Year: 2015
Type: preprint
Abstract: Consolidation of implicit memory in the invertebrate Aplysia and explicit memory in the mammalian hippocampus are associated with remodeling and growth of preexisting synapses and the formation of new synapses.Here, we compare and contrast structural components of the synaptic plasticity that underlies these two distinct forms of memory.In both cases, the structural changes involve time-dependent processes.Thus, some modifications are transient and may contribute to early formative stages of long-term memory, whereas others are more stable, longer lasting, and likely to confer persistence to memory storage.In addition, we explore the possibility that trans-synaptic signaling mechanisms governing de novo synapse formation during development can be reused in the adult for the purposes of structural synaptic plasticity and memory storage.Finally, we discuss how these mechanisms set in motion structural rearrangements that prepare a synapse to strengthen the same memory and, perhaps, to allow it to take part in other memories as a basis for understanding how their anatomical representation results in the enhanced expression and storage of memories in the brain.S antiago Ramo ´n y Cajal (1894) used the in- sights provided by his remarkable light microscopic observations of neurons selectively stained with the Golgi method to propose the first cellular theory of memory storage as an anatomical change in the functional connections between nerve cells, later called synapses (Sherrington 1897).For most of the last century, chemical synapses were thought to convey in-formation in only one direction-from the presynaptic to the postsynaptic neuron.It now is clear that synaptic transmission is a bidirectional and self-modifiable form of cell -cell communication (Peters et al. 1976;Jessell and Kandel 1993).This appreciation of reciprocal signaling between pre-and postsynaptic elements is consistent with other forms of intercellular communication and provides a concep-
Language: English
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2203645773