Retinal Input to Macaque Superior Colliculus Derives from Branching Axons Projecting to the Lateral Geniculate Nucleus.

The superior colliculus receives a direct projection from retinal ganglion cells. In primates, it remains unknown if the same ganglion cells also supply the lateral geniculate nucleus. To address this issue, a double-label experiment was performed in two male macaques.

Permanent transduction of retinal ganglion cells by rAAV2-retro.

Adeno-associated virus (AAV) is widely used as a vector for delivery of gene therapy. Long term therapeutic benefit depends on perpetual expression of the wild-type gene after transduction of host cells by AAV. To address this issue in a mass population of identified single cells, 4 rats received an injection of a 1:1 mixture of rAAV2-retro-hSyn-EGFP and rAAV2-retro-hSyn-mCherry into each superior colliculus.

Quotidian Profile of Vergence Angle in Ambulatory Subjects Monitored With Wearable Eye Tracking Glasses.

Purpose: Wearable eye trackers record gaze position as ambulatory subjects navigate their environment. Tobii Pro Glasses 3 were tested to assess their accuracy and precision in the measurement of vergence angle.

Methods: Four subjects wore the eye tracking glasses, with their head stabilized, while fixating at a series of distances corresponding to vergence demands of: 0.

Decussating axons segregate within the anterior core of the primate optic chiasm.

Background: The axons of ganglion cells in the nasal retina decussate at the optic chiasm. It is unclear why tumours cause more injury to crossing nasal fibres, thereby giving rise to temporal visual field loss in each eye. To address this issue, the course of fibres through the optic chiasm was examined following injection of a different fluorescent tracer into each eye of a monkey.

Fundus imaging of retinal ganglion cells transduced by retrograde transport of rAAV2-retro.

Access of adeno-associated virus (AAV) to ganglion cells following intravitreal injection for gene therapy is impeded by the internal limiting membrane of the retina. As an alternative, one could transduce ganglion cells via retrograde transport after virus injection into a retinal target nucleus. It is unknown if recombinant AAV2-retro (rAAV2-retro), a variant of AAV2 developed specifically for retrograde transport, is capable of transducing retinal ganglion cells.

Columnar and Laminar Segregation of Retinal Input to the Primate Superior Colliculus Revealed by Anterograde Tracer Injection Into Each Eye.

Purpose: After the lateral geniculate nucleus, the superior colliculus is the richest target of retinal projections in primates. Hubel et al. used tritium autoradiography to show that axon terminals emanating from one eye form irregular columns in the stratum griseum superficiale.

Interocular suppression in primary visual cortex in strabismus: impact of staggering the presentation of stimuli to the eyes.

Diplopia (double vision) in strabismus is prevented by suppression of the image emanating from one eye. In a recent study conducted in two macaques raised with exotropia (an outward ocular deviation) but having normal acuity in each eye, simultaneous display of stimuli to each eye did not induce suppression in V1 neurons. Puzzled by this negative result, we have modified our protocol to display stimuli in a staggered sequence, rather than simultaneously.