Acquisition of visuomotor behavior after neonatal tectal lesions in the hamster: The role of visual experience.

Abstract

After neonatal damage to the midbrain tectum, hamsters exhibit as adults substantially reorganized retinal projections to the thalamus and midbrain. These experiments investigated the pattern of acquisition of a range of visuomotor capacities in hamsters with neonatal tectal damage, and the role of visual experience in this acquisition, by examining the time course of visuomotor development and the effects of dark-rearing on visuomotor behavior. These hamsters acquired visual orientation and pursuit at the same age as normal hamsters, but orientation and pursuit were impaired and exhibited no improvement over time. Photophobia and edge and depth sensitivity were relatively unaffected. Dark-rearing disrupted all visuomotor behavior in the midbrain-damaged animals but had no effect on normal animals. These results are consistent with a dominant role of neocortex in the residual visuomotor capacities of animals with neonatal ablations of the midbrain tectum

The role of the superior colliculus in visually guided locomotion and visual orienting in the hamster

“…Lesion extent in the animals subjected to heat lesion of the superficial layers of the superior colliculus at birth was remarkably uniform and similar to lesions reported previously by Finlay (1979), Finlay, Marder, andCordon (1980), andSchneider (1970). The entire superficial gray layer of the superior colliculus was removed, with the exception of minor sparing at the most lateral margin.…”

Experience-Independent Development of the Hamster Circadian Visual System

“…To assess acuity of the primary visual system, on week 15 hamsters from experiment 2 were challenged on week 15 with tasks that required them to identify and respond to a visual target (using procedures adapted from Finlay et al [47]). For 2 days prior to behavioral testing, hamsters were habituated to an aliquot of unsalted sunflower seeds (David, Omaha, NE), which they readily consumed.…”

“…Behavioral tests of object recognition and motion detection [47] were performed in the following order: (1) CHEEK: a sunflower seed was held adjacent to the right cheek with a pair of stainless steel forceps. (2) NEAR: the seed was held in forceps approximately 2 cm in front of the nose.…”

Behavioral testing and preliminary analysis of the hamster visual system

“…Assessing visually guided behavior has been well worked out for the Syrian or Golden Hamster [1][2][3][4][5][6][7][8][9][10][11][12][13][14] . Because of their high motivation to hoard seeds, which they put into cheek pouches, they require no food deprivation.…”

“…We followed this protocol information in our recently published experiments showing return of visual function with regeneration of the optic tract in Syrian hamsters 1 . The details are based on the experiments described in that report; the behavioral assessments in this study followed a series of earlier studies published between 1967 and 1992 using the Syrian or Golden Hamster, Mesocricetus auratus [1][2][3][4][5][6][7][8][9][10][11][12][13][14] .…”