Rat-strain dependent changes of dendritic and spine morphology in the hippocampus after cocaine self-administration.
We previously showed that cocaine self-administration increases spine density in CA1 hippocampal neurons in Lewis (LEW) but not in Fischer 344 (F344) rats. Dendritic spine morphology is intimately related to its function. Thus, we conducted a 3D morphological analysis of CA1 dendrites and dendritic spines in these two strains of rats. Strain-specific differences were observed prior to cocaine self-administration: LEW rats had significantly larger dendritic diameters but lower spine density than the F344 strain. After cocaine self-administration, proximal dendritic volume, dendritic surface area and spine density were increased in LEW rats, where a higher percentage of larger spines were also observed. In addition, we found a strong positive correlation between dendritic volume and spine morphology, and a moderate correlation between dendritic volume and spine density in cocaine self-administered LEW rats, an effect that was not evident in any other condition. By contrast, after cocaine self-administration, F334 rats showed decreased spine head volumes. Our findings suggest that genetic differences could play a key role in the structural plasticity induced by cocaine in CA1 pyramidal neurons. These cocaine-induced alterations could be related to differences in the memory processing of drug reward cues that could potentially explain differential individual vulnerability to cocaine addiction.
Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia, (UNED), Spain.|Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Spain.
Abraham
A
Selvas
Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia, (UNED), Spain.
Santiago M
SM
Coria
Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Spain.
Asta
A
Kastanauskaite
Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Spain.
Isabel
I
Fernaud-Espinosa
Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Spain.|Instituto Cajal (CSIC), Spain.|CIBERNED, Spain.
Javier
J
DeFelipe
Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia, (UNED), Spain.
Emilio
E
Ambrosio
Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Spain.|Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), Spain.
Miguel
M
Miguéns
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003042:Cocaine / Q000008:administration & dosage / Q000494:pharmacology*; D049229:Dendritic Spines / Q000187:drug effects*; D018765:Dopamine Uptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D023421:Models, Animal; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D012646:Self Administration; D013045:Species Specificity
D018765:Dopamine Uptake Inhibitors; D003042:Cocaine
3D neuron analysis; CA1; Fischer 344; Lewis; genetic background; intracellular injections