The rabbit and the cat: A comparison of some features of response properties of single cells in the primary visual cortex

Abstract

Receptive field characteristics of single cells in primary visual cortex of rabbit were studied. Seventy-two percent of cells were found to be orientation selective, and the remainder had concentric, uniform, movement selective or pure direction selective receptive fields. Single cells were also recorded from primary visual cortex of cat to permit a comparison of visual cortical organization in cats and rabbits. Laminar organization of receptive field types was observed in rabbits which was similar in most respects to that described in the cat. Although the major categories of orientation selective cells (simple, complex, hypercomplex) were similar for both cat and rabbit, many differences emerged: (I) tuning of orientation selectivity was narrower in cats than in rabbits; (II) units which preferred oblique orientations were less frequently represented in rabbits than in cats; (III) orientation preferences appeared to be arranged in clusters in rabbit cortex; in rabbits we found no evidence of the columnar organization of orientation selectivity which characterizes cat visual cortex. A comparison of our data with those previously reported for mouse, rat, hamster and opossum visual cortex suggest that mammals in which a significant proportion of visual cortical cells are not orientation selective have in common certain patterns of cortical organization involving a less precise and less specilized representation of stimulus orientation.

Orientation Selectivity without Orientation Maps in Visual Cortex of a Highly Visual Mammal

“…Some models of V1 posit that orientation selectivity and selectivity that is invariant to stimulus contrast arise from local synaptic connections, with neurons receiving a large excitatory input from nearby cells with similar orientation preferences and broadly tuned inhibition (BenYishai et al, 1995;Somers et al, 1995). However, rodents and lagomorphs do show robust orientation tuning in V1 (Murphy and Berman, 1979;Girman et al, 1999), despite lacking an orientation map, and we have shown that orientation tuning in squirrels is contrast invariant. In addition, V1 is essential for the perception of orientation in squirrels, because V1 lesions in ground squirrels impair orientation discrimination (Kicliter et al, 1977).…”

“…In primary visual cortex (V1), neurons respond preferentially to images of bars or edges of a particular orientation, and, in V1 of primates (Hubel et al, 1978;Blasdel and Salama, 1986), carnivores (Hubel and Wiesel, 1963;Grinvald et al, 1986;McConnell and LeVay, 1986), ungulates (Clarke et al, 1976), and tree shrews (Humphrey and Norton, 1980;Bosking et al, 1997), these orientation-selective cells are arranged in a semiregular, smoothly varying map with local discontinuities. Curiously, whereas electrophysiological and imaging studies of many rodents, including mice (Metin et al, 1988;Schuett et a., 2002), rats (Girman et al, 1999), hamsters (Tiao and Blakemore, 1976), and a lagomorph, the rabbit (Murphy and Berman, 1979), have identified orientation-selective neurons in these species, no orderly orientation map has been found. Understanding why these animals do not have orientation maps may shed light on functional roles and developmental mechanisms of orderly maps in mammalian sensory cortex.…”

Monocular Cells Without Ocular Dominance Columns

“…However, there is little evidence for orientation columns in mice, rats, hamsters, and rabbits (Chow et al 1971;Dräger 1975;Girman et al 1999;Murphy and Berman 1979;Ohki et al 2005;Shaw et al 1975;Tiao and Blakemore 1976). Recently, Van Hooser et al (2005) have shown that orientation columns are also absent in the squirrel, an animal with well-oriented cells and a relatively large V1 surface area.…”

Dominant Vertical Orientation Processing without Clustered Maps: Early Visual Brain Dynamics Imaged with Voltage-Sensitive Dye in the Pigeon Visual Wulst

“…In birds, the maximal overlap is 40 -50°(kestrels) versus 140 -150°(primates) in mammals. a Orientation maps: human (Yacoub et al, 2008); macaque (Blasdel and Salama, 1986); owl monkey (Xu et al, 2004); marmoset (McLoughlin and Schiessl, 2006); cat (Bonhoeffer and Grinvald, 1991); ferret (Weliky and Katz, 1994); tree shrew (Bosking et al, 1997); squirrel (Van Hooser et al, 2005); rat (Ohki et al, 2005); mouse, electrophysiology (Dräger, 1975); rabbit, electrophysiology (Bousfield, 1977;Murphy and Berman, 1979); barn owl (Liu and Pettigrew, 2003). b Binocular overlap and orbit convergence.…”