Transcription mechanism in a single neuron to control conditioned taste aversion in the pond snail lymnaea stagnalis

Conditioned taste aversion (CTA) can be classically conditioned in the pond snail Lymnaea stagnalis and subsequently be consolidated into long-term memory (LTM). The neural mechanism that subserves CTA-LTM are summarized as follows: A polysynaptic inhibitory postsynaptic potential recorded in the neuron 1 medial (N1M) cell in the buccal ganglion of the conditioned snails as a result of activation of the cerebral giant cell (CGC) is larger and lasts longer than that in control snails. The N1M cell is the member of feeding central pattern generator, whereas the CGC is a multimodal interneuron thought to play a key role in the feeding behavior. The CGC is serotonergic and the secretion of setotonin from the CGC is controlled by cAMP, PKA and CREB, showing that these signaling cascades are involved in CTA. In this chapter we review the transcription mechanism, partuculary the cascades of cAMP-PKA-CREB and CCAAT/enhancer binding protein, in CTA-LTM.