Differential Regulation of the Period Genes in Striatal Regions following Cocaine Exposure

Several studies have suggested that disruptions in circadian rhythms contribute to the pathophysiology of multiple psychiatric diseases, including drug addiction. In fact, a number of the genes involved in the regulation of circadian rhythms are also involved in modulating the reward value for drugs of abuse, like cocaine. Thus, we wanted to determine the effects of chronic cocaine on the expression of several circadian genes in the Nucleus Accumbens (NAc) and Caudate Putamen (CP), regions of the brain known to be involved in the behavioral responses to drugs of abuse. Moreover, we wanted to explore the mechanism by which these genes are regulated following cocaine exposure. Here we find that after repeated cocaine exposure, expression of the Period (Per) genes and Neuronal PAS Domain Protein 2 (Npas2) are elevated, in a somewhat regionally selective fashion. Moreover, NPAS2 (but not CLOCK (Circadian Locomotor Output Cycles Kaput)) protein binding at Per gene promoters was enhanced following cocaine treatment. Mice lacking a functional Npas2 gene failed to exhibit any induction of Per gene expression after cocaine, suggesting that NPAS2 is necessary for this cocaine-induced regulation. Examination of Per gene and Npas2 expression over twenty-four hours identified changes in diurnal rhythmicity of these genes following chronic cocaine, which were regionally specific. Taken together, these studies point to selective disruptions in Per gene rhythmicity in striatial regions following chronic cocaine treatment, which are mediated primarily by NPAS2. © 2013 Falcon et al

<i>Clock</i>, <i>Npas2</i> and <i>Bmal1</i> expression after cocaine treatment.

<p>Real-time PCR analysis of <i>Clock, Npas2,</i> and <i>Bmal1</i> expression in the CP and NAc following saline, acute (15 mg/kg, 1 day), or chronic cocaine treatment (15 mg/kg, 7 days) in wild type mice. *p<0.05 by t-test, n = 6.</p

Effect of the <i>Npas2</i> mutation on <i>Per</i> gene induction following cocaine.

<p>Real-time PCR analysis of <i>mPer1, mPer2, and mPer3</i> expression in the CP and NAc following chronic treatment (15 mg/kg, 7 days) with saline or cocaine in wild type and <i>Npas2</i> mutant mice. Shown are the fold changes in cocaine treated animals relative to saline treated animals. *p<0.05, **p<0.01, ***p< 0.001 by t-test. n = 5.</p

<i>Per</i> gene and protein expression after cocaine treatment.

<p>Real-time PCR analysis of <i>mPer1, mPer2</i> and <i>mPer3</i> expression in the CP (A) and NAc (B) following saline, acute (15 mg/kg, 1 day), or chronic cocaine treatment (15 mg/kg, 7 days) in wild type mice. *p<0.05, **p<0.01 by t-test. n = 6. (C, D) Cocaine (15 mg/kg) or saline was given chronically (7 days) i.p. Protein levels were measured 24 hrs later using western blot analysis in the CP and NAc. GAPDH was measured as a loading control. n = 5–8. Representative blots are shown (C) and the percent change in cocaine vs saline is shown (D). *p<0.05, **p<0.01 by t-test.</p

Chronic cocaine alters <i>Npas2</i> rhythmic expression only in the NAc, whereas <i>Clock</i> is unchanged.

<p>(A) <i>Clock</i> gene expression (mean ± SEM, n =  6–9) in the NAc and CP is unaltered by chronic cocaine (B) <i>Npas2</i> rhythmicity in the NAc is abolished following chronic cocaine and a significant upregulation was observed at ZT 4 (*p<0.05). Dark background indicates lights-off.</p

Dibujo De Ingeniería 1-IN170-201801

Descripción: Curso introductorio en la carrera de Ingeniería Industrial dirigido a los estudiantes del segundo ciclo que les permitirá elaborar e interpretar planos de ingeniería industrial utilizando instrumentos de dibujo el software AutoCAD y aplicando las normativas internacionales. Al finalizar el curso el estudiante puede dibujar construcciones geométricas proyecciones ortogonales de piezas industriales isometrías de piezas industriales e interpretar planos de ingeniería industrial teniendo en cuenta las normativas y estándares internacionales de dibujo.Propósito: El curso busca desarrollar la competencia general de pensamiento crítico y la competencia específica de aprendizaje continuo y autónomo en el Nivel 1:Los alumnos deben ser hábiles en usar instrumentos de búsqueda de información que les permita mantenerse actualizados en su profesión: recursos de Internet revistas de ingeniería patentes normas técnicas etc.El estudiante utiliza toda la información disponible en las fuentes mencionadas para la elaboración y lectura de planos de ingeniería industrial.El prerrequisito del curso es Fundamentos de Ingeniería Industrial

Dibujo De Ingeniería 1-IN170-201801

Descripción: Curso introductorio en la carrera de Ingeniería Industrial dirigido a los estudiantes del segundo ciclo que les permitirá elaborar e interpretar planos de ingeniería industrial utilizando instrumentos de dibujo el software AutoCAD y aplicando las normativas internacionales. Al finalizar el curso el estudiante puede dibujar construcciones geométricas proyecciones ortogonales de piezas industriales isometrías de piezas industriales e interpretar planos de ingeniería industrial teniendo en cuenta las normativas y estándares internacionales de dibujo.Propósito: El curso busca desarrollar la competencia general de pensamiento crítico y la competencia específica de aprendizaje continuo y autónomo en el Nivel 1:Los alumnos deben ser hábiles en usar instrumentos de búsqueda de información que les permita mantenerse actualizados en su profesión: recursos de Internet revistas de ingeniería patentes normas técnicas etc.El estudiante utiliza toda la información disponible en las fuentes mencionadas para la elaboración y lectura de planos de ingeniería industrial.El prerrequisito del curso es Fundamentos de Ingeniería Industrial

NPAS2 Regulation of Anxiety-Like Behavior and GABAA Receptors

Abnormal circadian rhythms and circadian genes are strongly associated with several psychiatric disorders. Neuronal PAS Domain Protein 2 (NPAS2) is a core component of the molecular clock that acts as a transcription factor and is highly expressed in reward- and stress-related brain regions such as the striatum. However, the mechanism by which NPAS2 is involved in mood-related behaviors is still unclear. We measured anxiety-like behaviors in mice with a global null mutation in Npas2 (Npas2 null mutant mice) and found that Npas2 null mutant mice exhibit less anxiety-like behavior than their wild-type (WT) littermates (in elevated plus maze, light/dark box and open field assay). We assessed the effects of acute or chronic stress on striatal Npas2 expression, and found that both stressors increased levels of Npas2. Moreover, knockdown of Npas2 in the ventral striatum resulted in a similar reduction of anxiety-like behaviors as seen in the Npas2 null mutant mouse. Additionally, we identified Gabra genes as transcriptional targets of NPAS2, found that Npas2 null mutant mice exhibit reduced sensitivity to the GABAa positive allosteric modulator, diazepam and that knockdown of Npas2 reduced Gabra1 expression and response to diazepam in the ventral striatum. These results: (1) implicate Npas2 in the response to stress and the development of anxiety; and (2) provide functional evidence for the regulation of GABAergic neurotransmission by NPAS2 in the ventral striatum