The relevance of the endocrine condition in microglia morphology and dendrite complexity of doublecortin-associated neurons in young adult and middle-aged female rats exposed to acute stress.

Menopause, natural or surgical, might facilitate the onset of psychiatric pathologies. Some reports suggest that their severity could increase if the decline of ovarian hormones occurs abruptly and before natural endocrine senescence. Therefore, we compared the effects of ovariectomy on microglia's morphological alterations, the complexity of newborn neurons, and the animal's ability to cope with stress. Young adult (3 months) and middle-aged (15 months) female Wistar rats were subjected to an ovariectomy (OVX) or were sham-operated. After 3 weeks, animals were assigned to one of the following independent groups: (1) young adult OVX + no stress; (2) young adult sham + no stress; (3) young adult OVX + stress; (4) young adult sham + stress; (5) middle-aged OVX + no stress; (6) middle-aged sham + no stress; (7) middle-aged OVX + stress; (8) middle-aged sham + stress. Acute stress was induced by forced swimming test (FST) exposure. Immobility behavior was scored during FST and 30 min after; animals were euthanized, their brains collected and prepared for immunohistochemical detection of Iba-1 to analyze morphological alterations in microglia, and doublecortin (DCX) detection to evaluate the dendrite complexity of newborn neurons. OVX increased immobility behavior, induced microglia morphological alterations, and reduced dendrite complexity of newborn neurons in young adult rats. FST further increased this effect. In middle-aged rats, the main effects were related to the aging process without OVX or stress exposure. In conclusion, surgical menopause favors in young adult rats, but not in middle-aged, the vulnerability to develop immobility behavior, retracted morphology of microglial cells, and decreased dendrite complexity of newborn neurons.

Clinical and Functional Connectivity Outcomes of 5-Hz Repetitive Transcranial Magnetic Stimulation as an Add-on Treatment in Cocaine Use Disorder: A Double-Blind Randomized Controlled Trial.

BACKGROUND: Cocaine use disorder (CUD) is a global condition lacking effective treatment. Repetitive transcranial magnetic stimulation (rTMS) may reduce craving and frequency of cocaine use, but little is known about its efficacy and neural effects. We sought to elucidate short- and long-term clinical benefits of 5-Hz rTMS as an add-on to standard treatment in patients with CUD and discern underlying functional connectivity effects using magnetic resonance imaging. METHODS: A total of 44 patients with CUD were randomly assigned to complete the 2-week double-blind randomized controlled trial (acute phase) (sham [n = 20, 2 female] and active [n = 24, 4 female]), in which they received two daily sessions of rTMS on the left dorsolateral prefrontal cortex (PFC). Subsequently, 20 patients with CUD continued to an open-label maintenance phase for 6 months (two weekly sessions for up to 6 mo). RESULTS: rTMS plus standard treatment for 2 weeks significantly reduced craving (baseline: 3.9 ± 3.6; 2 weeks: 1.5 ± 2.4, p = .013, d = 0.77) and impulsivity (baseline: 64.8 ± 16.8; 2 weeks: 53.1 ± 17.4, p = .011, d = 0.79) in the active group. We also found increased functional connectivity between the left dorsolateral PFC and ventromedial PFC and between the ventromedial PFC and right angular gyrus. Clinical and functional connectivity effects were maintained for 3 months, but they dissipated by 6 months. We did not observe reduction in positive results for cocaine in urine; however, self-reported frequency and grams consumed for 6 months were reduced. CONCLUSIONS: With this randomized controlled trial, we show that 5-Hz rTMS has potential promise as an adjunctive treatment for CUD and merits further research.

An overview of repetitive transcranial magnetic stimulation (rTMS) in Alzheimer's disease / La estimulación magnética transcraneal repetitiva (EMTr) como una alternativa de tratamiento en la enfermedad de Alzheimer

Abstract Background Alzheimer's disease (AD) is the most frequent neurocognitive disorder. It affects 50% to 75% of the cases of dementia, and is characterized by a progressive cognitive decline that hinders behavior and functionality. Its etiology is still uncertain, and the efficiency of treatments is limited. Repetitive transcranial magnetic stimulation (rTMS) has been used as an alternative therapeutic strategy, but the clinical impact on Alzheimer's disease has hardly been studied. Objective To describe the effects of rTMS on cognition, the behavioral and psychological symptoms of dementia (BPSD), and functionality, considering the various modes of application. Method The PubMed, ScienceDirect, and PsycInfo databases were consulted using key words relating to the topic of study. Articles published between 2006 and 2016 were selected. Results The studies that have assessed the clinical effect of rTMS have used various parameters to stimulate and compare the different cortical areas, principally the dorsolateral prefrontal cortex. A variety of benefits have been proposed for patients with Alzheimer's disease in cognitive domains such as language and episodic memory, as well as behavior and functionality in everyday activities. Discussion and conclusion rTMS has been suggested as a possible treatment for AD, and the results indicate the need for further studies with different methodological designs and more participants, in addition to cognitive rehabilitation techniques. The objective is to identify the most efficient parameters for stimulation and to explore new cortical targets.

Resumen Antecedentes La enfermedad de Alzheimer (EA) es el trastorno neurocognitivo más frecuente. Afecta de 50 a 75% de los casos de demencia y se caracteriza por un declive cognitivo progresivo que perjudica la conducta y funcionalidad. Su etiología es aún incierta y la eficacia de los tratamientos limitada. La estimulación magnética transcraneal repetitiva (EMTr) se ha utilizado como una estrategia terapéutica alternativa, pero se ha estudiado poco el impacto clínico que tiene en la EA. Objetivo Describir los efectos de la EMTr sobre la cognición y los síntomas psicológicos y conductuales de la demencia (SPCD), así como en la funcionalidad, considerando las diferentes modalidades de aplicación. Método Se consultaron las bases de datos PubMed, ScienceDirect y PsycInfo utilizando palabras clave relacionadas con el tema de estudio. Se seleccionaron los artículos publicados de 2006 a 2016. Resultados Los estudios que han evaluado el efecto clínico de la EMTr han utilizado diferentes parámetros de estimulación y comparaciones de diferentes áreas corticales, principalmente de la corteza prefrontal dorsolateral. Se postulan diferentes beneficios en pacientes con EA en dominios cognitivos como el lenguaje y la memoria episódica, así como en la conducta y en la funcionalidad de las actividades de la vida diaria. Discusión y conclusión La EMTr se ha sugerido como posible tratamiento para la EA. Los resultados favorecen la necesidad de realizar nuevos estudios con diferentes diseños metodológicos y mayor número de participantes, en combinación con técnicas de rehabilitación cognitiva. La perspectiva es identificar los parámetros de estimulación más eficaces y explorar nuevas dianas corticales.