Chapter 25 molecular mechanisms of learning and memory. Introduction studies on invertebrate animals have shown that hebb was right: memories can reside in synaptic alterations theoretical work studying the brains mechanism in regard to memories has shown that. Activity-dependent synaptic plasticity in the adult brain have a lot in common with those. Basic molecular mechanisms that alter that alter synaptic effectiveness are similar to operating in development for wiring of the brain memory formation mechanisms in invertebrates. Procedural learning procedural memories have characteristics that make them more ideal to study verses declarative memories. Formed along simple reflex pathways that link sensations to movement. Nonassociative learning typically broken down into two categories time in response to a single type of stimulus. Describes the change in behavioral response that occurs over. Learning to ignore a stimulus that lacks meaning due to its repeated. Sensitization previously evoked little or no reaction. Learning to intensify response to all stimuli, even those that.