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Psychology & Neuroscience, Volume: 4, Número: 2, Publicado: 2011
  • The First Annual Meeting of the Brazilian Institute of Neuropsychology and Behavior (IBNeC) in conjunction with the Second Forum on the Neurobiology of Stress

    Hazin, Izabe; Bizarro, Lisiane; Almeida, Rosa Maria Martins de
  • Fear, anxiety and their disorders: past, present and future neural theories

    McNaughton, Neil

    Resumo em Inglês:

    This paper reviews the historical development of a two-dimensional (direction x distance (?)) neural model of defense. It begins with Miller's (1944) analysis, and model, of approach, avoidance and conflict; adds Hinde's (1966) ethological perspective and Flynn's (1967) neural model of fear; and then considers Gray's (1967, 1970) work linking barbiturate action to the hippocampus, McNaughton's (1977) extension of this to other classes of anxiolytics, and Gray & McNaughton's (1983) detailed behavioral comparison of anxiolytics and hippocampal lesions. This work led to Gray's (1982) detailed model of the neuropsychology of anxiety. Rapoport's (1989) model of the control of obsession by the cingulate cortex, and Ledoux's (1994) model of the control of both fear and anxiety to the amygdala, suggested a more complex organisation of defense systems. McNaughton (1989) argued that evolutionary function defines an emotion, and Blanchard and Blanchard (1990) argued for its assessment via ethoexperimental analysis. Graeff (1994) then produced a neural model that mapped defensive distance to neural level, treating all anxiety as being at a greater defensive distance than fear. Seeing this, and the treatment of anxiety as due to uncertainty (which is inconsistent with Miller's data), as being unsatisfactory, Gray and McNaughton (2000) and then McNaughton and Corr (2004) developed the two-dimensional model of defensive systems. This model is clearly incomplete at the present time and its links with neuroeconomics, personality, and stress and greater specification of frontal cortical contributions are suggested as directions for future development.
  • Defense-related emotions in humans

    Graeff, Frederico Guilherme

    Resumo em Inglês:

    The study of the role of serotonin in anxiety has led to the view that this neurotransmitter enhances anxiety, but inhibits panic. Validation of this hypothesis has been made using two experimental procedures that increase anxiety in human volunteers. One is classical conditioning of the skin electrical conductance response, which is assumed to represent anxiety. The other is simulated public speaking, which is believed to mobilize the same neural networks that are operative in panic and social anxiety disorders. In general, the results of these studies have fulfilled the predictions derived from the above hypothesis. The same procedures have been applied to panic disorder patients, and the obtained results have shown that these patients had a blunted anxiety response to public speaking. This speaking stress also did not activate the hypothalamic-pituitary-adrenal axis, which, in contrast, was activated by anticipatory anxiety. It may be concluded that anxiety and panic are qualitatively different emotional states, respectively related to the animal defense reactions to potential and proximal threat. In agreement, reported results of recent neuroimaging studies have shown that anxiety activates prefrontal cortical areas, whereas panic activates midbrain regions, particularly the periaqueductal gray matter. As a general conclusion, it may be said that anxiety, fear and panic do not belong to the same continuum of increasing intensity; instead, they are qualitatively different emotional states.
  • The neurobiology of posttraumatic stress disorder: dysfunction in the prefrontal-amygdala circuit?

    Lobo, Isabela; Oliveira, Letícia de; David, Isabel A.; Pereira, Mirtes G.; Volchan, Eliane; Rocha-Rego, Vanessa; Figueira, Ivan; Mocaiber, Izabela

    Resumo em Inglês:

    Posttraumatic stress disorder (PTSD) is an anxiety disorder that can develop following exposure to a traumatic event, including terrifying or life-threatening situations such as sexual assault or natural disasters. The disorder is characterized by a reaction of intense fear, helplessness, or horror when the individual experiences, testifies about, or is faced with one or more events that involve death, severe wounds, or a threat to one's own or another's physical integrity. One of the most important symptoms of PTSD is the revival of the traumatic event, which has been interpreted as an inability to downregulate negative emotions. Neuroimaging studies that probed the ability to regulate emotions in healthy volunteers have found a pattern characterized by activation of the prefrontal cortex associated with a reduction in amygdala activity. This suggests an inhibitory prefrontal cortex-amygdala circuit that underlies emotional regulation. The hypothesis that increased amygdala activation associated with PTSD results from dysfunction in the inhibitory mechanism exerted by the prefrontal cortex has been the topic of debate. The present review investigates the validity of dysfunction in the prefrontal-amygdala pathway in PTSD. The studies provide evidence that the amygdala and prefrontal cortex exhibit distinct activation patterns in PTSD, thus supporting the model of a dysfunctional circuit. Inconsistencies in the literature may be attributable to distinct PTSD subgroups, different experimental approaches, different contrasts employed in neuroimaging studies, and small sample sizes.
  • Panic-like behaviors in Carioca High-and Low-conditioned Freezing rats

    Galvão, Bruno de Oliveira; Gomes, Vitor de Castro; Maisonnette, Silvia; Landeira- Fernandez, J.

    Resumo em Inglês:

    Panic disorder involves both recurrent unexpected panic attacks and persistent concern about having additional attacks. Electrical stimulation of the dorsal periaqueductal gray (dPAG) is an animal model of both panic attack and panic disorder, whereas contextual fear conditioning represents a model of anticipatory anxiety. Previous research indicated that anxiety has an inhibitory effect on panic attack-like behavior. However, still unclear is the role that anticipatory anxiety plays in panic disorder-like behaviors. This issue was investigated with two lines of animals selectively bred for high (Carioca High-Freezing) and low (Carioca Low-Freezing) freezing in response to contextual cues associated with footshock. The results suggest that although anticipatory anxiety might exert an inhibitory effect on the expression of panic attack, it might also facilitate the pathogenesis of panic disorder.
  • Gabaergic mechanisms of anterior and ventromedial hypothalamic nuclei in the expression of freezing in response to a light-conditioned stimulus

    Santos, Julia Maria dos; Brandão, Marcus Lira

    Resumo em Inglês:

    The amygdala, dorsal periaqueductal gray (dPAG), and medial hypothalamus have long been recognized to comprise a neural system responsible for the generation and elaboration of unconditioned fear in the brain. This neural substrate is well known to be under tonic inhibitory control exerted by γ-aminobutyric acid (GABA) mechanisms. Some evidence also suggests that these structures integrate conditioned fear. A recent study using the fear-potentiated startle paradigm showed that GABAergic mechanisms in the anterior hypothalamic nucleus (AHN) and dorsomedial part of the ventromedial hypothalamic nucleus (VMHDM) regulate conditioned fear. The present study examined the extent to which GABAergic mechanisms in these brain regions are involved in conditioned fear by measuring freezing in response to a light used as a conditioned stimulus (CS). The GABA A receptor agonist muscimol and the GABA-synthesizing enzyme glutamic acid decarboxylase inhibitor semicarbazide were used as an enhancer and inhibitor of GABA mechanisms, respectively. Muscimol and semicarbazide were injected into the AHN or VMHDM of rats before fear conditioning. Muscimol injections into the AHN and VMHDM significantly reduced conditioned freezing, whereas inhibition of GABA transmission increased this conditioned response in the AHN. The present study further supports the hypothesis that GABAergic mechanisms in the AHN and VMHDM exert inhibitory control on the neural substrates of conditioned fear in the hypothalamus.
  • Analysis of the occurrence of early life stress in adult psychiatric patients: a systematic review

    Martins, Camila Maria Severi; Tofoli, andra Marcia de Carvalho; Baes, Cristiane Von Werne; Juruena, Mario

    Resumo em Inglês:

    The purpose of the paper was to conduct a systematic review of early life stress and its association with psychiatric disorders in adulthood. The occurrence of early stress has lasting negative consequences on the individual, with psychopathology onset one of the most important consequences. The degree of early life stress is associated with the severity of psychiatric disorders and disability in adulthood. Methodology: We conducted a search of two databases (PubMed and SciELO), limited to the time span 1990-2010, using the following keywords: child abuse, maltreatment, early stress, and psychiatric disorders. Thirty-one papers were selected for this review. Results: We found that the subtypes of early life stress such as emotional and physical neglect and sexual, emotional, and physical abuse have associations with several psychiatric disorders, but the Borderline Personality Disorder and Mood Disorders are more associated with the categories listed. Conclusions: Exposure to adversities in childhood and adolescence is predictive of psychiatric disorders in adulthood. More studies are needed to understand the mechanisms by which early life stress is a risk factor for future psychopathology.
  • Early life stress, HPA axis, and depression

    Tofoli, Sandra Marcia de Carvalho; Baes, Cristiane Von Werne; Martins, Camila Maria Severi; Juruena, Mario

    Resumo em Inglês:

    Considerable evidence from various studies suggests a preeminent role for early adverse experiences in the development of psychopathology, especially depression. The most recent studies reviewed herein suggest that early life stressors are associated with an increased risk for mood disorders in adulthood. This review examines the emerging literature on the relationship between stress, hypothalamic-pituitary-adrenal (HPA) axis function, and depression and the role of early life stress as an important risk factor for HPA axis dysregulation. The most consistent findings in the literature show increased activity of the HPA axis in depression associated with hypercortisolemia and reduced inhibitory feedback. Moreover, HPA axis changes appear to be state-dependent, tending to improve upon resolution of the depressive syndrome. Interestingly, persistent HPA hyperactivity has been associated with higher rates of relapse. These studies suggest that an evaluation of the HPA axis during antidepressant treatment may help identify patients who are at a higher risk for relapse. These findings suggest that this dysregulation of the HPA axis is partially attributable to an imbalance between glucocorticoid and mineralocorticoid receptors. Evidence has consistently demonstrated that glucocorticoid receptor function is impaired in major depression, but few studies have assessed the activity of mineralocorticoid receptors in depression. Thus, more studies are needed to elucidate this issue.
  • Proprioceptive deficits in Parkinson's disease: from clinical data to animal experimentation

    Ribeiro, Letícia; Souza, Tadeu Mello e; Bizarro, Lisiane; Oliveira, Alcyr

    Resumo em Inglês:

    Parkinson's disease (PD) is characterized by the manifestation of akinesia, slowness to initiate movement, muscle rigidity, and tremors. However, recent evidence indicates that this pathology also causes alterations in proprioception. Disturbances in proprioceptive mechanisms directly affect postural control and the ability to calculate the velocity and amplitude of movement, suggesting that these alterations are related to the motor symptoms of PD. This article reviews the clinical data on these symptoms and presents evidence of a connection between proprioceptive deficits and the physiology of PD. The identification of proprioceptive impairments in different forms of Parkinsonism can provide valuable clues on the physiopathology of proprioception in idiopathic PD.
  • Neuropsychological and neurobiological markers of the preclinical stage of Alzheimer's disease

    Fichman, Helenice Charchat; Oliveira, Rosinda Martins; Fernandes, Conceição Santos

    Resumo em Inglês:

    Dementia, especially Alzheimer's disease, has a high prevalence in the elderly population. Therefore, identifying individuals who are at a high risk for early diagnosis is crucial to allow both pharmacological and behavioral therapeutic interventions, which in some cases can delay the progression of dementia. This paper describes neuropsychological and neurobiological markers for the early diagnosis of Alzheimer's disease and presents the main risk factors, including neuropathological, neuroanatomical, neurofunctional, genetic, and neuropsychological. The literature shows that the combination of these markers is the best method for predicting Alzheimer's disease, years before its clinical manifestation. The most prevalent neurobiological and neuropsychological risk factors include (1) senile plaques and neurofibrillary tangles in the medial temporal lobe and cortical regions, (2) low concentrations of Aβ1-42 peptide and high concentrations of total tau protein and phosphorylated tau protein in cerebrospinal fluid, (3) reduced global cerebral volume, increased ventricular volume, and atrophy in the hippocampal formation and entorhinal cortex, (4) global reductions in cerebral metabolism and perfusion in the temporoparietal junction, temporal, parietal, and frontal lobes, hippocampal formation, and posterior cingulate cortex, (5) the presence of the apolipoprotein E ε4 allele, and (6) verbal anterograde episodic long-term memory impairment and executive dysfunction. The present review discusses the evidence for markers that identify individuals who are at a high risk of developing Alzheimer's disease and the importance of longitudinal studies in this context.
  • The use of the Cambridge Neuropsychological Test Automated Battery (CANTAB) in neuropsychological assessment: application in Brazilian research with control children and adults with neurological disorders

    Roque, Daniela Tsubota; Teixeira, Rosani Aparecida Antunes; Zachi, Elaine C.; Ventura, Dora F.

    Resumo em Inglês:

    Computerized neuropsychological tests can be effective and have many benefits. This paper addresses these issues using the computer-based Cambridge Neuropsychological Test Automated Battery (CANTAB) to assess Brazilian children and adults. Preliminary normative data for Brazilian children obtained in a series of CANTAB subtests are presented together with data from adults (controls) and samples of patients with multiple sclerosis and Duchenne muscular dystrophy. The results obtained in children confirmed the normative values reported for American children (Luciana & Nelson, 2002), indicating high applicability of the CANTAB battery for children in the evaluation of visual memory, working memory, planning, and set shifting. For multiple sclerosis patients, CANTAB revealed differences between the control and multiple sclerosis groups for all subtests employed, including visual memory, working memory, spatial memory, decision making, inhibitory control, and sustained attention. In children with Duchenne muscular dystrophy, the CANTAB tests revealed specific detriments in attention and memory. These results of the application of CANTAB in different patient groups indicate that the battery is appropriate for assessing several central nervous system diseases.
  • Frontal stroke: problem solving, decision making, impulsiveness, and depressive symptoms in men and women

    Scheffer, Morgana; Monteiro, Janine Kieling; Almeida, Rosa Maria Martins de

    Resumo em Inglês:

    The present study compared men and women who suffered a frontal lobe stroke with regard to problem solving, decision making, impulsive behavior and depressive symptoms and also correlated these variables between groups. The sample was composed of 10 males and nine females. The study period was 6 months after the stroke. The following instruments were used: Wisconsin Card Sort Test (WCST), Iowa Gambling Task (IGT), Barrat Impulsiveness Scale (BIS11), and Beck Depression Inventory (BDI). For the exclusion criteria of the sample, the Mini International Psychiatric Interview (M.I.N.I Plus) and Mini Mental Stage Examination (MMSE) were used. To measure functional severity post-stroke, the Rankin Scale was used. The average age was 60.90 ± 8.93 years for males and 60.44 ± 11.57 years for females. In females, total impulsiveness (p = .013) and lack of planning caused by impulsiveness (p = .028) were significantly higher compared with males, assessed by the BIS11. These data indicate that females in the present sample who suffered a chronic frontal lesion were more impulsive and presented more planning difficulties in situations without demanding cognitive processing. These results that show gender differences should be considered when planning psychotherapy and cognitive rehabilitation for patients who present these characteristics.
  • Dynamics of a Stroop matching task: effect of alcohol and reversal with training

    David, Isabel A.; Volchan, Eliane; Alfradique, Isabel; Oliveira, Letícia de; Pereira, Mirtes G.; Ranvaud, Ronald; Vila, Jaime; Machado-Pinheiro, Walter

    Resumo em Inglês:

    Using a Stroop matching task, we evaluated how alcohol affects the time needed to overcome Stroop conflict and whether practice might reverse the effect of alcohol. Participants (n = 16) performed two sessions in which they had to compare the color of a color-word with the meaning of a color-word in neutral color. The two task stimuli were presented simultaneously or with a Stimulus Onset Asynchrony (SOA) of 200, 500, or 800 ms. For half of the subjects, alcohol was administered in the first session, and for the other half, alcohol was administered in the second session. The results showed that the Stroop effect was significant at the 0 and 200 ms intervals in the sober subjects. Moreover, in untrained intoxicated individuals, interference endured until the 500 ms interval, a result that was abolished in trained intoxicated subjects. In conclusion, alcohol increased the time needed for Stroop matching task conflict resolution. However, this deleterious effect was minimized by a previous practice session.
  • Pervasive development disorder explained by the theory of executive dysfunction: case study

    Fontanari, Anna Martha Vaitses; Vaitses, Vivian Denise Cazerta

    Resumo em Inglês:

    A case of a hyperactive child with impaired speech, perceptual-motor capacity and interpersonal skills is presented. Presumptive diagnoses are discussed according to the international classifications most often used. The nature of pervasive developmental disorders is examined based on the concepts of theory of mind and theory of executive dysfunction.
  • On selecting emotional outcomes in a rehabilitation program for persons with traumatic brain injury in Brazil

    Pereira, Ana Paula Almeida de

    Resumo em Inglês:

    Traumatic brain injury (TBI) is an important health problem in Brazil. It frequently results in a variety of sequelae, including cognitive, behavioral, and physical impairments that are frequently related to difficulties in community reintegration and successful rehabilitation outcomes. The literature shows that several variables are involved in positive outcomes, including neuropsychological deficits, services received, and social support. Brazil has a paucity of rehabilitation programs for persons with TBI. Intervention outcomes are underreported, and culturally adapted rehabilitation strategies are rarely found. The present study describes a rehabilitation program, presents emotional factors as an important outcome, and discusses a case that illustrates the major points debated.
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