Effects of an Imprinting Procedure on Regional Incorporation of Tritiated Lysine into Protein of Chick Brain

Abstract

IN many different animals and in a variety of circumstances, the rates of protein and RNA synthesis in the central nervous system seem to be affected by environmental stimulation^1–3 although this relationship is not well defined. One promising situation which may help to clarify the relations is found shortly after hatching in many precocial birds. At this stage environmental stimuli can exert a long term effect on social behaviour. The process by which a bird's preference for a particular object becomes restricted to that object is known as “imprinting”^4,5. The situation is admittedly complicated in that any effects of experience on the nervous system are superimposed on maturational changes that proceed in the absence of such experience. Nevertheless, potential advantages of the imprinting situation are that the previous experience of the animal is very limited, the initial stages of the learning process are rapid and, in the absence of appropriate stimulation, the development of a preference can be delayed. Here we describe the effects of visual experience in the imprinting situation on the incorporation of tritiated lysine into protein of different regions of the chick's brain.