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La corteza prefrontal medial controla el alerta conductual y vegetativo: Implicancias en desórdenes de la conducta
Valdés G,José Luis; Torrealba L,Fernando;
Revista chilena de neuro-psiquiatría , 2006, DOI: 10.4067/S0717-92272006000300005
Abstract: the frontal lobe, the most human part of the brain (goldberg), has been intensely studied, particularly in the last decades. this region is crucial for the control of behavior, cognition, planning, and working memory. both behavior and higher cognitive abilities depend importantly on the arousal level, and on the autonomic responses that anticipate and accompany behaviors. in this review we will discuss the role played by the medial prefrontal cortex in controlling the level of vigilance and the autonomic and endocrine responses that are crucial for normal behavior. we will also discuss how dysfunctions of the medial prefrontal cortex resulting in the loss of the cortical control over arousal (both behavioral and vegetative) can help to explain the behavioral alterations observed in patients with posttraumatic stress, schizophrenia, attentional deficit and hyperactivity disorder and antisocial and aggressive behavior. additionally we will discuss how studies in rats may give us valuable information about of the mechanisms by which the medial prefrontal cortex is capable of controlling the arousal state, autonomic and emotional responses in humans
Behavioral effects of congenital ventromedial prefrontal cortex malformation
Aaron D Boes, Amanda Grafft, Charuta Joshi, Nathaniel A Chuang, Peg Nopoulos, Steven W Anderson
BMC Neurology , 2011, DOI: 10.1186/1471-2377-11-151
Abstract: B.W.'s behavior has been characterized through extensive review Patience of clinical and personal records along with behavioral and neuropsychological testing. A central feature of the behavioral profile is severe antisocial behavior. He is aggressive, manipulative, and callous; features consistent with psychopathy. Other problems include: egocentricity, impulsivity, hyperactivity, lack of empathy, lack of respect for authority, impaired moral judgment, an inability to plan ahead, and poor frustration tolerance.The vmPFC has a profound contribution to the development of human prosocial behavior. B.W. demonstrates how a congenital lesion to this cortical region severely disrupts this process.The last twenty years have witnessed a surge of discoveries about the ventromedial prefrontal cortex, a brain region centered at the ventral (orbital) and medial surfaces of the prefrontal lobe. Lesion and functional imaging studies have combined to highlight the critical role of the vmPFC in highly valued human processes, including: decision making [1], emotion regulation [2], moral judgment [3], empathy [4], and impulse control [5]. Dysfunction of the vmPFC has been implicated in certain psychiatric disorders, including pathological antisocial behavior (e.g. developmental psychopathy [6], conduct disorder [7], antisocial personality disorder [8]) as well as mood disorders [9] and impulse control disorders (reviewed in [10]).Much of the foundation for what is known about the vmPFC has come from rigorous characterization of the behavioral profile following adult-onset focal lesions of the vmPFC [11-22]. These individuals typically perform normally on a standard neurological exam (language, memory, general intelligence, sensorimotor), but display dramatic disturbances in personality and real world behavior that are more severe than what is seen after injury to other sectors of the prefrontal lobe [23]. Core deficits include: egocentricity, a lack of empathy, poor decision-making,
Refinement of Neuronal Synchronization with Gamma Oscillations in the Medial Prefrontal Cortex after Adolescence  [PDF]
Julián de Almeida, Iván Jourdan, Mario Gustavo Murer, Juan E. Belforte
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0062978
Abstract: The marked anatomical and functional changes taking place in the medial prefrontal cortex (PFC) during adolescence set grounds for the high incidence of neuropsychiatric disorders with adolescent onset. Although circuit refinement through synapse pruning may constitute the anatomical basis for the cognitive differences reported between adolescents and adults, a physiological correlate of circuit refinement at the level of neuronal ensembles has not been demonstrated. We have recorded neuronal activity together with local field potentials in the medial PFC of juvenile and adult mice under anesthesia, which allowed studying local functional connectivity without behavioral or sensorial interference. Entrainment of pyramidal neurons and interneurons to gamma oscillations, but not to theta or beta oscillations, was reduced after adolescence. Interneurons were synchronized to gamma oscillations across a wider area of the PFC than pyramidal neurons, and the span of interneuron synchronization was shorter in adults than juvenile mice. Thus, transition from childhood to adulthood is characterized by reduction of the strength and span of neuronal synchronization specific to gamma oscillations in the mPFC. The more restricted and weak ongoing synchronization in adults may allow a more dynamic rearrangement of neuronal ensembles during behavior and promote parallel processing of information.
Neuroanatomical basis of behavioral disturbances in patients with prefrontal lesions
Biological Research , 2006, DOI: 10.4067/S0716-97602006000200006
Abstract: the role of the frontal lobe in control of behavioral and cognitive abilities is explored in a group of 34 patients with brain lesions restricted to the prefrontal cortex. the scores in both structured behavioral questionnaires and standard neuropsychological tests were analyzed using the injured area of the frontal lobe as the independent variable. our results show that patients with simultaneous lesions in supero_ and inferomedial areas of the prefrontal cortex exhibit higher behavioral disturbances. bilateral lesions also are associated with greater behavioral troubles. on the contrary, cognitive abilities are globally impaired in prefrontal patients. results are discussed in relation to current models of the organization of the prefrontal cortex and its role on behavior control
Neuroanatomical basis of behavioral disturbances in patients with prefrontal lesions
Biological Research , 2006,
Abstract: The role of the frontal lobe in control of behavioral and cognitive abilities is explored in a group of 34 patients with brain lesions restricted to the prefrontal cortex. The scores in both structured behavioral questionnaires and standard neuropsychological tests were analyzed using the injured area of the frontal lobe as the independent variable. Our results show that patients with simultaneous lesions in supero_ and inferomedial areas of the prefrontal cortex exhibit higher behavioral disturbances. Bilateral lesions also are associated with greater behavioral troubles. On the contrary, cognitive abilities are globally impaired in prefrontal patients. Results are discussed in relation to current models of the organization of the prefrontal cortex and its role on behavior control
Diminished Medial Prefrontal Activity behind Autistic Social Judgments of Incongruent Information  [PDF]
Takamitsu Watanabe, Noriaki Yahata, Osamu Abe, Hitoshi Kuwabara, Hideyuki Inoue, Yosuke Takano, Norichika Iwashiro, Tatsunobu Natsubori, Yuta Aoki, Hidemasa Takao, Hiroki Sasaki, Wataru Gonoi, Mizuho Murakami, Masaki Katsura, Akira Kunimatsu, Yuki Kawakubo, Hideo Matsuzaki, Kenji J. Tsuchiya, Nobumasa Kato, Yukiko Kano, Yasushi Miyashita, Kiyoto Kasai, Hidenori Yamasue
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0039561
Abstract: Individuals with autism spectrum disorders (ASD) tend to make inadequate social judgments, particularly when the nonverbal and verbal emotional expressions of other people are incongruent. Although previous behavioral studies have suggested that ASD individuals have difficulty in using nonverbal cues when presented with incongruent verbal-nonverbal information, the neural mechanisms underlying this symptom of ASD remain unclear. In the present functional magnetic resonance imaging study, we compared brain activity in 15 non-medicated adult males with high-functioning ASD to that of 17 age-, parental-background-, socioeconomic-, and intelligence-quotient-matched typically-developed (TD) male participants. Brain activity was measured while each participant made friend or foe judgments of realistic movies in which professional actors spoke with conflicting nonverbal facial expressions and voice prosody. We found that the ASD group made significantly less judgments primarily based on the nonverbal information than the TD group, and they exhibited significantly less brain activity in the right inferior frontal gyrus, bilateral anterior insula, anterior cingulate cortex/ventral medial prefrontal cortex (ACC/vmPFC), and dorsal medial prefrontal cortex (dmPFC) than the TD group. Among these five regions, the ACC/vmPFC and dmPFC were most involved in nonverbal-information-biased judgments in the TD group. Furthermore, the degree of decrease of the brain activity in these two brain regions predicted the severity of autistic communication deficits. The findings indicate that diminished activity in the ACC/vmPFC and dmPFC underlies the impaired abilities of individuals with ASD to use nonverbal content when making judgments regarding other people based on incongruent social information.
Watching cartoons activates the medial prefrontal cortex in children
ShiHui Han,Yi Jiang,Glyn W. Humphreys
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0505-5
Abstract: The medial prefrontal cortex (MPFC) of human adults is involved in attributing mental states to real human agents but not to virtual artificial characters. This study examined whether such differential MPFC activity can be observed in children who are more fascinated by cartoons than adults. We measured brain activity using functional magnetic resonance imaging (fMRI) while 10-year-old children watched movie and cartoon clips, simulating real and virtual visual worlds, respectively. We showed neuroimaging evidence that, in contrast to adults, the MPFC of children was activated when perceiving both human agents and artificial characters in coherent visual events. Our findings suggest that, around the age of 10 years, the MPFC activity in children is different from that in adults in that it can be spontaneously activated by non-human agents in a virtual visual world.
The Role of the Medial Prefrontal Cortex-Amygdala Circuit in Stress Effects on the Extinction of Fear  [PDF]
Irit Akirav,Mouna Maroun
Neural Plasticity , 2007, DOI: 10.1155/2007/30873
Abstract: Stress exposure, depending on its intensity and duration, affects cognition and learning in an adaptive or maladaptive manner. Studies addressing the effects of stress on cognitive processes have mainly focused on conditioned fear, since it is suggested that fear-motivated learning lies at the root of affective and anxiety disorders. Inhibition of fear-motivated response can be accomplished by experimental extinction of the fearful response to the fear-inducing stimulus. Converging evidence indicates that extinction of fear memory requires plasticity in both the medial prefrontal cortex and the amygdala. These brain areas are also deeply involved in mediating the effects of exposure to stress on memory. Moreover, extensive evidence indicates that gamma-aminobutyric acid (GABA) transmission plays a primary role in the modulation of behavioral sequelae resulting from a stressful experience, and may also partially mediate inhibitory learning during extinction. In this review, we present evidence that exposure to a stressful experience may impair fear extinction and the possible involvement of the GABA system. Impairment of fear extinction learning is particularly important as it may predispose some individuals to the development of posttraumatic stress disorder. We further discuss a possible dysfunction in the medial prefrontal cortex-amygdala circuit following a stressful experience that may explain the impaired extinction caused by exposure to a stressor.
Segregation of the human medial prefrontal cortex in social cognition  [PDF]
Danilo Bzdok,Robert Langner,Leonhard Schilbach,Denis A. Engemann,Angela R. Laird,Peter T. Fox,Simon B. Eickhoff
Frontiers in Human Neuroscience , 2013, DOI: 10.3389/fnhum.2013.00232
Abstract: While the human medial prefrontal cortex (mPFC) is widely believed to be a key node of neural networks relevant for socio-emotional processing, its functional subspecialization is still poorly understood. We thus revisited the often assumed differentiation of the mPFC in social cognition along its ventral-dorsal axis. Our neuroinformatic analysis was based on a neuroimaging meta-analysis of perspective-taking that yielded two separate clusters in the ventral and dorsal mPFC, respectively. We determined each seed region's brain-wide interaction pattern by two complementary measures of functional connectivity: co-activation across a wide range of neuroimaging studies archived in the BrainMap database and correlated signal fluctuations during unconstrained (“resting”) cognition. Furthermore, we characterized the functions associated with these two regions using the BrainMap database. Across methods, the ventral mPFC was more strongly connected with the nucleus accumbens, hippocampus, posterior cingulate cortex, and retrosplenial cortex, while the dorsal mPFC was more strongly connected with the inferior frontal gyrus, temporo-parietal junction, and middle temporal gyrus. Further, the ventral mPFC was selectively associated with reward related tasks, while the dorsal mPFC was selectively associated with perspective-taking and episodic memory retrieval. The ventral mPFC is therefore predominantly involved in bottom-up-driven, approach/avoidance-modulating, and evaluation-related processing, whereas the dorsal mPFC is predominantly involved in top–down-driven, probabilistic-scene-informed, and metacognition-related processing in social cognition.
Agency Modulates the Lateral and Medial Prefrontal Cortex Responses in Belief-Based Decision Making  [PDF]
Gui Xue, Qinghua He, Zhong-Lin Lu, Irwin P. Levin, Qi Dong, Antoine Bechara
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0065274
Abstract: Many real-life decisions in complex and changing environments are guided by the decision maker’s beliefs, such as her perceived control over decision outcomes (i.e., agency), leading to phenomena like the “illusion of control”. However, the neural mechanisms underlying the “agency” effect on belief-based decisions are not well understood. Using functional imaging and a card guessing game, we revealed that the agency manipulation (i.e., either asking the subjects (SG) or the computer (CG) to guess the location of the winning card) not only affected the size of subjects’ bets, but also their “world model” regarding the outcome dependency. Functional imaging results revealed that the decision-related activation in the lateral and medial prefrontal cortex (PFC) was significantly modulated by agency and previous outcome. Specifically, these PFC regions showed stronger activation when subjects made decisions after losses than after wins under the CG condition, but the pattern was reversed under the SG condition. Furthermore, subjects with high external attribution of negative events were more affected by agency at the behavioral and neural levels. These results suggest that the prefrontal decision-making system can be modulated by abstract beliefs, and are thus vulnerable to factors such as false agency and attribution.
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