Abstract
Purpose: Human albinos have a low visual acuity. This is partially due to the presence of spontaneous erroneous eye movements called pendular nystagmus. This nystagmus is present in other albino vertebrates and has been hypothesized to be caused by aberrant wiring of retinal ganglion axons to the nucleus of the optic tract (NOT), a part of the accessory optic system involved in the optokinetic response to visual motion. The NOT in pigmented rodents is preferentially responsive to ipsiversive motion (i.e., motion in the contralateral visual field in the temporonasal direction). We compared the response to visual motion in the NOT of albino and pigmented mice to understand if motion coding and preference are impaired in the NOT of albino mice. Methods: We recorded neuronal spiking activity with Neuropixels probes in the visual cortex and NOT in C57BL/6JRj mice (pigmented) and DBA/1JRj mice with oculocutaneous albinism (albino). Results: We found that in pigmented mice, NOT is retinotopically organized, and neurons are direction tuned, whereas in albino mice, neuronal tuning is severely impaired. Neurons in the NOT of albino mice do not have a preference for ipsiversive movement. In contrast, neuronal tuning in visual cortex was preserved in albino mice and did not differ significantly from the tuning in pigmented mice. Conclusions: We propose that excessive interhemispheric crossing of retinal projections in albinos may cause the disrupted left/right direction encoding we found in NOT. This, in turn, impairs the normal horizontal optokinetic reflex and leads to pendular albino nystagmus.
Original language | English |
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Article number | 9 |
Pages (from-to) | 1-12 |
Number of pages | 12 |
Journal | Investigative ophthalmology & visual science |
Volume | 64 |
Issue number | 11 |
Early online date | 7 Aug 2023 |
DOIs | |
Publication status | Published - Aug 2023 |
Funding
Funding from Fund Van Hessen-Israels (JSM) by the Stichting Vrienden van het Herseninstituut awarded to JAH and by the Royal Netherlands Academy of Arts and Sciences (KNAW).
Funders | Funder number |
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Stichting Vrienden van het Herseninstituut | |
Koninklijke Nederlandse Akademie van Wetenschappen |