Processes of functional plasticity, i.e. long-lasting changes of the
strength of synaptic connectivity in response to relative short-lasting
afferent stimulation, are the most likely mechanisms underlying memory
storage in the adult brain. The best studied models of functional
plasticity are long-term potentiation (LTP) and long-term depression
(LTD). Rolipram, a specific type IV- specific cAMP phosphodiesterase
(PDE) inhibitor, was used in my initial studies to investigate its
effect on late plastic events during functional CA1 plasticity in rat
hippocampal slices in vitro. In the later part of my studies, I was
interested to investigate the question of what exactly is the putative
nature of the synaptic tag. Are there specific "tags" for LTP and LTD?