Differential responsiveness of cells in the visual zones of the cat's LP-pulvinar complex to visual stimuli.
Multiple visual field representations are contained within the feline LP-pulvinar complex; regions differentiated by their afferent and efferent connectivity patterns as the striate-, tecto- and retino-recipient zones. Cell responses from these visuotopic zones were investigated in immobilized cats under N2O/O2 supplemented with pentobarbitone or Althesin, using spot, bar and textured stimuli. Response fields recorded within the LP-pulvinar complex were classified as diffuse, concentric, movement-, direction- or orientation-sensitive. Concentric receptive fields were further classified as sustained (X), transient (Y) or tonic/phasic W-cells. Direction- and movement-sensitive cells predominated in the striate- and tecto-recipient zones, respectively. Motion of noise fields, or noise bars against an identical stationary noise background elicited vigorous responses from cells in the striate zone, many showing a preference for noise stimuli. In contrast, cells from the tectal zone and other divisions of the LP-pulvinar complex were insensitive to noise. The retino-recipient zone at the lateral margin of the pulvinar nucleus was characterized by cells with concentric receptive fields, the majority exhibiting properties similar to W-cells in the LGNd. The evidence supports the notion of functional subdivision within the LP-pulvinar complex corresponding to the visuotopically organized regions defined by their connectivity patterns. Consideration of the retino-recipient zone as an extension of the LGNd-MIN complex is discussed.
D000818:Animals; D001931:Brain Mapping; D002415:Cats; D004193:Discrimination Learning / Q000502:physiology; D005071:Evoked Potentials; D005829:Geniculate Bodies / Q000502:physiology; D009474:Neurons / Q000502:physiology; D012160:Retina / Q000502:physiology; D013477:Superior Colliculi / Q000502:physiology; D009435:Synaptic Transmission; D013787:Thalamic Nuclei / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*