Brain protein metabolism and the acquisition of new behaviors. II. Immunological studies of the α, β and γ proteins of goldfish brain

Abstract

In a previous study, the labeling pattern of three proteins (α, β and γ) in goldfish brain was found to change after the animals successfully acquired a new pattern of behavior. In the present study, these proteins were isolated from the brain cytoplasmic fraction, purified by successive gel electrophoresis and used as antigens to immunize rabbits. Antisera containing antibodies to two of the proteins (β and γ) were obtained. These gave single precipitin bands when plated against the antigens and a mixture of the total cytoplasmic proteins. The distribution of β and γ in brain subcellular fractions and in a variety of goldfish tissues was determined by immunodiffusion methods. γ was specific to brain. The β protein cross-reacted but was not identical to a widely distributed substance in plasma, liver and kidney. Both β and γ appear to be species specific in that no cross-reactivity was obtained with mouse, chick or rat brain proteins. Immunological methods, in combination with double labeling experiments were used to establish that the β and γ antigens were proteins which were normally present in goldfish brain. Both the β and γ antisera were equally capable of specifically precipitating the proteins which were differentially labeled after training as well as purified proteins of the same molecular weight present in the brains of control animals. These results suggest that the acquisition of a new pattern of behavior can increase the demand for the synthesis of specific proteins (β and γ) normally present in goldfish brain.