title: Role of the supraoptic decussation in the development of asymmetry of brain function in the chicken.
abstract: The supraoptic decussation plays an important role in the development of asymmetry of brain function for visual discrimination learning in the chicken. Lesioning the decussation on day 2 has no effect on the asymmetry normally revealed by unilaterally treating either the left or right forebrain hemisphere with cycloheximide on day 4 of life. However, the lesion removes the asymmetry revealed by cycloheximide treatment on day 8 and reverses that revealed by treatment on day 10, albeit to a lesser extent. The asymmetry of learning performance between the left and right eyes present in untreated chickens tested monocularly in the second week of life is also removed by lesioning the supraoptic decussation. Thus, in the first week of life functional asymmetry is present but not dependent on left-to-right side coupling via the supraoptic decussation. The difference between lesioning during the first and second week of life may relate to the relative degree of maturation in the supraoptic decussation.
mesh_terms: D000367:Age Factors; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000254:growth & development*; D002645:Chickens / Q000254:growth & development*; D003513:Cycloheximide / Q000494:pharmacology; D004193:Discrimination Learning / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology*; D008297:Male; D014795:Visual Pathways / Q000187:drug effects / Q000254:growth & development; D014796:Visual Perception / Q000502:physiology*
chemical_list: D003513:Cycloheximide