Jeannette L. Johnson

Bio: Jeannette L. Johnson is an academic researcher from University at Buffalo. The author has contributed to research in topics: Substance abuse prevention & Substance abuse. The author has an hindex of 19, co-authored 42 publications receiving 2410 citations. Previous affiliations of Jeannette L. Johnson include National Institutes of Health.

Cerebral glucography with positron tomography. Use in normal subjects and in patients with schizophrenia.

Abstract: • Local cerebral uptake of deoxyglucose labeled with fluorine 18 was measured by positron-emission tomography in eight patients with schizophrenia who were not receiving medication and in six age-matched normal volunteers. Subjects sat in an acoustically treated, darkened room with eyes closed after injection of 3 to 5 mCi of deoxyglucose18F. After uptake, seven to eight horizontal brain scans parallel to the canthomeatal line were done. Scans were treated digitally, with a 2.3-cm strip peeled off each slice and ratios to whole-slice activity computed. Patients with schizophrenia showed lower ratios in the frontal cortex, indicating relatively lower glucose use than normal control subjects; this was consistent with previously reported studies of regional cerebral blood flow. Patients also showed diminished ratios for a 2.3-cm square that was positioned over central gray-matter areas on the left but not on the right side. These findings are preliminary; issues of control of mental activity, brain structure identification, and biologic and anatomic heterogeneity of schizophrenia remain to be explored.

Anteroposterior gradients in cerebral glucose use in schizophrenia and affective disorders.

Abstract: • Local cerebral uptake of deoxyglucose labeled with fluorine 18 was measured by positron emission tomography in 16 patients with schizophrenia and 11 patients with affective disorder. Patients received no medication a minimum of 14 days and an average of 39.8 days. The subjects were administered the deoxyglucose 18F just before receiving a 34-minute 1/s series of unpleasant electrical stimuli to the right forearm while resting with eyes closed in a darkened, acoustically attenuated psychophysiologic testing chamber. Following monitored stimulation in the controlled environment, subjects were scanned and images converted to values of glucose use in micromoles per 100 g per minute according to Sokoloff's model. Data were analyzed with a four-way analysis of variance (ANOVA) with independent groups (normals, schizophrenics, and affectives) and repeated measures for slice level (supraventricular, midventricular, and infraventricular), hemisphere (right, left), and anteroposterior position (four sectors). Both normal subjects and patients showed a significant anteroposterior gradient in glucose use with highest values in the frontmost sector. Patients both with schizophrenia and with affective illness showed less of an anteroposterior gradient especially at superior levels, which was statistically confirmed by ANOVA. Absolute glucose levels in patients, which were actually higher in posterior regions rather than lower in frontal regions, were the largest contributors to the effect. Neither group differences in whole brain glucose use nor left-right asymmetries reached statistical significance. These results are consistent with our earlier reports of a relative hypofrontal function in schizophrenia compared with controls. This report extends this finding to affective illness, sharing a lack of diagnostic specificity with many biologic measures.

Introduction to the Special Issue on Resilience

Abstract: This article introduces this special issue on resilience by briefly reviewing its history and how contemporary researchers and theorists deliberate it today. Resilience, as a concept, emerged primarily from the work of Norman Garmezy, Emmy Werner, and Ruth Smith. It has transformed the field and shifted research, theory, and practice paradigms to a focus on strengths rather than deficits.

The Construct of Resilience: A Critical Evaluation and Guidelines for Future Work

Abstract: This paper presents a critical appraisal of resilience, a construct connoting the maintenance of positive adaptation by individuals despite experiences of significant adversity. As empirical research on resilience has burgeoned in recent years, criticisms have been levied at work in this area. These critiques have generally focused on ambiguities in definitions and central terminology; heterogeneity in risks experienced and competence achieved by individuals viewed as resilient; instability of the phenomenon of resilience; and concerns regarding the usefulness of resilience as a theoretical construct. We address each identified criticism in turn, proposing solutions for those we view as legitimate and clarifying misunderstandings surrounding those we believe to be less valid. We conclude that work on resilience possesses substantial potential for augmenting the understanding of processes affecting at-risk individuals. Realization of the potential embodied by this construct, however, will remain constrained without continued scientific attention to some of the serious conceptual and methodological pitfalls that have been noted by skeptics and proponents alike.

The prefrontal cortex

Abstract: The Prefrontal Cortex, Fifth Edition, provides users with a thoroughly updated version of this comprehensive work that has historically served as the classic reference on this part of the brain. The book offers a unifying, interdisciplinary perspective that is lacking in other volumes written about the frontal lobes, and is, once again, written by the award-winning author who discovered "memory cells," the physiological substrate of working memory. The fifth edition constitutes a comprehensive update, including all the major advances made on the physiology and cognitive neuroscience of the region since publication in 2008. All chapters have been fully revised, and the overview of prefrontal functions now interprets experimental data within the theoretical framework of the new paradigm of cortical structure and dynamics (the Cognit Paradigm), addressing the accompanying social, economic, and cultural implications. * Provides a distinctly interdisciplinary view of the prefrontal cortex, covering all major methodologies, from comparative anatomy to modern imaging* Unique analysis and synthesis of a large body of basic and clinical data on the subject (more than 2000 references)* Written by an award-winning author who discovered "memory cells," the physiological substrate of working memory* Synthesizes evidence that the prefrontal cortex constitutes a complex pre-adaptive system* Incorporates emerging study of the role of the frontal lobes in social, economic, and cultural adaptation

Subgenual prefrontal cortex abnormalities in mood disorders

Abstract: Pathological disturbances of mood may follow a 'bipolar' course, in which normal moods alternate with both depression and mania, or a 'unipolar' course, in which only depression occurs. Both bipolar and unipolar disorders can be heritable illnesses associated with neurochemical, neuroendocrine and autonomic abnormalities. The neurobiological basis for these abnormalities has not been established. Using positron emission tomographic (PET) images of cerebral blood flow and rate of glucose metabolism to measure brain activity, we have now localized an area of abnormally decreased activity in the prefrontal cortex ventral to the genu of the corpus callosum in both familial bipolar depressives and familial unipolar depressives. This decrement in activity was at least partly explained by a corresponding reduction in cortical volume, as magnetic resonance imaging (MRI) demonstrated reductions in the mean grey matter volume in the same area of 39 and 48% in the bipolar and unipolar samples, respectively. This region has previously been implicated in the mediation of emotional and autonomic responses to socially significant or provocative stimuli, and in the modulation of the neurotransmitter systems targeted by antidepressant drugs.

Physiologic dysfunction of dorsolateral prefrontal cortex in schizophrenia. I. Regional cerebral blood flow evidence.

Abstract: • To evaluate dorsolateral prefrontal cortex (DLPFC) physiology and function simultaneously, 20 medication-free patients with chronic schizophrenia and 25 normal controls underwent three separate xenon Xe 133 inhalation procedures for determination of regional cerebral blood flow (rCBF): first at rest, then while performing an automated version of the Wisconsin Card Sort (WCS), a DLPFC-specific cognitive test, and while peforming a simple number-matching (NM) test. During rest, patients had significantly reduced relative, but not absolute, rCBF to DLPFC. During NM, no specific region differentiated patients from controls. During WCS, however, both absolute and relative rCBF to DLPFC significantly distinguished patients from controls. While controls showed a clear increase in DLPFC rCBF, patients did not. The changes were regionally specific, involving only DLPFC. Furthermore, in patients, DLPFC rCBF correlated positively with WCS cognitive performance, suggesting that the better DLPFC was able to function, the better patients could perform. Autonomic arousal measures, the pattern of WCS errors, and results of complementary studies suggest that the DLPFC finding is linked to regionally specific cognitive function and is not a nonspecific epiphenomenon.

Circuitry of Primate Prefrontal Cortex and Regulation of Behavior by Representational Memory

Abstract: The sections in this article are: 1 Essence of Prefrontal Function: Regulation of Behavior by Representational Knowledge 11 Subdivisions of Prefrontal Cortex 12 Global Nature of Prefrontal Syndrome in Humans 13 Animal Model for Prefrontal Function in Humans 14 Delayed-Response Tests and Varying Interpretations of Their Functional Significance 15 Distractability and Perseveration: Secondary Consequences of Basic Defect in Representational Memory 16 Representational Memory in Wisconsin Card Sort and Other Diagnostic Tests of Prefrontal Function in Humans 17 Localization of Delayed-Response Function: Principal Sulcus 18 Circuit Basis of Visuospatial Functions 2 Accessing and “On-Line” Processing of Representations in Visuospatial Domain: Parietal-Prefrontal Connections 21 Visuospatial Representational Memory in Humans 22 Spatial-Mnemonic Nature of Delayed-Response Deficit: Domain-Specific Memory Loss 23 Topography of Representational Memory in Prefrontal Cortex 24 Electrophysiological Evidence of Spatial-Mnemonic Processes in Principal Sulcus 25 Parietal-Prefrontal Connectivity 26 Columnar and Laminar Framework for Feedforward and Feedback Mechanisms 27 Functional Significance of Parietal-Prefrontal Collaboration 3 Long-Term Memory and “Off-Line” Processing: Prefrontal-Limbic Connections 31 Role of Hippocampus in Spatial Memory 32 Multiple Connections Between Principal Sulcus and Hippocampal Formation 33 Quadripartite Neural Network: Parietal-Temporal-Cingulate-Prefrontal Circuit 34 Limbic Contribution to Spatial Memory 4 Response Initiation and Inhibition: Projections to Striatum, Tectum, Thalamus, and Premotor Cortex 41 Motor-Control Functions of Prefrontal Cortex 42 Cortical-Striatal Pathway and Related Feedback Loops 43 Cortical-Tectal Pathway 44 Thalamic-Cortical Systems 45 Prefrontal-Premotor Connections: Anterior Supplementary Motor Cortex Relays 46 Functional Speculations 5 Modulatory Mechanisms: Brain Stem Catecholamine Projections 51 Activation of Cognitive Machinery 52 Concentration and Synthesis of Catecholamines in Primate Cortex 53 Brain Stem Innervation of Prefrontal Cortex 54 Delayed-Response Deficits and Recovery Produced by Catecholamine Loss and Replacement in Prefrontal Cortex 55 Circuit Basis for Neuromodulation in Principal Sulcus 6 Multiple Subsystems of Prefrontal Cortex: Unity or Diversity of Function 61 Unity or Diversity of Prefrontal Function 62 Frontal Eye Fields 63 Inferior Convexity 64 Orbital Prefrontal Cortices 65 Problem of Integration 7 Diseases Affecting Prefrontal Cortex 71 Schizophrenia: Loss of Corticocortical Processing and Regulation of Behavior by Representational Knowledge 72 Wernicke-Korsakoff Syndrome: Loss of Thalamocortical and Brain Stem Modulatory Mechanisms 73 Huntington's Chorea and Parkinson's Disease: Loss of Prefrontal-Striatal Mechanisms and Initiation or Inhibition of Motor Response 74 Overview of Neurobiology of Disease 8 Summary