ABSTRACT
In conditioned taste aversion (CTA) and taste-potentiated odor aversion (TPOA) individuals learn to associate taste or odor with poisoning. This leads to subsequent aversion to that taste or odor. In nature, the poisoning is due to toxins in the foodstuff; in the laboratory, ip injection of LiCl is usually used to elicit transient malaise. Protein tyrosine phosphorylation is modulated in the course of action of the signal transduction pathways that regulate cellular differentiation and growth. It became apparent that tyrosine phosphorylation also plays a key function in neuronal activity and plasticity. Protein tyrosine phosphorylation, as a posttranslational modification, can persist for only seconds to possibly minutes or hours. Therefore, even when considered as a mechanism of cellular memory, protein tyrosine phosphorylation per se cannot instantiate long-term changes. The observation that protein synthesis is necessary for memory consolidation is construed as indicating that modulation of gene expression is required for the formation of long-term memory.
