Perfiles de actividad magnética cerebral de jóvenes con consumo intensivo de alcohol

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Psicología, leída el 24-01-2017El patrón de consumo de alcohol binge drinking se caracteriza por la ingesta intermitente de grandes cantidades del alcohol en un corto espacio de tiempo alternándose con periodos de abstinencia. En España, este tipo de consumo de alcohol se asocia al conocido efecto botellón en el que los jóvenes se reúnen en espacios públicos, principalmente los fines de semana, teniendo el alcohol como protagonista. La adolescencia, edad en la que se inicia este tipo de consumo, es considerada un periodo crítico de desarrollo en el que el cerebro experimenta grandes cambios madurativos, fundamentalmente en los lóbulos frontales. Dada su inmadurez, el cerebro adolescente muestra mayor vulnerabilidad ante el efecto neurotóxico del alcohol que el cerebro adulto. Debido a la alta prevalencia que este tipo de consumo presenta entre los jóvenes, la comunidad científica ha mostrado interés en las últimas décadas por estudiar las posibles consecuencias que puede tener en la estructura y funcionamiento del cerebro de jóvenes que beben de este modo. Sin embargo, hasta el momento no existían estudios que evaluasen el efecto del binge drinking en la actividad magnética cerebral. La Magnetoencefalografía es una técnica no invasiva que mide las corrientes magnéticas generadas por las pequeñas corrientes neurales que producen las neuronas. La presente tesis ha utilizado esta técnica a lo largo de los tres experimentos en los que se estudió: 1) la actividad magnética cerebral en el espacio de los sensores asociada del estado de reposo de jóvenes universitarios de 18-19 años con el patrón binge drinking y un grupo control, 2) la actividad magnética cerebral en espacio de las fuentes del estado de reposo y la conectividad estructural de los mismos jóvenes dos años más tarde, con 20-21 años; y 3) la actividad magnética cerebral en espacio de las fuentes asociada a una tarea Go/NoGo de los mismos jóvenes durante la primera fase del estudio, cuando tenían 18-19 años...The alcohol consumption binge drinking pattern is characterized by intermittent intake of large amounts of alcohol in a short space of time, alternated with periods of abstinence. In Spain, this type of alcohol consumption is associated with the well-known “efecto botellón” where young people gather in public spaces, especially on weekends, having the alcohol as the protagonist. Adolescence, the age in which this type of consumption begins, is considered a critical period of neural development in which the brain undergoes maturational changes, mainly in the frontal lobes. Given its immaturity, adolescent brain is more vulnerable to the neurotoxic effects of alcohol than the adult brain. Because of its high prevalence among young adolescents, since last decades the scientific community has shown increasing interest to study the possible consequences that binge drinking may have on the structure and functioning of the brain. However, so far there are no studies assessing the effect of binge drinking with Magnetoencephalography. Magnetoencephalography is a noninvasive technique that measures the magnetic currents generated by neural currents produced by pyramidal neurons. The present dissertation has used this technique over the three experiments, studying: 1) brain magnetic activity in the sensor space associated to resting state of university students of aged 18-19 years old with alcohol binge drinking pattern and also a control group, 2) brain magnetic activity in the source space also associated to resting state and structural connectivity of the same young students two years later, with 20-21 years old; and finally, 3) the brain magnetic activity in source space associated with a Go/NoGo task in the first phase of the study, when the participants were 18-19...Fac. de PsicologíaTRUEunpu

Drug polyconsumption is associated with increased synchronization of brain electrical-activity at rest and in a counting task

Drug abusers typically consume not just one but several types of drugs, starting from alcohol and marijuana consumption, and then dramatically lapsing into addiction to harder drugs, such as cocaine, heroin, or amphetamine. The brain of drug abusers presents various structural and neurophysiological abnormalities, some of which may predate drug consumption onset. However, how these changes translate into modifications in functional brain connectivity is still poorly understood. To characterize functional connectivity patterns, we recorded Electroencephalogram (EEG) activity from 21 detoxified drug abusers and 20 age-matched control subjects performing a simple counting task and at rest activity. To evaluate the cortical brain connectivity network we applied the Synchronization Likelihood algorithm. The results showed that drug abusers had higher synchronization levels at low frequencies, mainly in the θ band (4–8 Hz) between frontal and posterior cortical regions. During the counting task, patients showed increased synchronization in the β (14–35 Hz), and γ (35–45 Hz) frequency bands, in fronto-posterior and interhemispheric temporal regions. Taken together 'slow-down' at rest and task-related 'over-exertion' could indicate that the brain of drug abusers is suffering from a premature form of ageing. Future studies will clarify whether this condition can be reversed following prolonged periods of abstinence

The Interplay of Cognitive Load Theory and Attentional Bias in Heroin Addiction

Background: Current theories of addictive behavior suggest that individuals using heroin and other substances often exhibit an Attentional Bias (AB) towards environmental cues associated with substance consumption. Methods: This study aimed to assess AB in individuals with a history of substance dependence, specifically heroin users, utilizing Lavie's cognitive load theory (1995). Participants were categorized into a treatment group (TG), an abstinent group (AG), and a non-consumer group (NCG). An attentional task was designed based on Lavie's model, involving discriminating target letters (X or N) presented alone (low cognitive load, LCL), or among other letters (high cognitive load, HCL). Results: According to Lavie's model (1995), it was anticipated that in the TG and AG groups, compared to the NCG, AB would manifest only in the LCL condition. No significant differences were found regarding AB towards consumption-related images (i.e., emotional images) compared to neutral stimuli in the LCL condition. Conclusion: Our study did not find statistically significant results concerning AB between the TG and the AG when compared to the NCG. These findings contradict a significant body of research investigating selective attention in individuals with addiction, which consistently observed AB within this population

Binge drinking affects brain oscillations linked to motor inhibition and execution

Neurofunctional studies have shown that binge drinking patterns of alcohol consumption during adolescence and youth are associated with anomalies in brain functioning. Recent evidence suggests that event-related oscillations may be an appropriate index of neurofunctional damage associated with alcoholism. However, there is no study to date that has evaluated the effects of binge drinking on oscillatory brain responses related to task performance. The purpose of the present study was to examine brain oscillations linked to motor inhibition and execution in young binge drinkers (BDs) compared with age-matched controls.Methods:Electroencephalographic activity was recorded from 64 electrodes while 72 university students (36 controls and 36 BDs) performed a visual Go/NoGo task. Event-related oscillations along with the Go-P3 and NoGo-P3 event-related potential components were analysed. Results:While no significant differences between groups were observed regarding event-related potentials, event-related oscillation analysis showed that BDs displayed a lower oscillatory response than controls in delta and theta frequency ranges during Go and NoGo conditions.Conclusions:Findings are congruent with event-related oscillation studies showing reduced delta and/or theta oscillations in alcoholics during Go/NoGo tasks. Thus, BDs appear to show disruptions in neural oscillations linked to motor inhibition and execution similar to those observed in alcohol-dependent subjects. Finally, these results are the first to evidence that oscillatory brain activity may be a sensitive indicator of underlying brain anomalies in young BDs, which could complement standard event-related potential measures.Depto. de Psicología Experimental, Procesos Cognitivos y LogopediaFac. de PsicologíaTRUEpu

Exploratory Analysis of Power Spectrum and Functional Connectivity During Resting State in Young Binge Drinkers: A MEG Study

Binge Drinking (BD) is a pattern of intermittent intensive alcohol intake which has spread among young adults over the last decades. Adolescence constitutes a critical neuromaturation period in which the brain is particularly sensitive to the effects of alcohol. However, little is known about how BD affects the brain activity. This study aimed to characterize the brain's functional organization in BD and non-BD young population by means of analyzing functional connectivity (FC) and relative power spectra (PS) profiles measured with magnetoencephalography (MEG) during eyes-closed resting state. Our sample composed 73 first-year university students (35 BDs and 38 controls). Results showed that the BD subjects displayed a decreased alpha FC in frontal-parietal regions, and conversely, an enhanced FC in the delta, theta and beta bands in fronto-temporal networks. Besides the FC differences, the BD group showed a decreased PS within alpha range and an increased PS within theta range in the brain's occipital region. These differences in FC and PS measurements provide new evidence of the neurophysiological alterations related to the alcohol neurotoxicity and could represent an initial sign of an anomalous neural activity caused by a BD pattern of alcohol consumption during youth.Depto. de Psicología Experimental, Procesos Cognitivos y LogopediaFac. de PsicologíaTRUEpu

Abnormal organization of inhibitory control functional networks in future binge drinkers

Background and aims Adolescent Binge drinking has become an increasing health and social concern, which cause several detrimental consequences for brain integrity. However, research on neurophysiological traits of vulnerability for binge drinking predisposition is limited at this time. In this work, we conducted a two-year longitudinal study with magnetoencephalography (MEG) over a cohort of initially alcohol-naive adolescents with the purpose of characterize inhibitory cortical networks’ anomalies prior to alcohol consumption onset in those youths who will transit into binge drinkers years later. Methods Sixty-seven participant’s inhibitory functional networks, and dysexecutive/impulsivity traits were measured by means of inhibitory task (go/no-go) and questionnaires battery. After a follow-up period of two years, we evaluated their alcohol consumption habits, sub-dividing them in two groups according to their alcohol intake patterns: future binge drinkers (fBD): n = 22; future Light/non-drinkers (fLD): n = 17. We evaluated whole-brain and seed-based functional connectivity profiles, as well as its correlation with impulsive and dysexecutive behaviours, searching for early abnormalities before consumption onset. Results For the first time, abnormalities in MEG functional networks and higher dysexecutive and impulsivity profiles were detected in alcohol-naïve adolescents who two years later became binge drinkers. Concretely, fBD exhibit a distinctive pattern of beta band hyperconnectivity among crucial regions of inhibitory control networks, positively correlated with behavioral traits and future alcohol intake rate. Conclusions These findings strongly support the idea of early neurobiological vulnerabilities for substances consumption initiation, with inhibitory functional networks’ abnormalities as a relevant neurophysiological marker of subjects at risk— we hypothesize this profile is due to neurodevelopmental and neurobiological differences involving cognitive control networks and neurotransmission pathways.Ministerio de SanidadComunidad de MadridUCM-SantanderDepto. de Psicología Experimental, Procesos Cognitivos y LogopediaDepto. de Radiología, Rehabilitación y FisioterapiaFac. de PsicologíaFac. de MedicinaFac. de EducaciónTRUEpu

Functional and structural brain connectivity of young binge drinkers: a follow-up study

Adolescence is a period of ongoing brain maturation characterized by hierarchical changes in the functional and structural networks. For this reason, the young brain is particularly vulnerable to the toxic effects of alcohol. Nowadays, binge drinking is a pattern of alcohol consumption increasingly prevalent among adolescents. The aim of the present study is to evaluate the evolution of the functional and anatomical connectivity of the Default Mode Network (DMN) in young binge drinkers along two years. Magnetoencephalography signal during eyes closed resting state as well as Diffusion Tensor Imaging (DTI) were acquired twice within a 2-year interval from 39 undergraduate students (22 controls, 17 binge drinkers) with neither personal nor family history of alcoholism. The group comparison showed that, after maintaining a binge drinking pattern along at least two years, binge drinkers displayed an increased brain connectivity of the DMN in comparison with the control group. On the other hand, the structural connectivity did not show significant differences neither between groups nor over the time. These findings point out that a continued pattern of binge drinking leads to functional alterations in the normal brain maturation process, even before anatomical changes can be detected.Depto. de Psicología Experimental, Procesos Cognitivos y LogopediaFac. de PsicologíaTRUEpu

Drug polyconsumption is associated with increased synchronization of brain electrical-activity at rest and in a counting task

Drug abusers typically consume not just one but several types of drugs, starting from alcohol and marijuana consumption, and then dramatically lapsing into addiction to harder drugs, such as cocaine, heroin, or amphetamine. The brain of drug abusers presents various structural and neurophysiological abnormalities, some of which may predate drug consumption onset. However, how these changes translate into modifications in functional brain connectivity is still poorly understood. To characterize functional connectivity patterns, we recorded Electroencephalogram (EEG) activity from 21 detoxified drug abusers and 20 age-matched control subjects performing a simple counting task and at rest activity. To evaluate the cortical brain connectivity network we applied the Synchronization Likelihood algorithm. The results showed that drug abusers had higher synchronization levels at low frequencies, mainly in the θ band (4–8 Hz) between frontal and posterior cortical regions. During the counting task, patients showed increased synchronization in the β (14–35 Hz), and γ (35–45 Hz) frequency bands, in fronto-posterior and interhemispheric temporal regions. Taken together 'slow-down' at rest and task-related 'over-exertion' could indicate that the brain of drug abusers is suffering from a premature form of ageing. Future studies will clarify whether this condition can be reversed following prolonged periods of abstinence.Depto. de Psicología Experimental, Procesos Cognitivos y LogopediaFac. de PsicologíaTRUEpu

Young alcohol binge drinkers have elevated blood endotoxin, peripheral inflammation and low cortisol levels: neuropsychological correlations in women

Alcohol binge drinking is a pattern of heavy alcohol consumption that is increasingly practiced by adolescents and young adults. Evidence indicates that alcohol binges induce peripheral inflammation and an exacerbated neuroimmune response that may participate in alcohol‐induced cognitive/behavioral dysfunctions. Here, we recruited 20‐year‐old male and female university students who were identified as binge drinkers for at least 2 years. Compared with controls, young alcohol binge drinkers had elevated levels of blood endotoxin and upregulated markers of the toll‐like receptor 4/NF‐κB inflammatory pathway in peripheral blood mononuclear cells, together with pro‐inflammatory cytokine/chemokine release, oxidative stress and lipid peroxidation. These changes positively correlate with the estimated blood alcohol levels achieved during alcohol binge intoxication and negatively correlate with the time elapsed from the last alcohol consumption. The immune/inflammatory changes were more prominent in female drinkers, who showed elevated levels of alcohol danger‐associated molecules, such as high mobility group box 1, indicating that there are sex‐related differences in the peripheral inflammatory response to alcohol. In contrast, cortisol levels were decreased in alcohol binge drinkers. Finally, higher levels of inflammatory markers, mainly monocyte chemoattractant protein‐1, as well as LPS, high mobility group box 1, toll‐like receptor 4, IL‐6 and ciclooxygenase‐2, correlated with worse scores on episodic memory and executive functioning tasks in female binge drinkers but not in male binge drinkers. These results emphasize possible risky consequences of alcohol use in binge episodes during young adulthood and call attention to sex‐related differences in the alcohol‐induced immune/inflammatory and neurocognitive responses.Depto. de Psicología Experimental, Procesos Cognitivos y LogopediaFac. de PsicologíaTRUEpu