Behavioral effects of early rearing conditions and neonatal lesions of the visual cortex in kittens.

Abstract

Kittens with neonatal lesions of the marginal and posterolateral gyri, along with unoperated controls, were reared either in an enriched environment or in laboratory cages. Kittens with lesions were inferior to controls at learning mazes and at discriminating forms and gratings, whether they were raised in enriched or impoverished conditions. Enrichment did not facilitate form or grating discrimination by either normal or operated cats, although such experience facilitated maze learning by both groups. It is concluded that early enrichment of sensorimotor experience was probably not the cause of the complete sparing of pattern vision after neonatal damage of the visual cortex reported in earlier studies. Discussion centers on task variables and completeness of the lesions as reasons for sparing of vision.Earlier work suggested that neonatal destruction of the visual cortex is far less incapacitating than later damage to the same regions (Doty, 1961;Murphy, Mize, & Schechter, 1975;Wetzel, Thompson, Horel, & Meyer, 1965). Wetzel and his colleagues reported essentially normal pattern vision by kittens with neonatal damage of the marginal and posterolateral gyri. In an attempt to analyze the mechanisms by which such visual sparing occurs, our laboratory initiated an extended sequence of ablationbehavioral experiments using kittens as subjects. However, the results from our first two projects failed to confirm the previous findings (Cornwell,

Environmental Approaches to Recovery of Function from Brain Damage: A Review of Animal Studies (1981 to 1991)

“…Several task specificities have already been mentioned incidentally (see 13,78) and there are now more than ten reports of mixed results of enrichment, either ''beneficial'' or not, depending on the behavioral task used. Kolb (this volume) stresses the need for a broad functional evaluation and for using a large behavioral and neurologic test battery in order to determine more accurately the effects of anyone factor on the general outcome of brain damage.…”

“…13,24,42,55,56) showed that postoperative enriched housing (pen-rearing) facilitated Hebb-Williams maze learning in both normal kittens and kittens with neonatal lesions of the marginal and posterolateral gyri, although such experience did not facilitate form or grating discrimination either in normal or operated cats. In both cats and monkeys, Lacou~5 found that functional recovery following unilateral vestibular neurectomy developed only in unrestrained animals, i.e., when they had the possibility of using information elicited by active sensorimotor exploration; in contrast, recovery was blocked and delayed when the animals had no opportunity to interact behaviorally with their environment.…”

Role of the caudate nucleus in recovery from neonatal mediofrontal cortex lesions in the rat

“…Early investigations of this age-at-lesion effect suggested that extrastriate cortex, areas 18 and 19, or perhaps cortex of the supra-sylvian gyri, left intact following area 17 removal, were crucial for sparing of pattern vision (Cornwell, Overman, & Ross, 1978;Doty, 1971Doty, , 1973. Subsequent studies revealed the importance of variables such as specific rearing environment, age at time of testing, and task-related variables, which existed between the many studies of geniculocortical system function (reviewed by Cornwell & Overman, 1981). Nevertheless, the most consistent interpretation seems to be that neonatal "lesions which include most of areas 17 and 18 and much of area 19 produce serious trouble in discriminating patterns and forms, even if the suprasylvian visual areas are intact" (Cornwell & Overman, 1981 ;p.…”

“…Subsequent studies revealed the importance of variables such as specific rearing environment, age at time of testing, and task-related variables, which existed between the many studies of geniculocortical system function (reviewed by Cornwell & Overman, 1981). Nevertheless, the most consistent interpretation seems to be that neonatal "lesions which include most of areas 17 and 18 and much of area 19 produce serious trouble in discriminating patterns and forms, even if the suprasylvian visual areas are intact" (Cornwell & Overman, 1981 ;p. 858).…”

Nurturing brain plasticity: impact of environmental enrichment

“…[24][25][26][27] Although EE research has been mostly focused on rodents, similar effects have been reported in several species of mammals (gerbils, ground squirrels, rabbits, cats and primates). [28][29][30][31][32] …”