title: Repetitive fluoxetine treatment affects long-term memories but not learning.
abstract: Fluoxetine is currently being administered for long-term maintenance and for prophylactic reasons following the remission of depressive symptoms and several other psychiatric and neurological conditions. We have previously found that in naïve adult male rats, repetitive administration of fluoxetine induced maturation of telencephalic dendritic spines. This finding was associated with the presence of a higher proportion of GluA2- and GluN2A-containing glutamate receptors. To gain further insight into the possible consequences of such synaptic re-organization on learning and memory processes, we evaluated hippocampal- and non-hippocampal-dependent memories following administration of 0.7 mg/kg fluoxetine for four weeks. Standard behavioral tasks were used: the Morris Water Maze (MWM) and Object Location Memory (OLM) tasks to assess spatial memory and the Novel Object Recognition (NOR) task to assess recognition memory. We found that treated rats showed normal learning and short-term memory (1 h post-learning). However, either recent (24 h) or remote (17 days) memories were impaired depending upon the task. Interestingly, spatial memory impairment spontaneously reverted after 6 weeks of fluoxetine withdrawal.
authors.affiliation: Laboratorio de Neurociencias, Universidad de los Andes, Chile.
authors.forename: Estibaliz
authors.initials: E
authors.lastname: Ampuero
authors.forename: Jimmy
authors.initials: J
authors.lastname: Stehberg
authors.forename: Daniela
authors.initials: D
authors.lastname: Gonzalez
authors.forename: Nicolas
authors.initials: N
authors.lastname: Besser
authors.forename: Monica
authors.initials: M
authors.lastname: Ferrero
authors.forename: Gabriela
authors.initials: G
authors.lastname: Diaz-Veliz
authors.forename: Ursula
authors.initials: U
authors.lastname: Wyneken
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Rubio
mesh_terms: D000818:Animals; D005473:Fluoxetine / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D057567:Memory, Long-Term / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D021641:Recognition, Psychology / Q000187:drug effects; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D013028:Space Perception / Q000187:drug effects
chemical_list: D005473:Fluoxetine; D017367:Selective Serotonin Reuptake Inhibitors