Parallel development of orientation maps and spatial frequency selectivity in cat visual cortex

Abstract

In an early stage of the postnatal development of cats, orientation maps mature and spatial frequency selectivity is consolidated. To investigate the time course of orientation map maturation associated with the consolidation of spatial frequency selectivity, we performed optical imaging of intrinsic signals in areas 17 and 18 of cats under the stimulation of drifting square-wave gratings with different orientations and spatial frequencies. First, orientation maps for lower spatial frequencies emerged in the entire part of the lateral gyrus, which includes areas 17 and 18, and then these orientation maps in the posterior part of the lateral gyrus disappeared as orientation maps for higher spatial frequencies matured. Independent of age, an anteroposterior gradient of response strengths from lower to higher spatial frequencies was observed. This indicates that the regional distribution of spatial frequencies is innately determined. The size of iso-orientation domains tended to decrease as the stimulus spatial frequency increased at every age examined. In contrast, orientation representation bias changed with age. In cats younger than 3 months, the cardinal (vertical and horizontal) orientations were represented predominantly over the oblique orientations. However, in young adult cats from 3 to 9 months old, the representation bias switched to predominantly oblique orientations. These age-dependent changes in the orientation representation bias imply that orientation maps continue to elaborate within postnatal 1 year with the consolidation of spatial frequency selectivity. We conclude that both intrinsic and mutual factors lead to the development of orientation maps and spatial frequency selectivity.

Origins of strabismus and loss of binocular vision

“…Orientation-selective circuits in V1 also start to form before visual experience begins. The same applies to circuits encoding spatial frequency (Tani et al, 2012). This is possible because spontaneous neural activity in the retina is highly structured, and thus allows the transmission of very precise messages to the central nervous system.…”

“…Progressively, most of them also become “binocular,” i.e., able to be activated through both eyes while they are initially monocular (e.g., Frégnac and Imbert, 1978; Milleret et al, 1988). In parallel, cortical maps corresponding to each of these attributes of the visual scene, including the retinotopic map encoding space, develop (e.g., Chapman et al, 1996; Crair et al, 1998; Smith and Trachtenberg, 2007; White and Fitzpatrick, 2007; Tani et al, 2012 for review). The different types of eye movements (saccades, pursuits) also mature with age (e.g., Ingster-Moati et al, 2009; Bucci and Seassau, 2012, 2014; cf.…”

Living Brain Optical Imaging: Technology, Methods and Applications

“…In the latter case, a recording chamber made of appropriate materials (plastic, metal, dental cement or a combination of these) are usually mounted on the skull with anchoring screws. The interior of the chamber is filled with mineral or silicone oil, agar or artificial cerebrospinal fluid (ACSF) [4, 20], which contains antibiotic and sometimes medicine to suppress growth of the connective tissue that makes the surface non-transparent and inappropriate for imaging [57, 58]. After the experiment, the chamber is covered with a special cap to protect the cortical surface.…”

“…After the experiment, the chamber is covered with a special cap to protect the cortical surface. During experiments, the cap and agar gel are removing and the chamber is filled again with fresh agar gel, ACSF, or silicone oil and a cover glass is placed on top [27, 58]. Such methods allow combining of imaging with electrophysiological recording.…”

“…Since the 90's, it has been employed to obtain information about the functional domain in the mammal's visual cortex. Several teams [6, 19, 57, 58] used IOS imaging and found that cortical regions that respond best to one orientation form highly ordered patches rather than elongated bands. It was an important step on the long road of studies of ocular dominance and orientation columns by IOS, along with their functions in the processing of visual information.…”