Inhomogeneous Encoding of the Visual Field in the Mouse Retina

Abstract

Stimulus characteristics of the mouse's visual field differ above and below the skyline. Here, we show for the first time that retinal ganglion cells (RGCs), the output neurons of the retina, gradually change their functional properties along the ventral-dorsal axis to allow better representation of the different stimulus characteristics. We conducted two-photon targeted recordings of transient-Offα-RGCs and found that they gradually became more sustained along the ventral-dorsal axis, revealing >5-fold-longer duration responses in the dorsal retina. Using voltage-clamp recordings, pharmacology, and genetic manipulation, we demonstrated that the primary rod pathway underlies this variance. Our findings challenge the current belief that RGCs of the same subtype exhibit the same light responses, regardless of retinal location, and suggest that networks underlying RGC responses may change with retinal location to enable optimized sampling of the visual image.

Retinotopic Separation of Nasal and Temporal Motion Selectivity in the Mouse Superior Colliculus

“…Sensory neurons often display an ordered spatial arrangement that enhances the encoding of specific features on different sides of natural borders in the visual field (for example, [1][2][3]). In central visual areas, one prominent natural border is formed by the confluence of information from the two eyes, the monocular-binocular border [4].…”

Antagonistic center-surround mechanisms for direction selectivity in the retina

“…The retina was extracted and dissected in oxygenated Ames medium (Sigma, St. Louis, MO, USA) under dim red and infrared light. The isolated retina (dorsal part) was then mounted on a 0.22 mm membrane filter (Millipore) with a pre-cut window to allow light to reach the retina and put under a two-photon microscope (Bruker, Billerica, MA, USA) equipped with a Mai-Tai laser (Spectra-physics, Santa Clara, CA, USA) as previously described (Warwick et al, 2018). GFP cells were targeted for recordings with the laser set to 920 nm to minimally activate photoreceptors, and using a 60x water-immersion objective (Olympus, Tokyo, Japan).…”

Visual Circuits: Division of Labor Revealed

“…One obvious question, therefore, is do dorsally located and ventrally located retinal neurons do exactly the same job, even though they tend to analyse different parts of the external world? A new study by Warwick et al [1], reported in this issue of Current Biology, reveals an unexpected division of labor among retinal ganglion cells of the same type depending on retinal location, which may reflect the different behavioral requirements.…”