title: The role of ependymin in the development of long lasting synaptic changes.
abstract: 1.) Three types of training experiments (a complex motor task, avoidance conditioning and classical conditioning) in the goldfish and one in the mouse (T-maze learning) indicate that the brain extracellular glycoprotein (ependymin) has a role in the consolidation process of long-term memory formation. 2.) Direct ELISA measures of the concentration of ependymin in the brain extracellular fluid (ECF) indicate that its level decreases after goldfish learn to associate a light stimulus (cs) with the subsequent arrival of a shock (US): paired CS-US gave changes whereas an unpaired presentation of CS-US gave no changes in comparison to unstimulated controls. 3.) Ependymin is released into ECF and CSF as mixtures of three types of disulfide-linked dimers of two acidic polypeptide chains (M. W. 37 kDa and 31 kDa). It contains 10% carbohydrate as an N-linked glycan. 4.) Ependymin has the capacity to polymerize in response to events that deplete Ca2+ from the brain extracellular environment. A molecular hypothesis relating polymerization properties to the process of formation of long-lasting synaptic changes is proposed. 5.) Investigations of the pattern of regeneration of goldfish optic nerve and the mechanisms of long-term potentiation (LTP) of rat brain hippocampal slices suggest that ependymin has a role in the formation of long-lasting synaptic changes. The E.M. data show that polymerized products which stain with anti-ependymin sera accumulate at synapses and in new spines after LTP.
authors.affiliation: Ralph Lowell Laboratories, McLean Hospital, Harvard Medical School, Belmont, MA 02178.
authors.forename: V E
authors.initials: VE
authors.lastname: Shashoua
mesh_terms: D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D003530:Cyprinidae / Q000502:physiology*; D006054:Goldfish / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D008568:Memory / Q000502:physiology; D051379:Mice; D009419:Nerve Tissue Proteins / Q000502:physiology*; D013569:Synapses / Q000502:physiology*
chemical_list: D009419:Nerve Tissue Proteins; C031632:ependymins