1980 Preface * 1999 Preface * 1999 Acknowledgements * Introduction * 1 Circular Logic * 2 Phase Singularities (Screwy Results of Circular Logic) * 3 The Rules of the Ring * 4 Ring Populations * 5 Getting Off the Ring * 6 Attracting Cycles and Isochrons * 7 Measuring the Trajectories of a Circadian Clock * 8 Populations of Attractor Cycle Oscillators * 9 Excitable Kinetics and Excitable Media * 10 The Varieties of Phaseless Experience: In Which the Geometrical Orderliness of Rhythmic Organization Breaks Down in Diverse Ways * 11 The Firefly Machine 12 Energy Metabolism in Cells * 13 The Malonic Acid Reagent ('Sodium Geometrate') * 14 Electrical Rhythmicity and Excitability in Cell Membranes * 15 The Aggregation of Slime Mold Amoebae * 16 Numerical Organizing Centers * 17 Electrical Singular Filaments in the Heart Wall * 18 Pattern Formation in the Fungi * 19 Circadian Rhythms in General * 20 The Circadian Clocks of Insect Eclosion * 21 The Flower of Kalanchoe * 22 The Cell Mitotic Cycle * 23 The Female Cycle * References * Index of Names * Index of Subjects

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/596B270197FE27DE5FABB598B6210622/S0025557200150892a.pdf/div-class-title-span-class-italic-the-geometry-of-biological-time-span-by-a-t-winfree-pp-544-dm68-corrected-second-printing-1990-isbn-3-540-52528-9-springer-div.pdf

The geometry of biological time , by A. T. Winfree. Pp 544. DM68. Corrected Second Printing 1990. ISBN 3-540-52528-9 (Springer)

The brain is the key organ of the response to stress because it determines what is threatening and, therefore, potentially stressful, as well as the physiological and behavioral responses which can be either adaptive or damaging. Stress involves two-way communication between the brain and the cardiovascular, immune, and other systems via neural and endocrine mechanisms. Beyond the "flight-or-fight" response to acute stress, there are events in daily life that produce a type of chronic stress and lead over time to wear and tear on the body ("allostatic load"). Yet, hormones associated with stress protect the body in the short-run and promote adaptation ("allostasis"). The brain is a target of stress, and the hippocampus was the first brain region, besides the hypothalamus, to be recognized as a target of glucocorticoids. Stress and stress hormones produce both adaptive and maladaptive effects on this brain region throughout the life course. Early life events influence life-long patterns of emotionality and stress responsiveness and alter the rate of brain and body aging. The hippocampus, amygdala, and prefrontal cortex undergo stress-induced structural remodeling, which alters behavioral and physiological responses. As an adjunct to pharmaceutical therapy, social and behavioral interventions such as regular physical activity and social support reduce the chronic stress burden and benefit brain and body health and resilience.

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Physiology and Neurobiology of Stress and Adaptation: Central Role of the Brain

http://findlab.stanford.edu/Publications/Biol%20Psych_in%20press.pdf

Resting-State Functional Connectivity in Major Depression: Abnormally Increased Contributions from Subgenual Cingulate Cortex and Thalamus

The neural networks that putatively modulate aspects of normal emotional behavior have been implicated in the pathophysiology of mood disorders by converging evidence from neuroimaging, neuropathological and lesion analysis studies. These networks involve the medial prefrontal cortex (MPFC) and closely related areas in the medial and caudolateral orbital cortex (medial prefrontal network), amygdala, hippocampus, and ventromedial parts of the basal ganglia, where alterations in grey matter volume and neurophysiological activity are found in cases with recurrent depressive episodes. Such findings hold major implications for models of the neurocircuits that underlie depression. In particular evidence from lesion analysis studies suggests that the MPFC and related limbic and striato-pallido-thalamic structures organize emotional expression. The MPFC is part of a larger “default system” of cortical areas that include the dorsal PFC, mid- and posterior cingulate cortex, anterior temporal cortex, and entorhinal and parahippocampal cortex, which has been implicated in self-referential functions. Dysfunction within and between structures in this circuit may induce disturbances in emotional behavior and other cognitive aspects of depressive syndromes in humans. Further, because the MPFC and related limbic structures provide forebrain modulation over visceral control structures in the hypothalamus and brainstem, their dysfunction can account for the disturbances in autonomic regulation and neuroendocrine responses that are associated with mood disorders. This paper discusses these systems together with the neurochemical systems that impinge on them and form the basis for most pharmacological therapies.

/pdf/brain-structural-and-functional-abnormalities-in-mood-4313buqwur.pdf

Brain structural and functional abnormalities in mood disorders: implications for neurocircuitry models of depression

Depression is related to the normal emotions of sadness and bereavement, but it does not remit when the external cause of these emotions dissipates, and it is disproportionate to their cause. Classic severe states of depression often have no external precipitating cause. It is difficult, however, to draw clear distinctions between depressions with and those without psychosocial precipitating events. 1 The diagnosis of major depressive disorder requires a distinct change of mood, characterized by sadness or irritability and accompanied by at least several psychophysiological changes, such as disturbances in sleep, appetite, or sexual desire; constipation; loss of the ability to experience pleasure in work or with friends; crying; suicidal thoughts; and slowing of speech and action. These changes must last a minimum of 2 weeks and interfere considerably with work and family relations. On the basis of this broad definition, the lifetime incidence of depression in the United States is more than 12% in men and 20% in women. 2 Some have advocated a much narrower definition of severe depression, which they call melancholia or vital depression. 3 A small percentage of patients with major depression have had or will have manic episodes consisting of hyperactivity, euphoria, and an increase in pleasure seeking. Although some pathogenetic mechanisms in these cases and in cases of major depressive disorder overlap, a history of mania defines a distinct illness termed bipolar disorder. 4 Depression is a heterogeneous disorder with a highly variable course, an inconsistent response to treatment, and no established mechanism. This review presents the major current approaches to understanding the biologic mechanisms of major depression.

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Major depressive disorder.

Studies have examined hippocampal function and volume in depressed subjects, but none have systematically compared never-treated first-episode patients with those who have had multiple episodes. We sought to compare hippocampal function, as assessed by performance on hippocampal-dependent recollection memory tests, and hippocampal volumes, as measured in a 1.5-T magnetic resonance imager, in depressed subjects experiencing a postpubertal onset of depression. Twenty never-treated depressed subjects in a first episode of depression were compared with matched healthy control subjects. Seventeen depressed subjects with multiple past episodes of depression were also compared with matched healthy controls and to the first-episode patients. Both first- and multiple-episode depressed groups had hippocampal dysfunction apparent on several tests of recollection memory; only depressed subjects with multiple depressive episodes had hippocampal volume reductions. Curve-fitting analysis revealed a significant logarithmic association between illness duration and hippocampal volume. Reductions in hippocampal volume may not antedate illness onset, but volume may decrease at the greatest rate in the early years after illness onset.

https://www.pnas.org/content/pnas/100/3/1387.full.pdf

Course of illness, hippocampal function, and hippocampal volume in major depression

Objective: The aim of this paper is to review outcome in patients with bipolar disorder as assessed by interepisode level of functioning, as until recently this dimension of outcome has been relatively under-emphasized.



Method: Studies that examined psychosocial outcome in bipolar disorder were reviewed on the basis of rating measurements employed, length of follow-up, number of subjects followed and degree of impairment reported. Studies were included only if results from patients with bipolar and unipolar disorder were reported in such a way that the groups could be distinguished.



Results: When studies of psychosocial outcome in bipolar disorder are examined in aggregate, it appears that 30–60% of individuals with this disorder fail to regain full functioning in occupational and social domains.



Conclusion: This review highlights the fact that inter-episode functional recovery is incomplete in some patients, suggesting that comprehensive rehabilitative assessment and intervention may be essential to reduce the morbidity associated with this disorder.

A review of psychosocial outcome in patients with bipolar disorder.

Studies have examined hippocampal function and volume in depressed subjects, but none have systematically compared never-treated first-episode patients with those who have had multiple episodes. We sought to compare hippocampal function, as assessed by performance on hippocampal-dependent recollection memory tests, and hippocampal volumes, as measured in a 1.5-T magnetic resonance imager, in depressed subjects experiencing a postpubertal onset of depression. Twenty never-treated depressed subjects in a first episode of depression were compared with matched healthy control subjects. Seventeen depressed subjects with multiple past episodes of depression were also compared with matched healthy controls and to the first-episode patients. Both first- and multiple-episode depressed groups had hippocampal dysfunction apparent on several tests of recollection memory; only depressed subjects with multiple depressive episodes had hippocampal volume reductions. Curve-fitting analysis revealed a significant logarithm...

/pdf/course-of-illness-hippocampal-function-and-hippocampal-30a0r1wbjw.pdf

Course of Illness, Hippocampal Function, and Hippocampal Volume in Major Depression

Objective: This study’s purpose was to clarify the appropriate treatment of bipolar depression by comparing the addition of an antidepressant versus a second mood stabilizer for inpatients being treated with lithium carbonate or divalproex sodium. Method: Twentyseven patients were randomly assigned to groups that received double-blind treatment with paroxetine or a second mood stabilizer (lithium carbonate or divalproex sodium) for 6 weeks. Results: Both groups showed significant improvement in depressive symptoms during the 6-week trial. There were significantly more noncompleters in the group being treated with the two mood stabilizers than in the group being treated with a mood stabilizer and paroxetine. Conclusions: Both treatments appeared to be effective; however, the addition of an antidepressant may have greater clinical utility in the treatment of bipolar depression. (Am J Psychiatry 2000; 157:124‐126)

https://ajp.psychiatryonline.org/doi/pdf/10.1176/ajp.157.1.124

Double-blind comparison of addition of a second mood stabilizer versus an antidepressant to an initial mood stabilizer for treatment of patients with bipolar depression.

Background: Many patients with bipolar disorder (BD) do not regain full function following an acute illness episode, but the extent to which this impairment is the result of persistent symptoms has not been well established. This study examined factors associated with persistent subsyndromal symptoms in a well characterized group of BD patients who were prospectively followed for an average of 3 years.



Methods: Detailed life charting data from 138 patients with BD were reviewed. Patients were categorized into euthymic, subsyndromal or syndromal groups according to the clinical state during their most recent year of follow-up. The three groups were then examined with respect to comorbidity, function and treatment received.



Results: Patients with subsyndromal symptoms had high rates of comorbid anxiety disorders, and were more likely to have increased rates of eating disorders as well. Patients with subsyndromal symptoms had lower global assessment of function (GAF) scores than euthymic patients, and had as many clinic contacts and medication trials as patients with full episodes of illness.



Conclusions: Persistent subsyndromal symptoms in BD patients are associated with high rates of comorbidity that is important to recognize and treat in order to optimize mood and functioning.

Russell T. Joffe

Papers

Course of illness, hippocampal function, and hippocampal volume in major depression

A review of psychosocial outcome in patients with bipolar disorder.

Course of Illness, Hippocampal Function, and Hippocampal Volume in Major Depression

Double-blind comparison of addition of a second mood stabilizer versus an antidepressant to an initial mood stabilizer for treatment of patients with bipolar depression.

Subsyndromal symptoms assessed in longitudinal, prospective follow-up of a cohort of patients with bipolar disorder.