title: Schedule-induced polydipsia is associated with increased spine density in dorsolateral striatum neurons.
abstract: Schedule-induced polydipsia (SIP) is an adjunctive behavior in which rats exhibit excessive drinking as a consequence of intermittent feeding, and it has been proposed as a candidate model to study the development of compulsive and repetitive behavior. Although several brain structures are involved in compulsive behavior, it has been suggested that alterations in fronto-striatal circuits may underlie compulsive spectrum disorders. In the present work, we examined whether SIP would induce modifications in dorsolateral striatum (DLS) and anterior prefrontal cortex (aPFC) neurons. Specifically, the effects of 20 sessions of SIP were determined in the dendrites of DLS medium spiny neurons and in the basal dendritic arbors of layer V pyramidal cells in the aPFC. The structure, size and branching complexity in aPFC neurons were also studied. Results showed that SIP resulted in an increase in dendritic spine density in DLS neurons. Moreover, dendritic spine density was highly correlated with the level of drinking in animals subjected to SIP. By contrast, we observed no differences either in dendritic spine density or in the morphological structure of the dendrites of the aPFC in SIP rats compared to their control counterparts. We hypothesize that SIP-induced structural plasticity in DLS neurons could be related to inflexible response in compulsive behavior. The findings of this study could provide new insights into the involvement of particular cell populations of the dorsolateral striatum and anterior prefrontal cortex regions in compulsive spectrum disorders.
authors.affiliation: Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), 28040 Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Íbias
authors.affiliation: Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), 28040 Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Soria-Molinillo
authors.affiliation: Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Campus de Montegancedo s/n, Pozuelo de Alarcón 28223, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Kastanauskaite
authors.affiliation: Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), 28040 Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Orgaz
authors.affiliation: Instituto Cajal (CSIC), CIBERNED and Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Campus de Montegancedo s/n, Pozuelo de Alarcón 28223, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: DeFelipe
authors.affiliation: Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), 28040 Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Pellón
authors.affiliation: Departamento de Psicología Básica I, Facultad de Psicología, Universidad Nacional de Educación a Distancia (UNED), 28040 Madrid, Spain; Laboratorio Cajal de Circuitos Corticales (CTB), Universidad Politécnica de Madrid, Campus de Montegancedo s/n, Pozuelo de Alarcón 28223, Madrid, Spain. Electronic address: mmiguens@psi.uned.es.
authors.forename: M
authors.initials: M
authors.lastname: Miguéns
mesh_terms: D000818:Animals; D003192:Compulsive Behavior / Q000473:pathology / Q000503:physiopathology; D003342:Corpus Striatum / Q000473:pathology / Q000503:physiopathology*; D049229:Dendritic Spines / Q000473:pathology / Q000502:physiology*; D005508:Food Deprivation / Q000502:physiology*; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D010784:Photomicrography; D059606:Polydipsia / Q000473:pathology / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000473:pathology / Q000503:physiopathology; D011897:Random Allocation; D017208:Rats, Wistar
keywords: adjunctive behavior; dendritic spines; neuron morphology; plasticity; prefrontal cortex