Selected examples from man and canine experiments with time series of reticular neurons, respiration, arterial blood pressure, and cutaneous forehead blood content fluctuations were analyzed using multiscaled Time-Frequency-Distribution (TFD), Post-Event-Scan (PES), and Pointwise Transinformation (PTI), resp.. We found in both experiments a "0.15 Hz rhythm" which exhibited periods of spindle wave epochs (increasing and decreasing amplitudes) to be phase synchronized with respiration at 1:2, 1:1 and 2:1 integer number ratios. At times of these wave-epochs and n:m phase-synchronization, the "0.15 Hz rhythm" appeared also in heart rate and arterial blood pressure fluctuations. If phase synchronization of the "0.15 Hz rhythm" with respiration was established at a 1:1 integer number ratio, it was maintained throughout and resulted in consensualization of all cardio-vascular-respiratory oscillations at 0.15 Hz. Analysis of a canine experiment supplied evidence that the emergence of the "0.15Hz rhythm" and n:m phase synchronization appears to result from a decline in the level of the general activity of the organism which was associated with a decline in the level of activity of reticular neurons in the lower brainstem network. These findings corroborate the notion of the "0.15 Hz rhythm" to be a state marker of the `trophotropic mode of operation` which was introduced by W.R. Hess.

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Neurofunctional alterations in acute posttraumatic stress disorder (PTSD) and changes thereof during the course of the disease are not well investigated. We used functional magnetic resonance imaging to assess the functional neuroanatomy of emotional memory in surgical patients with acute PTSD. Traumatic (relative to non-traumatic) memories increased neural activity in the amygdala, hippocampus, lateral temporal, retrosplenial, and anterior cingulate cortices. These regions are all implicated in memory and emotion. A comparison of findings with data on chronic PTSD suggests that brain circuits affected by the acute disorder are extended and unstable while chronic disease is characterized by circumscribed and stable neurofunctional abnormalities.

The autonomic nervous system (ANS) receives modulatory input from high-level supra-tentorial brain structures, which affects peripheral physiological measures such as heart rate variability (HRV), respiration, and electrodermal activity (see Beissner, Meissner, Bär, & Napadow, 2013 for a meta-analysis). For instance, in the neurovisceral integration model for HRV (Thayer & Lane, 2009), neocortical areas such as the prefrontal and cingulate cortex exert tonic inhibitory control over brainstem circuitry underlying the ANS regulation. A similar cortico-limbic model has been proposed for sensorimotor integration of respiration (Evans, 2010), with an interplay of volitional respiratory control (pre-motor and supplementary motor area (SMA)) and interoceptive integration areas (anterior cingulate cortex (ACC), insula, and amygdala). These models overlap in core autonomic network areas, including the cingulate cortex, insula, and amygdala

BackgroundBariatric surgery has gained increasing relevance due to the dramatic rise in morbid obesity prevalence. A sound body of scientific literature demonstrates positive long-term outcome of bariatric surgery in decreasing mental and physical health morbidity. Still, there is a need for a manageable presurgical screening to assess major mental disorders. The aim of this study was to assess the frequency of common psychiatric syndromes in bariatric surgery candidates using a computerized version of the Patient Health Questionnaire (PHQ).MethodsIn a prospective cohort study from August 2009 to July 2011 morbidly obese individuals seeking bariatric treatment were evaluated for mental health disorders using the PHQ (computerized German version).ResultsA total of 159 patients were included in this study. The median age of participants was 42 years, the median BMI was 49 kg/m2. The PHQ revealed a prevalence of 84 % for mental health disorders, 50 % of the participants had three or more mental health disorders. A high somatic symptom burden (46 %), depressive syndromes (62 %) and anxiety disorders (29 %) were the most frequent psychiatric syndromes. The median number of psychiatric syndromes was 3 for women and 1 for men (p = 0.007). No correlation between BMI and a single syndrome or the sum of syndromes was observed.Conclusion84 % of the patients seeking bariatric treatment were screened positive for at least one mental health disorder. The computerized PHQ with automated reporting appears to be a useful instrument for presurgical assessment of bariatric patients in routine medical settings.

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Distributed cutaneous tissue blood volume oscillations contain information on autonomic nervous system (ANS) regulation of cardiorespiratory activity as well as dominating thermoregulation. ANS associated with low-frequency oscillations can be quantified in terms of frequencies, amplitudes, and phase shifts. The relative order between these faculties may be disturbed by conditions colloquially termed ‘stress’. Photoplethysmography imaging, an optical non-invasive diagnostic technique provides information on cutaneous tissue perfusion in the temporal and spatial domains. Using the cold pressure test (CPT) in thirteen healthy volunteers as a well-studied experimental intervention, we present a method for evaluating phase shifts in low- and intermediate frequency bands in forehead cutaneous perfusion mapping. Phase shift changes were analysed in low- and intermediate frequency ranges from 0.05 Hz to 0.18 Hz. We observed that time waveforms increasingly desynchronised in various areas of the scanned area throughout measurements. An increase of IM band phase desynchronization observed throughout measurements was comparable in experimental and control group, suggesting a time effect possibly due to overshooting the optimal relaxation duration. CPT triggered an increase in the number of points phase-shifted to the reference that was specific to the low frequency range for phase-shift thresholds defined as π/4, 3π/8, and π/2 rad, respectively. Phase shifts in forehead blood oscillations may infer changes of vascular tone due to activity of various neural systems. We present an innovative method for the phase shift analysis of cutaneous tissue perfusion that appears promising to assess ANS change processes related to physical or psychological stress. More comprehensive studies are needed to further investigate the reliability and physiological significance of findings.

Vagus nerve stimulation (VNS) is used in pharmaco-resistant epilepsy to decrease the number of seizures. Although it is well known that VNS affects respiration, there are only a few reports concerning an effect of VNS on heart rate or heart rate variability (HRV). We investigated the relationship between respiratory frequency and the high frequency (HF) domain of the discrete Fourier transform (DFT) of the RR interval function during night sleep recordings of ten subjects treated with VNS. Our results show that VNS shifts the frequency of maximal power spectrum density (PSD) in the HF-band, decreases the related PSD and induces a partial cardiorespiratory decoupling.