Britannica Sources used in this answer

What role does cAMP play in sensitization in Aplysia californica?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

neuroplasticity The fundamental cell of the nervous system is the neuron. Neurons in a human brain are shown here.

In the marine snail Aplysia californica, sensitization is a form of neuroplasticity where a reflex response increases in strength following additional stimulation.1

The underlying mechanism for this behavioral change is presynaptic facilitation. This process is driven by an increase in the second messenger cAMP within the terminals of the sensory neurons. By acting as a signaling molecule, cAMP facilitates the transmission of information at the synapse, leading to an increase in synaptic efficacy. Over the long term, this sensitization can even result in structural changes, such as an increase in the number of active zones at the nerve terminals.1

These molecular mechanisms demonstrate how simple organisms provide critical insights into the fundamental processes of learning and memory that are conserved across the phylogenetic tree.1