Retinal orientation selectivity
Orientation selective neurons, which respond to edges presented at certain orientations, have been documented in the retina and cortex. However, it is unknown whether cortical orientation selectivity is created de novo in the cortex, or instead derived from processing and integration of orientation-selective signals arriving from the retina, presumably through thalamic and collicular relay neurons. To understand the basis of retinal orientation selectivity and its contribution to cortical orientation selectivity, we study the topographic variation, morphology, physiology, and central projections of orientation-selective retinal ganglion cells.
Polar plot showing response amplitude (normalized to maximum) for eight different directions (N, nasal; D, dorsal; T, temporal; V, ventral). This orientation-selective cell responds best to gratings drifting along the ventral-dorsal axis, corresponding to preference for stimuli that are orientated along the nasal-temporal axis.
Two-photon guided patch-clamp recording
Calcium transients of neurons in an isolated retina in response to sinusoidal contrast gratings drifting in eight directions at 45° intervals.
