Structural Brain Changes Associated with Overweight and Obesity.

Obesity is a global health problem with a broad set of comorbidities, such as malnutrition, metabolic syndrome, diabetes, systemic hypertension, heart failure, and kidney failure. This review describes recent findings of neuroimaging and two studies of cell density regarding the roles of overnutrition-induced hypothalamic inflammation in neurodegeneration. These studies provided consistent evidence of smaller cortical thickness or reduction in the gray matter volume in people with overweight and obesity; however, the investigated brain regions varied across the studies. In general, bilateral frontal and temporal areas, basal nuclei, and cerebellum are more commonly involved. Mechanisms of volume reduction are unknown, and neuroinflammation caused by obesity is likely to induce neuronal loss. Adipocytes, macrophages of the adipose tissue, and gut dysbiosis in overweight and obese individuals result in the secretion of the cytokines and chemokines that cross the blood-brain barrier and may stimulate microglia, which in turn also release proinflammatory cytokines. This leads to chronic low-grade neuroinflammation and may be an important factor for apoptotic signaling and neuronal death. Additionally, significant microangiopathy observed in rat models may be another important mechanism of induction of apoptosis. Neuroinflammation in neurodegenerative diseases (such as Alzheimer's and Parkinson's diseases) may be similar to that in metabolic diseases induced by malnutrition. Poor cognitive performance, mainly in executive functions, in individuals with obesity is also discussed. This review highlights the neuroinflammatory and neurodegenerative mechanisms linked to obesity and emphasizes the importance of developing effective prevention and treatment intervention strategies for overweight and obese individuals.

Impairment of novelty-related theta oscillations and P3a in never medicated first-episode psychosis patients.

We explored the neurophysiological activity underlying auditory novelty detection in antipsychotic-naive patients with a first episode of psychosis (FEP). Fifteen patients with a non-affective FEP and 13 healthy controls underwent an active involuntary attention task along with an EEG acquisition. Time-frequency representations of power, phase locking, and fronto-parietal connectivity were calculated. The P3a event-related potential was extracted as well. Compared to controls, the FEP group showed reduced theta phase-locking and fronto-parietal connectivity evoked by deviant stimuli. Also, the P3a amplitude was significantly reduced. Moreover, reduced theta connectivity was associated with more severe negative symptoms within the FEP group. Reduced activity (phase-locking and connectivity) of novelty-related theta oscillations, along with P3a reduction, may represent a failure to synchronize large-scale neural populations closely related to fronto-parietal attentional networks, and might be explored as a potential biomarker of disease severity in patients with emerging psychosis, given its association with negative symptoms.

Cognitive Reserve and Executive Functions in Adults with Type 2 Diabetes.

BACKGROUND: Adults with type two diabetes mellitus (DM2) show cognitive deficits within the executive function domain. The detrimental effects of DM2 over executive function (EF) performance may be mediated by factors such as cognitive reserve (CR). CR mediates cognitive performance by delaying the appearance of clinical symptoms from subjacent brain pathology or attenuating the severity of such symptoms. Our main goal was to study the effects of CR on executive functions of adults with DM2. METHODS: Data from a total of 1,034 adults were included (362 women, 672 men). Subjects were categorized into four groups: subjects with DM2 and high CR (n = 235), control subjects with high CR (n = 265), subjects with DM2 and low CR (n = 298), and control subjects with low CR (n = 236). CR was quantified through 3 proxies: education, occupational complexity, and leisure activities. Executive functions were evaluated through visual scanning, verbal fluency, and backwards counting tasks. First, a series of four one-way ANOVAs was performed where group was included as a between-subject factor and executive function as a dependent variable. Second, a hierarchical multiple regression analysis was conducted to assess the weight of each CR proxy on EF performance. RESULTS: CR level significantly affected all executive function scores independently of the diabetes status. Hierarchical regression analyses indicated that years of education accounted for most of the variance in the model for executive function performance. In this study, we found that there is a significant effect of CR on executive function performance of DM2 subjects and education is the most important CR proxy.

Association between prolactin serum levels and cognitive function in chronic schizophrenia patients / Asociación de los niveles de prolactina con el funcionamiento cognitivo en pacientes con esquizofrenia crónic

Abstract Introduction Several studies have explored the relationship between serum prolactin levels, symptomatology, and cognitive dysfunction in individuals at high risk for psychosis and patients with a first psychotic episode. However, the relationship between such variables is poorly understood in the case of chronic patients. Objective To assess the relationship between prolactin levels, neuropsychological impairment, and symptom severity in patients with chronic schizophrenia. Method A total of 31 patients with diagnosis of schizophrenia were evaluated between May and December 2018. The age range was 18 to 60 years, with patients receiving antipsychotic treatment during a month at least. Data was obtained from clinical records, interviews, clinimetry, and with the application of the PANSS and the MCCB battery. For the prolactin measurement, the analysis was performed on a sample of 500 microliters of serum, with a chemiluminescence technique. Results The sample was comprised mostly by men (77.4%), with a mean age of 37.65 years, 13.29 years of formal education, and disease duration of 11.58 years. No correlations were observed between prolactin levels and PANSS components and subscales. Only in male patients is there a negative correlation was found between prolactin levels with the overall combined score of the MCCB battery and cognitive domains of reasoning and verbal learning. Discussion and conclusions Men diagnosed with schizophrenia may be particularly vulnerable to the negative effects of hyperprolactinemia on cognition. These preliminary data have clinical implications for close monitoring of prolactin and cognitive decline in males with schizophrenia. Theoretically, these data are suggestive of a protective effect of hormones in women with this condition.

Resumen Introducción Diversos estudios han explorado la relación entre los niveles de prolactina sérica, la sintomatología y la disfunción cognitiva en individuos con alto riesgo de psicosis y pacientes con un primer episodio psicótico. Sin embargo, la relación entre tales variables es poco comprendida en el caso de los pacientes crónicos con esquizofrenia. Objetivo Evaluar la relación entre los niveles de prolactina, el deterioro neuropsicológico y la severidad de los síntomas en pacientes crónicos. Método Se evaluó un total de 31 pacientes. El rango de edad fue de 18 a 60 años, quienes recibieron tratamiento antipsicótico durante un mes como mínimo. Los datos se obtuvieron de entrevistas y de la aplicación de la PANSS y la MCCB. La medición de la prolactina se realizó con una muestra de 500 microlitros de suero, con una técnica de quimioluminiscencia. Resultados La muestra estuvo compuesta en su mayoría por hombres (77.4%), con una edad media de 37.65 años, 13.29 años de escolaridad y una duración de la enfermedad de 11.58 años. No se observaron correlaciones entre los niveles de prolactina y los componentes y subescalas del PANSS. Sólo en los pacientes varones se da una correlación negativa entre los niveles de prolactina con la puntuación global combinada de la batería de MCCB y los dominios cognitivos de razonamiento y aprendizaje verbal. Discusión y conclusiones Los hombres diagnosticados con esquizofrenia pueden ser particularmente vulnerables a los efectos negativos de la hiperprolactinemia sobre la cognición. Teóricamente, estos datos sugieren un efecto protector de las hormonas en las mujeres con esta enfermedad.

A Postmortem Study of Frontal and Temporal Gyri Thickness and Cell Number in Human Obesity.

OBJECTIVE: This study aimed to compare cortex thickness and neuronal cell density in postmortem brain tissue from people with overweight or obesity and normal weight. METHODS: The cortex thickness and neuron density of eight donors with overweight or obesity (mean = 31.6 kg/m2 ; SD = 4.35; n = 8; 6 male) and eight donors with normal weight (mean = 21.8 kg/m2 ; SD = 1.5; n = 8; 5 male) were compared. All participants were Mexican and lived in Mexico City. Randomly selected thickness measures of different cortex areas from the frontal and temporal lobes were analyzed based on high-resolution real-size photographs. A histological analysis of systematic-random fields was used to quantify the number of neurons in postmortem left and right of the first, second, and third gyri of frontal and temporal lobe brain samples. RESULTS: No statistical difference was found in cortical thickness between donors with overweight or obesity and individuals with normal weight. A smaller number of neurons was found among the donors with overweight or obesity than the donors with normal weight at different frontal and temporal areas. CONCLUSIONS: A lower density of neurons is associated with overweight or obesity. The morphological basis for structural brain changes in obesity requires further investigation.

Regulación Emocional En Pacientes Con Esquizofrenia: Un Estudio Piloto / Emotion Regulation In Schizophrenia Patients: A Pilot Study

RESUMEN Antecedentes: Se ha reportado que los pacientes con esquizofrenia presentan alteraciones en el procesamiento emocional, específicamente en la percepción de emociones. Sin embargo, poco se sabe sobre otros aspectos de este proceso, como la regulación emocional. Objetivo: Evaluar y comparar la regulación emocional y neurocognición en pacientes con esquizofrenia y sujetos control, así como identificar correlaciones entre regulación emocional, neurocognición y datos demográficos. Método: Se evaluaron nueve pacientes (GE) y nueve controles (GC). Se obtuvieron datos demográficos, para evaluar regulación emocional se utilizó la Prueba de Inteligencia Emocional Mayer-Salovey Caruso, sección Manejo de Emociones y se realizó una breve evaluación neurocognitiva. Resultados: El GE tuvo un desempeño significativamente inferior que el GC en la prueba de regulación emocional y en neurocognición (p<.05). No se encontraron correlaciones entre regulación emocional, neurocognición, datos demográficos y clínicos. Discusión y conclusión: Los pacientes con esquizofrenia presentan menor capacidad de regulación emocional y alteraciones en la neurocognición. Estos resultados son consistentes con lo descrito en la literatura.

ABSTRACT Background: It has been reported that schizophrenia patients display emotional processing impairments, specifically in the emotion perception domain. However, less is known about other domains of emotional processing, like emotion regulation. Objective: The aim of this study was to assess and compare emotion regulation abilities and neurocognition in schizophrenia patients and healthy controls, as well as to identify correlations between emotion regulation, neurocognition and demographic data. Methods: 9 patients (GE) and 9 controls (GC) were recruited. Demographic data was obtained. To assess emotion regulation, the Mayer-Salovey-Caruso Emotional Intelligence Test -Managing Emotions section- was administered. Finally, a brief neurocognitive assessment was conducted. Results: The GE showed significant poorer performance than the GC in the emotion regulation test as well as in the neurocognitive assessment (p < .05). No correlations were identified between emotion regulation, neurocognition, demographic and clinical data. Discussion and conclusion: Schizophrenia patients show emotion regulation impairment, as well as neurocognitive deficits. Our results are consistent with other studies.

Reduced P3a amplitudes in antipsychotic naïve first-episode psychosis patients and individuals at clinical high-risk for psychosis.

Event related potentials (ERP) associated with early sensory information processing have been proposed as possible vulnerability markers for psychosis. Compared to other ERPs reported in schizophrenia research, like Mismatch Negativity (MMN), little is known about P3a, an ERP related to novelty detection. The aim of this study was to analyze the MMN-P3a complex in 20 antipsychotic naïve first-episode psychosis patients (FEP), 23 antipsychotic naïve individuals at clinical high-risk for psychosis (CHR) and 24 healthy controls. The MMN-P3a amplitudes and latencies were obtained during a passive auditory mismatch frequency deviant ERP paradigm and analyzed in frontal and central scalp regions. There were no significant differences in MMN amplitude between groups. There was a significant group difference in P3a due to reduced amplitude (F[2,64] = 3.7, p = 0.03) in both CHR and FEP groups (Mean difference (MD) = 0.39, p = 0.04 and MD = 0.49, p = 0.02, respectively) compared to the control group and this effect was most prominent on the right side (Group × laterality effect: MD = 0.57, p < 0.01 and MD = 0.58, p < 0.01, respectively). No significant differences were observed for MMN or P3a latencies between groups. Although a P3a decrement in chronic schizophrenia and FEP has been previously reported, our results suggest that this novelty detection impairment is present even in pre-psychosis stages in antipsychotic naïve subjects. This study supports the evidence that P3a could represent a neurophysiological vulnerability marker for the development of psychosis.

[Mismatch Negativity (MMN) and schizophrenia: a revision]. / Mismatch Negativity (MMN) y esquizofrenia: una revisión.

The Mismatch Negativity (MMN) is an auditory Event- Related Potential which is generated as an automatic cerebral response to any change in the auditory stimulation that exceeds a limit corresponding to the discrimination threshold. It has been widely and consistently reported that patients with recent and chronic schizophrenia display smaller MMN amplitudes, suggesting that this component may be related with alteration in sensory memory and stimuli integration capacities, which seem to increase with the disease progression. Recently, new research areas have emerged, and studies of MMN of relatives of patients with schizophrenia have been conducted in order to assess the MMN efficacy as an endophenotype. Likewise, there have been MMN studies in schizophrenia prodromes or clinical high risk subjects, aiming to know if there are cerebral processing disturbances prior to the onset of the disease. The results of these studies have been promising, suggesting the presence of auditory stimuli processing disturbances in this population. These disturbances are subtle and seem to increase as the disease appears. The MMN component may be a very effective electrophysiological tool that provides information about the automatic auditory processing in schizophrenia related to its chronicity. It may also be a relative reliable index of genetic vulnerability and clinical risk for developing schizophrenia. Nevertheless, it is necessary to continue performing studies to get comparable and replicable studies in the future that could confirm the information about MMN utility.