High gamma activity distinguishes frontal cognitive control regions from adjacent cortical networks.

Though the lateral frontal cortex is broadly implicated in cognitive control, functional MRI (fMRI) studies suggest fine-grained distinctions within this region. To examine this question electrophysiologically, we placed electrodes on the lateral frontal cortex in patients undergoing awake craniotomy for tumor resection. Patients performed verbal tasks with a manipulation of attentional switching, a canonical control demand. Power in the high gamma range (70-250 Hz) distinguished electrodes based on their location within a high-resolution fMRI network parcellation of the frontal lobe. Electrodes within the canonical fronto-parietal control network showed increased power in the switching condition, a result absent in electrodes within default mode, language and somato-motor networks. High gamma results contrasted with spatially distributed power decreases in the beta range (12-30 Hz). These results confirm the importance of fine-scale functional distinctions within the human frontal lobe, and pave the way for increased precision of functional mapping in tumor surgeries.

Habilitación de funciones frontales básicas en cardiópatas congénitos a través de LEGO® Education / Basic frontal functions qualification in congenital heart disease with LEGO® Education

Las cardiopatías congénitas se consideran una de las anomalías que alteran la irrigación y el intercambio de oxigenación adecuado a las principales venas y arterias. Esto puede generar consecuencias en el desarrollo neurológico que se puede traducir en retraso psicomotor, déficits de aprendizaje, dificultades académicas y problemas de integración social. Para mejorar los trastornos cognitivos, se propone la habilitación cognitiva basada en los principios de mecánica y robótica de LEGO® Education. El objetivo de este estudio fue medir el efecto de un programa de intervención, basado en el uso de ensamblado y programación robótica con LEGO® Education, sobre las funciones frontales básicas como primera aproximación a un modelo propuesto en pacientes cardiópatas congénitos que han sido sometidos a cirugía cardiovascular. Se trató de un estudio de serie de casos, en el que finalizaron el tratamiento una niña y dos niños con cardiopatías congénitas con RACHS 2 y 3. Se aplicaron sub-escalas BANFE-2 y el cuestionario neuropsicológico de daño frontal antes y después del tratamiento; así como una escala para medir el nivel de ejecución por intervención, durante las ocho sesiones. Los resultados muestran en la escala BANFE2, cambios en las medias de las funciones frontales básicas, de daño leve-moderado y normal a normal alto, principalmente en memoria de trabajo y fluidez verbal. En esta primera aproximación, el método LEGO® Education mostró ser una buena herramienta para la habilitación neuropsicológica de estos pacientes.

Congenital heart diseases are considered to be an anomaly which alter the irrigation and the adequate exchange of oxygenation to the main veins and arteries. They can have neurodevelopmental consequences that could translate into psychomotor retardation, learning deficits, academic difficulties, and social integration problems. Cognitive empowerment based on the mechanics and robotics principles of LEGO® Education is proposed to improve cognitive disorders. In this study, the objective was to measure the effect of an intervention program, based on the use of assembly and robotic programming with LEGO® Education, upon basic frontal functions as a first approach to a proposed model in congenital heart disease patients who have undergone cardiovascular surgery. This was a case-series study, in which a girl and two boys with congenital heart disease with RACHS 2 and 3, completed the treatment. BANFE-2 subscales and the neuropsychological questionnaire of frontal damage were applied before and after the treatment; as well as a scale to measure the level of performance per intervention, through all the eight sessions. The BANFE-2 scale showed changes in the means of frontal functions, from mild-moderate damage and normal to high normal, mainly in working memory and verbal fluency. In this first approach, LEGO® Education method proved to be a useful tool for the neuropsychological empowerment of these patients.

Influencia de la actividad deportiva en el funcionamiento ejecutivo de los lóbulos frontales / Influence of sports activity on executive functioning of the frontal lobes

Esta investigación tuvo como objetivo determinar la influencia de la práctica deportiva sobre el desempeño de las funciones ejecutivas y, a su vez, indagar si la ejecución individual y/o grupal del deporte establece diferencias en el desarrollo de estas habilidades cognitivas y las posibles relaciones asociadas a los tiempos de entrenamiento. Para esto, se estableció una metodología cuantitativa, de diseño comparativo-correlacional. La muestra estuvo conformada por 100 participantes entre 18 y 25 años de edad de ambos géneros, distribuidos en tres grupos, uno de deportes de ejecución individual, otro de deportistas de actividad grupal y un grupo control con personas sin participación en actividades deportivas. Se encontraron, por ejemplo, mayores desempeños en funciones de planeación, memoria de trabajo, control inhibitorio y subtipos de atención por parte de quienes practicaban algún tipo de deporte, independiente de la modalidad de ejecución; pese a que, para algunas funciones cognitivas el participar de un deporte grupal generaba mayores puntuaciones en las tareas propuestas y, en otras, la ventaja la presentaron los integrantes de deportes individuales. Asimismo, se pudo establecer que existe una relación entre el tiempo semanal de entrenamiento y el funcionamiento de la actividad ejecutiva; esto, permitió corroborar la influencia de la actividad deportiva sobre el funcionamiento cognitivo subyacente en los lóbulos frontales.

This research aimed to determine the influence of sports practice on the performance of executive functions and, in turn, to inquire whether the individual and/or group performance of sports establishes differences in the development of these cognitive skills and the possible associated relationships to training times. To do this, a quantitative, comparative-correlational design methodology was established. The sample consisted of 100 participants between 18 and 25 years of age of both genders, divided into three groups, one for individual sports, another for athletes with group activity, and a control group with people without participation in sports activities. For example, greater performance was found in planning functions, working memory, inhibitory control and attention subtypes by those who practiced some type of sport, independent of the execution modality; Despite the fact that, for some cognitive functions, participating in a group sport generated higher scores in the proposed tasks and, in others, the advantage was presented by the members of individual sports. Likewise, it was established that there is a relationship between weekly training time and the performance of executive activity; This allowed to corroborate the influence of sports activity on underlying cognitive functioning on the frontal lobes.

Stimulation of frontal pathways disrupts hand muscle control during object manipulation.

The activity of frontal motor areas during hand-object interaction is coordinated by dense communication along specific white matter pathways. This architecture allows the continuous shaping of voluntary motor output but, despite extensive investigation in non-human primate studies, remains poorly understood in humans. Disclosure of this system is crucial for predicting and treatment of motor deficits after brain lesions. For this purpose, we investigated the effect of direct electrical stimulation on white matter pathways within the frontal lobe on hand-object manipulation. This was tested in 34 patients (15 left hemisphere, mean age 42 years, 17 male, 15 with tractography) undergoing awake neurosurgery for frontal lobe tumour removal with the aid of the brain mapping technique. The stimulation outcome was quantified based on hand-muscle activity required by task execution. The white matter pathways responsive to stimulation with an interference on muscles were identified by means of probabilistic density estimation of stimulated sites, tract-based lesion-symptom (disconnectome) analysis and diffusion tractography on the single patient level. Finally, we assessed the effect of permanent tract disconnection on motor outcome in the immediate postoperative period using a multivariate lesion-symptom mapping approach. The analysis showed that stimulation disrupted hand-muscle activity during task execution at 66 sites within the white matter below dorsal and ventral premotor regions. Two different EMG interference patterns associated with different structural architectures emerged: (i) an 'arrest' pattern, characterized by complete impairment of muscle activity associated with an abrupt task interruption, occurred when stimulating a white matter area below the dorsal premotor region. Local middle U-shaped fibres, superior fronto-striatal, corticospinal and dorsal fronto-parietal fibres intersected with this region. (ii) a 'clumsy' pattern, characterized by partial disruption of muscle activity associated with movement slowdown and/or uncoordinated finger movements, occurred when stimulating a white matter area below the ventral premotor region. Ventral fronto-parietal and inferior fronto-striatal tracts intersected with this region. Finally, only resections partially including the dorsal white matter region surrounding the supplementary motor area were associated with transient upper-limb deficit (P = 0.05; 5000 permutations). Overall, the results identify two distinct frontal white matter regions possibly mediating different aspects of hand-object interaction via distinct sets of structural connectivity. We suggest the dorsal region, associated with arrest pattern and postoperative immediate motor deficits, to be functionally proximal to motor output implementation, while the ventral region may be involved in sensorimotor integration required for task execution.

Hippocampal and thalamic afferents form distinct synaptic microcircuits in the mouse infralimbic frontal cortex.

The selection of goal-directed behaviors is supported by neural circuits located within the frontal cortex. Frontal cortical afferents arise from multiple brain areas, yet the cell-type-specific targeting of these inputs is unclear. Here, we use monosynaptic retrograde rabies mapping to examine the distribution of afferent neurons targeting distinct classes of local inhibitory interneurons and excitatory projection neurons in mouse infralimbic frontal cortex. Interneurons expressing parvalbumin, somatostatin, or vasoactive intestinal peptide receive a large proportion of inputs from the hippocampus, while interneurons expressing neuron-derived neurotrophic factor receive a large proportion of inputs from thalamic regions. A similar dichotomy is present among the four different excitatory projection neurons. These results show a prominent bias among long-range hippocampal and thalamic afferent systems in their targeting to specific sets of frontal cortical neurons. Moreover, they suggest the presence of two distinct local microcircuits that control how different inputs govern frontal cortical information processing.

Distinct Functional and Structural Connectivity of the Human Hand-Knob Supported by Intraoperative Findings.

Fine motor skills rely on the control of hand muscles exerted by a region of primary motor cortex (M1) that has been extensively investigated in monkeys. Although neuroimaging enables the exploration of this system also in humans, indirect measurements of brain activity prevent causal definitions of hand motor representations, which can be achieved using data obtained during brain mapping in tumor patients. High-frequency direct electrical stimulation delivered at rest (HF-DES-Rest) on the hand-knob region of the precentral gyrus has identified two sectors showing differences in cortical excitability. Using quantitative analysis of motor output elicited with HF DES-Rest, we characterized two sectors based on their excitability, higher in the posterior and lower in the anterior sector. We studied whether the different cortical excitability of these two regions reflected differences in functional connectivity (FC) and structural connectivity (SC). Using healthy adults from the Human Connectome Project (HCP), we computed FC and SC of the anterior and the posterior hand-knob sectors identified within a large cohort of patients. The comparison of FC of the two seeds showed that the anterior hand-knob, relative to the posterior hand-knob, showed stronger functional connections with a bilateral set of parietofrontal areas responsible for integrating perceptual and cognitive hand-related sensorimotor processes necessary for goal-related actions. This was reflected in different patterns of SC between the two sectors. Our results suggest that the human hand-knob is a functionally and structurally heterogeneous region organized along a motor-cognitive gradient.SIGNIFICANCE STATEMENT The capability to perform complex manipulative tasks is one of the major characteristics of primates and relies on the fine control of hand muscles exerted by a highly specialized region of the precentral gyrus, often termed the "hand-knob" sector. Using intraoperative brain mapping, we identify two hand-knob sectors (posterior and anterior) characterized by differences in cortical excitability. Based on resting-state functional connectivity (FC) and tractography in healthy subjects, we show that posterior and anterior hand-knob sectors differ in their functional connectivity (FC) and structural connectivity (SC) with frontoparietal regions. Thus, anteroposterior differences in cortical excitability are paralleled by differences in FC and SC that likely reflect a motor (posterior) to cognitive (anterior) organization of this cortical region.

Axono-cortical evoked potentials as a new method of IONM for preserving the motor control network: a first study in three cases.

BACKGROUND: White matter stimulation in an awake patient is currently the gold standard for identification of functional pathways. Despite the robustness and reproducibility of this method, very little is known about the electrophysiological mechanisms underlying the functional disruption. Axono-cortical evoked potentials (ACEPs) provide a reliable technique to explore these mechanisms. OBJECTIVE: To describe the shape and spatial patterns of ACEPs recorded when stimulating the white matter of the caudal part of the right superior frontal gyrus while recording in the precentral gyrus. METHODS: We report on three patients operated on under awake condition for a right superior frontal diffuse low-grade glioma. Functional sites were identified in the posterior wall of the cavity, whose 2-3-mA stimulation generated an arrest of movement. Once the resection was done, axono-cortical potentials were evoked: recording electrodes were put over the precentral gyrus, while stimulating at 1 Hz the white matter functional sites during 30-60 s. Unitary evoked potentials were averaged off-line. Waveform was visually analyzed, defining peaks and troughs, with quantitative measurements of their amplitudes and latencies. Spatial patterns of ACEPs were compared with patients' own and HCP-derived structural connectomics. RESULTS: Axono-cortical evoked potentials (ACEPs) were obtained and exhibited complex shapes and spatial patterns that correlated only partially with structural connectivity patterns. CONCLUSION: ACEPs is a new IONM methodology that could both contribute to elucidate the propagation of neuronal activity within a distributed network when stimulating white matter and provide a new technique for preserving motor control abilities during brain tumor resections.

Association between brain morphometry and aerobic fitness level and sex in healthy emerging adults.

OBJECTIVE: Aerobic fitness may be beneficial for neuroanatomical structure. However, few have investigated this in emerging adults while also accounting for potential sex differences. Here we examine aerobic fitness level, sex, and their interaction in relation to cortical thickness, surface area, and volume. METHOD: Sixty-three young adults between the ages of 16-26 were balanced for sex and demonstrated a wide range of aerobic fitness levels. Exclusion criteria included left-handedness, past-year independent Axis-I disorders, major medical/neurologic disorders, prenatal medical issues, prenatal alcohol/illicit drug exposure, or excessive substance use. Participants completed an MRI scan and a graded exercise test to volitional fatigue (VO2 max). Data analyses were run in Freesurfer and data was corrected for multiple comparisons with Monte Carlo simulations at .05. RESULTS: Males demonstrated higher VO2 values. Higher VO2 values were statistically independently related to thinner lateral occipital, superior parietal, cuneus, precuneus, and inferior parietal regions, smaller lateral occipital volume, and larger inferior parietal surface area. Compared to females, males had larger volume in rostral anterior cingulate, lateral occipital, and superior frontal regions, and greater surface area in fusiform, inferior parietal, rostral and caudal anterior cingulate, and superior parietal regions. VO2*Sex interactions revealed higher-fit females had higher inferior parietal, paracentral, and supramarginal surface area, while lower-fit males showed larger surface area in these same regions. CONCLUSIONS: Individuals with higher aerobic fitness performance had thinner cortices, lower volume, and larger surface area in sensorimotor regions than lower fit individuals, perhaps suggesting earlier neuromaturation in higher fit individuals. Larger surface area was associated with higher-fit females and lower-fit males. Thus both sex and aerobic fitness are important in shaping brain health in emerging adults.

Value Neglect: A Critical Role for Ventromedial Frontal Lobe in Learning the Value of Spatial Locations.

Whether you are a gazelle bounding to the richest tract of grassland or a return customer heading to the freshest farm stand at a crowded market, the ability to learn the value of spatial locations is important in adaptive behavior. The ventromedial frontal lobe (VMF) is implicated in value-based decisions between objects and in flexibly learning to choose between objects based on feedback. However, it is unclear if this region plays a material-general role in reward learning. Here, we tested whether VMF is necessary for learning the value of spatial locations. People with VMF damage were compared with healthy participants and a control group with frontal damage sparing VMF in an incentivized spatial search task. Participants chose among spatial targets distributed among distractors, rewarded with an expected value that varied along the right-left axis of the screen. People with VMF damage showed a weaker tendency to reap reward in contralesional hemispace. In some individuals, this impairment could be dissociated from the ability to make value-based decisions between objects, assessed separately. This is the first evidence that the VMF is critically involved in reward-guided spatial search and offers a novel perspective on the relationships between value, spatial attention, and decision-making.

Neural Basis of Smoking-Related Difficulties in Emotion Regulation.

BACKGROUND: Negative emotional states contribute to cigarette smoking, and difficulties in regulating these states can hinder smoking cessation. Understanding the neural bases of these difficulties in smokers may facilitate development of novel therapies for Tobacco Use Disorder. METHODS: Thirty-seven participants (18 smokers, 19 nonsmokers; 16-21 years old) completed the Difficulties in Emotion Regulation Scale (DERS), which is comprised of 6 subscales (lack of emotional clarity, lack of emotional awareness, limited access to emotion regulation strategies, nonacceptance of emotional responses, difficulties engaging in goal-directed behaviors, and impulse control difficulties) that combine to provide a total score. Participants also underwent functional magnetic resonance imaging to determine resting-state functional connectivity of the amygdala. Separate ANOVAs were used to determine group differences in self-reports on the DERS. Voxel-wise linear mixed models were performed to determine whether group influenced relationships between whole-brain functional connectivity of the amygdala and scores on the DERS. RESULTS: Compared with nonsmokers, smokers reported greater difficulties in emotion regulation, denoted by higher total scores on the DERS. Group differences were observed on a subscale of lack of emotional clarity, but no other subscale differences on the DERS were observed. Nonsmokers exhibited a greater negative correlation than smokers between lack of emotional clarity scores and connectivity of the amygdala with the left inferior frontal gyrus. Finally, this amygdala-to-left inferior frontal gyrus connectivity was weaker in smokers than in nonsmokers. CONCLUSIONS: These findings suggest that difficulties in emotion regulation in smokers are at least partially due to lack of emotional clarity. Given the role of the inferior frontal gyrus in understanding emotional states, strengthening connectivity between the amygdala and the inferior frontal gyrus may improve emotional clarity to help smokers regulate their negative emotions, thereby improving their ability to quit smoking.

Does the superior fronto-occipital fascicle exist in the human brain? Fiber dissection and brain functional mapping in 90 patients with gliomas.

The presence of the superior fronto-occipital fascicle (SFOF) has been reported in the Rhesus monkey; however, it is a subject of controversy in humans. The aim of this study is to identify the SFOF using both in vitro and in vivo anatomo-functional analyses. This study consisted of two approaches. First, one acallosal brain and 12 normal postmortem hemispheres (five left and seven right sides) were dissected under a microscope using Klingler's fiber dissection technique. We focused on the medial subcallosal area superior to the Muratoff bundle, which has been indicated as a principal target area of the SFOF in previous studies. Second, 90 patients underwent awake craniotomy for gliomas with direct electrical stimulations. Functional examinations for visual, ataxic, and cognitive tasks were performed and 453 positive mapping sites were investigated by voxel-based morphometry analysis to establish the functions of the SFOF. The corticostriatal fibers, or the Muratoff bundle, and thalamic peduncle fibers joined in the area of the caudate nucleus, making thalamic peduncle/ corticostriatal bundles, which ran antero-posteriorly in the anterior subcallosal area and radiated from the caudate superior margin in the posterior subcallosal area. However, no SFOF fiber bundle crossed perpendicular to the thalamic peduncle/ corticostriatal bundles in the posterior subcallosal area. In the acallosal hemispheres, Probst bundles were confirmed and the subcallosal areas did not show a specific organization different from the normal brain. Hence, we could not detect a long and continuous association fascicle connecting the frontal lobe and occipital or parietal lobe in the target areas. Furthermore, in the in vivo functional mappings of awake surgery and voxel-based morphometry analysis, eight positive points on the SFOF were selected from the total 453 positive points, but their functions were not related with visual processing and spatial awareness, as has been reported in previous studies. In conclusion, in the present study we attempted to investigate the existence of the SFOF using an anatomical and functional approach. According to our results, the SFOF may not exist in the human brain.

Hemispheric Dominance for Language and Side Effects in Mapping the Inferior Frontal Junction Area with Transcranial Magnetic Stimulation.

BACKGROUND AND STUDY AIMS: Language mapping by navigated transcranial magnetic stimulation (TMS) is commonly applied over the left language-dominant hemisphere to indicate the language-related cortex. Detailed language mapping of Broca's region including stimulation targets in the immediate vicinity to the premotor cortex may raise concern about confounding unspecific motor effects. We performed interhemispheric comparisons to delineate such possible unspecific effects from true TMS-induced language inhibition. MATERIAL AND METHODS: Fifteen healthy German speakers named object pictures during navigated TMS over a left- and right-hemispheric target array covering the left inferior frontal junction area. Six mapping repetitions were conducted per hemisphere. Order of stimulation side was randomized between participants. Self-rating of discomfort was assessed after each stimulation; language errors and motor side effects were evaluated offline. RESULTS: Naming errors were observed significantly more frequently during left- than right-hemispheric stimulation. The same pattern was found for the most frequent error category of performance errors. Hierarchical cluster analyses of normalized ratings of error severity revealed a clear focus of TMS susceptibility for language inhibition in object naming at the dorsoposterior target sites only in the left hemisphere. We found no statistical difference in discomfort ratings between both hemispheres and also no interhemispheric difference in motor side effects, but we observed significantly stronger muscle contractions of the eyes as compared with the mouth. CONCLUSION: Our results of (1) unspecific pre-/motor effects similarly induced in both hemispheres, and (2) a specific focus of TMS susceptibility in the language-dominant hemisphere render any substantial contribution of nonlanguage-specific effects in TMS language mapping of the inferior frontal junction area highly unlikely.

Mapping neural dynamics underlying saccade preparation and execution and their relation to reaction time and direction errors.

Our ability to control and inhibit automatic behaviors is crucial for negotiating complex environments, all of which require rapid communication between sensory, motor, and cognitive networks. Here, we measured neuromagnetic brain activity to investigate the neural timing of cortical areas needed for inhibitory control, while 14 healthy young adults performed an interleaved prosaccade (look at a peripheral visual stimulus) and antisaccade (look away from stimulus) task. Analysis of how neural activity relates to saccade reaction time (SRT) and occurrence of direction errors (look at stimulus on antisaccade trials) provides insight into inhibitory control. Neuromagnetic source activity was used to extract stimulus-aligned and saccade-aligned activity to examine temporal differences between prosaccade and antisaccade trials in brain regions associated with saccade control. For stimulus-aligned antisaccade trials, a longer SRT was associated with delayed onset of neural activity within the ipsilateral parietal eye field (PEF) and bilateral frontal eye field (FEF). Saccade-aligned activity demonstrated peak activation 10ms before saccade-onset within the contralateral PEF for prosaccade trials and within the bilateral FEF for antisaccade trials. In addition, failure to inhibit prosaccades on anti-saccade trials was associated with increased activity prior to saccade onset within the FEF contralateral to the peripheral stimulus. This work on dynamic activity adds to our knowledge that direction errors were due, at least in part, to a failure to inhibit automatic prosaccades. These findings provide novel evidence in humans regarding the temporal dynamics within oculomotor areas needed for saccade programming and the role frontal brain regions have on top-down inhibitory control.

Progesterone modulates theta oscillations in the frontal-parietal network.

The neuroactive metabolites of the steroid hormones progesterone (P4) and testosterone (T) are GABAergic modulators that influence cognition, yet, the specific effect of P4 and T on brain network activity remains poorly understood. Here, we investigated if a fundamental oscillatory network activity pattern, often related to cognitive control, frontal midline theta (FMT) oscillations, are modulated by steroids hormones, P4 and T. We measured the concentration of P4 and T using salivary enzyme immunoassay and FMT oscillations using high-density electroencephalography (EEG) during eyes-open resting-state in 55 healthy women and men. Electrical brain activity was analyzed using Fourier analysis, aperiodic signal fitting, and beamformer source localization. Steroid hormone concentrations and biological sex were used as predictors for scalp and source-estimated amplitude of theta oscillations. Elevated concentrations of P4 predicted increased amplitude of FMT oscillations across both sexes, and no relationship was found with T. The positive correlation with P4 was specific to the frontal midline electrodes and survived correction for the background aperiodic signal of the brain. Using source localization, FMT oscillations were localized to the frontal-parietal network (FPN). Additionally, theta amplitude within the FPN, but not the default mode network, positively correlated with P4 concentration. Our results suggest that P4 concentration modulates brain activity via upregulation of theta oscillations in the FPN.

Large scale networks for human hand-object interaction: Functionally distinct roles for two premotor regions identified intraoperatively.

The development of awake intraoperative brain-mapping procedures for resection of brain tumors is of growing interest in neuroscience, because it enables direct testing of brain tissue, previously only possible in non-human primates. In a recent study performed in this setting specific effects can be induced by direct electrical stimulation on different sectors of premotor cortex during the execution of a hand manipulation task. Specifically, direct electrical stimulation applied on a dorsal sector of precentral cortex led to an increase in motor unit recruitment in hand muscles during execution of a hand manipulation task (Recruitment sector). The opposite effect was elicited when electrical stimulation was delivered more ventrally on the precentral cortex (Suppression sector). We studied whether the different effects on motor behavior induced by direct electrical stimulation applied on the two sites of the precentral cortex underlie differences in their functional connectivity with other brain areas, measured using resting state fMRI. Using healthy adults scanned as part of the Human Connectome Project, we computed the functional connectivity of each sector used as seeds. The functional connectivity patterns of the two intraoperative seeds was similar but cross-comparison revealed that the left and right Recruitment sectors had stronger functional connections with the hand region of the sensorimotor cortex, while the right Suppression region displayed stronger functional connectivity with a bilateral set of parieto-frontal areas crucial for the integration of perceptual and cognitive hand-related sensorimotor processes required for goal-related hand actions. Our results suggest that analyzing data obtained in the intraoperative setting with resting state functional magnetic resonance imaging in healthy brains can yield useful insight into the roles of different premotor sectors directly involved in hand-object interaction.

Electroconvulsive Seizures Induce Autophagy by Activating the AMPK Signaling Pathway in the Rat Frontal Cortex.

BACKGROUND: It is uncertain how electroconvulsive therapy-induced generalized seizures exert their potent therapeutic effects on various neuropsychiatric disorders. Adenosine monophosphate-activated protein kinase (AMPK) plays a major role in maintaining metabolic homeostasis and activates autophagic processes via unc-51-like kinase (ULK1). Evidence supports the involvement of autophagy system in the action mechanisms of antidepressants and antipsychotics. The effect of electroconvulsive therapy on autophagy-related signaling requires further clarification. METHODS: The effect of electroconvulsive seizure on autophagy and its association with the AMPK signaling pathway were investigated in the rat frontal cortex. Electroconvulsive seizure was provided once per day for 10 days (E10X), and compound C or 3-methyadenine was administered through an intracerebroventricular cannula. Molecular changes were analyzed with immunoblot, immunohistochemistry, and transmission electron microscopy analyses. RESULTS: E10X increased p-Thr172-AMPKα immunoreactivity in rat frontal cortex neurons. E10X increased phosphorylation of upstream effectors of AMPK, such as LKB1, CaMKK, and TAK1, and of its substrates, ACC, HMGR, and GABABR2. E10X also increased p-Ser317-ULK1 immunoreactivity. At the same time, LC3-II and ATG5-ATG12 conjugate immunoreactivity increased, indicating activation of autophagy. An intracerebroventricular injection of the AMPK inhibitor compound C attenuated the electroconvulsive seizure-induced increase in ULK1 phosphorylation as well as the protein levels of LC3-II and Atg5-Atg12 conjugate. Transmission electron microscopy clearly showed an increased number of autophagosomes in the rat frontal cortex after E10X, which was reduced by intracerebroventricular treatment with the autophagy inhibitor 3-methyadenine and compound C. CONCLUSIONS: Repeated electroconvulsive seizure treatments activated in vivo autophagy in the rat frontal cortex through the AMPK signaling pathway.

Immersing Patients in a Virtual Reality Environment for Brain Mapping During Awake Surgery: Safety Study.

BACKGROUND: Brain mapping by direct electrical stimulation during awake craniotomy is now a standard procedure that reduces the risk of permanent neurologic deficits. Virtual reality technology immerses the patient in a virtually controlled, interactive world, offering a unique opportunity to develop innovative tasks for perioperative mapping of complex cognitive functions. The objective of this prospective single-center study was to evaluate the tolerance and safety of a virtual reality headset (VRH) and immersive virtual experiences in patients undergoing awake craniotomy and brain mapping by direct electrical stimulation. METHODS: The study included 30 patients with a brain tumor near the language area. Language mapping was performed with a naming task, DO 80, presented on a digital tablet and then in two-dimensional and three-dimensional formats through a VRH. During wound closure, different virtual reality experiences were proposed to the patient, offering different types of virtual motion or interaction with an avatar piloted by a neuropsychologist. RESULTS: Two patients could not use the VRH owing to technical issues. No procedure was aborted, no patient experienced virtual reality sickness and all patients reported they would repeat the procedure. Despite a high rate of intraoperative focal seizures, there was no argument to attribute the seizures to VRH use. CONCLUSIONS: This study shows that it is possible during awake brain surgery to immerse the patient in a virtual environment and to interact with the patient, opening the field of new brain mapping procedures for complex cognitive functions.

Neural correlates of improvements in personality and behavior following a neurological event.

Research on changes in personality and behavior following brain damage has focused largely on negative outcomes, such as increased irritability, moodiness, and social inappropriateness. However, clinical observations suggest that some patients may actually show positive personality and behavioral changes following a neurological event. In the current work, we investigated neuroanatomical correlates of positive personality and behavioral changes following a discrete neurological event (e.g., stroke, benign tumor resection). Patients (N = 97) were rated by a well-known family member or friend on five domains of personality and behavior: social behavior, irascibility, hypo-emotionality, distress, and executive functioning. Ratings were acquired during the chronic epoch of recovery, when psychological status was stabilized. We identified patients who showed positive changes in personality and behavior in one or more domains of functioning. Lesion analyses indicated that positive changes in personality and behavior were most consistently related to damage to the bilateral frontal polar regions and the right anterior dorsolateral prefrontal region. These findings support the conclusion that improvements in personality and behavior can occur after a neurological event, and that such changes have systematic neuroanatomical correlates. Patients who showed positive changes in personality and behavior following a neurological event were rated as having more disturbed functioning prior to the event. Our study may be taken as preliminary evidence that improvements in personality and behavior following a neurological event may involve dampening of (premorbidly) more extreme expressions of emotion.

Region-specific adenosinergic modulation of the slow-cortical rhythm in urethane-anesthetized rats.

Slow cortical rhythm (SCR) is a rhythmic alternation of UP and DOWN states during sleep and anesthesia. SCR-associated slow waves reflect homeostatic sleep functions. Adenosine accumulating during prolonged wakefulness and sleep deprivation (SD) may play a role in the delta power increment during recovery sleep. NREM sleep is a local, use-dependent process of the brain. In the present study, direct effect of adenosine on UP and DOWN states was tested by topical application to frontal, somatosensory and visual cortices, respectively, in urethane-anesthetized rats. Local field potentials (LFPs) were recorded using an electrode array inserted close to the location of adenosine application. Multiple unit activity (MUA) was measured from layer V-VI in close proximity of the recording array. In the frontal and somatosensory cortex, adenosine modulated SCR with slow kinetics on the LFP level while MUA remained mostly unaffected. In the visual cortex, adenosine modulated SCR with fast kinetics. In each region, delta power increment was based on the increased frequency of state transitions as well as increased height of UP-state associated slow waves. These results show that adenosine may directly modulate SCR in a complex and region-specific manner which may be related to the finding that restorative processes may take place with varying duration and intensity during recovery sleep in different cortical regions. Adenosine may play a direct role in the increment of the slow wave power observed during local sleep, furthermore it may shape the region-specific characteristics of the phenomenon.

Funciones ejecutivas y ajuste clínico en adolescentes colombianos policonsumidores / Executive functions and clinical adjustment in Colombian adolescents polydrug

Resumen El estudio tuvo como objetivo analizar el funcionamiento ejecutivo y el ajuste clínico en una muestra de adolescentes colombianos policonsumidores. Se efectuó un estudio ex post facto con 204 participantes entre 12 y 17 años (M = 14,50, DT = 1,71). Se aplicó la Batería Neuropsicológica de Funciones Ejecutivas y Lóbulos Frontales BANFE-2 y para la evaluación clínica se utilizó la Escala de Autoestima de Rosenberg, Cuestionario de Afrontamiento COPE, Escala de Impulsividad de Dickman y Cuestionario de 90 Síntomas SCL-90-R. Se identificó un rendimiento significativamente inferior del grupo policonsumidor en las funciones ejecutivas, bajos niveles de autoestima, altos niveles de impulsividad disfuncional y de diversidad psicopatológica, así como estilo de afrontamiento a través del consumo de sustancias. Así mismo, se detectó un efecto predictor de la interacción edad x tiempo de consumo en el funcionamiento ejecutivo, observándose un menor rendimiento de los policonsumidores más jóvenes a medida que se incrementaba el tiempo de consumo.

Abstract The research aim was to analyze the executive functioning and the clinical adjustment in a sample of Colombian teen polydrug users. An ex post facto study was carried out with 204 participants, 12-17 years old (M= 14,50, SD = 1,71). The neuropsychological test BANFE-2 was applied for analyzing frontal lobes and executive functioning and the Rosenberg self esteem scale, a COPE questionnaire, the Dickman impulsivity scale and the SCL-90-R questionnaire were used for clinical adjustment respectively. A lower executive functioning throughput were observed in polydrug users. Low self-esteem, high dysfunctional impulsivity, high diverse psychopathologies and coping strategies for drug use were also observed. A predictor effect between age and consumption time on the executive functioning were also determined. A lower throughput in younger polydrug users increase through consumption time.