter Jr SS
Development of the Retinofugal projections.
J Comp Neurology, 2004 pp.1-18.