Functional asymmetries in visual pathways carrying S-cone signals in macaque.
In the lateral geniculate nucleus of macaque, we recorded from neurons with substantial input from S-cones and found that, on several important dimensions, the properties of neurons that receive inhibitory input from S-cones ("S-") are quite unlike those of neurons that receive excitatory input from S-cones ("S+"). First, the organization of chromatic inputs differs substantially: in S+ cells, S-cone signals were usually opposed by those of L- and M-cones; in S- cells, signals from L-cones were usually opposed to those of S- and M-cones. Second, to pure S-cone modulation, S+ cells are twice as sensitive as S- cells, but S- cells were much more susceptible to contrast adaptation. Third, in S- cells but not S+ cells, the spatial frequency resolution for achromatic modulation was often greater, the tuning curve and more bandpass, than that for S-cone modulation. Along the dimensions on which we measured, the properties of the S+ cells were relatively tightly clustered, suggesting a homogenous class. Although the chromatic properties of S- cells are heterogeneous, the distribution of their tuning along other stimulus dimensions does not suggest multiple subtypes.
Tailby
Chris
C
Center for Neural Science, New York University, New York, New York 10003, USA. ctailby@unimelb.edu.au
Solomon
Samuel G
SG
Lennie
Peter
P
D000222:Adaptation, Physiological; D000818:Animals; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology; D004594:Electrophysiology; D005829:Geniculate Bodies / Q000166:cytology / Q000502:physiology*; D008252:Macaca fascicularis / Q000502:physiology*; D008297:Male; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000502:physiology; D010775:Photic Stimulation; D011930:Reaction Time; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology*