title: Effects of morphine on brain plasticity.
abstract: BACKGROUND
  Morphine shares with other opiates and drugs of abuse the ability to modify the plasticity of brain areas that regulate the morphology of dendrites and spines, which are the primary sites of excitatory synapses in regions of the brain involved in incentive motivation, rewards, and learning.
  
  
  OBJECTIVE
  In this review we discuss the impact of morphine use during the prenatal period of brain development and its long-term consequences in murines, and then link those consequences to similar effects occurring in human neonates and adults.
  
  
  METHODS
  Repeated exposure to morphine as treatment for pain in terminally ill patients produces long-term changes in the density of postsynaptic sites (dendrites and spines) in sensitive areas of the brain, such as the prefrontal cortex, the limbic system (hippocampus, amygdala), and caudate nuclei and nucleus accumbens. This article reviews the cellular mechanisms and receptors involved, primarily dopaminergic and glutamatergic receptors, as well as synaptic plasticity brought about by changes in dendritic spines in these areas.
  
  
  CONCLUSIONS
  The actions of morphine on both developing and adult brains produce alterations in the plasticity of excitatory postsynaptic sites of the brain areas involved in limbic system functions (reward and learning). Doctors need further studies on plasticity in dendrites and spines and on signaling molecules, such as calcium, in order to improve treatments for addiction.
authors.affiliation: División de Ciencias de la Salud e Ingenierías, Universidad de Guanajuato, Campus Celaya-Salvatierra, Celaya, Guanajuato, México.
authors.forename: V
authors.initials: V
authors.lastname: Beltrán-Campos
authors.affiliation: División de Ciencias de la Salud e Ingenierías, Universidad de Guanajuato, Campus Celaya-Salvatierra, Celaya, Guanajuato, México.
authors.forename: M
authors.initials: M
authors.lastname: Silva-Vera
authors.affiliation: División de Ciencias de la Salud e Ingenierías, Universidad de Guanajuato, Campus Celaya-Salvatierra, Celaya, Guanajuato, México.
authors.forename: M L
authors.initials: ML
authors.lastname: García-Campos
authors.affiliation: Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Campus UNAM-Juriquilla, Juriquilla, Querétaro, México. Electronic address: yoldi@servidor.unam.mx.
authors.forename: S
authors.initials: S
authors.lastname: Díaz-Cintra
mesh_terms: D000679:Amygdala / Q000187:drug effects; D000818:Animals; D001921:Brain / Q000187:drug effects*; D049229:Dendritic Spines / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects; D006801:Humans; D009020:Morphine / Q000494:pharmacology*; D009473:Neuronal Plasticity / Q000187:drug effects*; D011957:Receptors, Opioid
chemical_list: D011957:Receptors, Opioid; D009020:Morphine
keywords: Brain plasticity; Dendritic spines; Espinas dendríticas; Morfina; Morphine; Opiate receptors; Plasticidad cerebral; Receptores opiáceos