Brain serotonin reuptake did not change during one year in overtrained athletes.

Brain 5-HT neurotransmission has been described to be down-regulated in depressed people, and also suspected to be changed in overtraining state, the consequence of long-term physical overloading and stress in athletes. We studied brain serotonin (5-HT) transporter binding i.e., 5-HT reuptake with the specific radioligand (123-I-labelled 2beta-carbomethoxy-3beta[4-iodopenyl]-nortropane, Nor-beta-CIT), and with single photon emission tomography (SPET) in severely overtrained athletes and their controls at the baseline and after a one-year recovery period. Twelve overtrained (6 women and 6 men, mean age 27 yrs, range 16 - 39 yrs) and 11 healthy (6 women, 5 men, 26 yrs, 20 - 39 yrs) athletes were examined. Overtrained athletes 1) had suffered from an unexplained decrement in physical performance and fatigue for several weeks to many months and continued to have the same symptoms even after a recovery time of weeks to months, 2) had been examined to be otherwise healthy, and 3) had a suitable training history for overtraining. Nor-beta-CIT SPET was acquired 5 min, and 3, 6, and 24 h after the injection of the radioligand. 5-HT reuptake in ml/ml in midbrain (raphe nuclei) was calculated as (midbrain - cerebellum)/cerebellum. According to two-way analysis of variance, no changes inside the groups or group differences in 5-HT reuptake were found. Male athletes had significantly higher 5-HT reuptake than female athletes at the baseline (p = 0.034). The overtrained athletes were moderately depressed, while their scores in standardized Hamilton and Montgomery-Asberg Depression Rating Scales were 16 +/- 2 (mean +/- SEM, range 8 - 29) and 17 +/- 2 (7 - 28), respectively. In the CA, the scores were 6 +/- 1 (range 2 - 18) and 6 +/- 2 (1 - 19), respectively. 5-HT reuptake did not correlate with the depression scores either in the whole group or in the OA. The finding of the present study does not support the idea of long-term changes in 5-HT neurotransmission in overtraining state, in this case serotonin reuptake in midbrain, the regulating area of brain serotonin neurotransmission. Furthermore, depression of overtrained athletes may be its own variant having no correlation with 5-HT reuptake in midbrain. Sex may have effect on chronic stress response at the brain level in athletes, which may be a confusing factor in the overtraining studies, and has to be taken into consideration in the future.

On correlation between single-trial ERP and GSR responses: a principal component regression approach.

In this study we investigate the correlation between single-trial evoked brain responses and galvanic skin responses (GSR). The correlation between the two signals is examined by using a modified principal component regression based approach. A potential application of the study is to utilize the GSR measurements in a form of a prior information in the estimation of the brain potentials when only small number of trials is available.

Abnormal serotonin reuptake in an overtrained, insomnic and depressed team athlete.

The purpose of this report is to study serotonin reuptake of the brain in a severely overtrained athlete by using single-photon emission computed tomography (SPECT). A 26-year-old team athlete increased his training volume (by 200 %) and intensity markedly in a new high-level team. After two months, he started to feel continuous fatigue. He had tinnitus in his left ear, he felt disturbing palpitation and had pollacisuria. After four months, he started to suffer from insomnia. He still continued to play for another three months, after which he was unable to play. He could only sleep for 3 to 4 hours per night. Only minor abnormalities could be found in extensive physical and laboratory examinations. The athlete had a severe overtraining state. In the brain SPECT scans, using the specific radioligand for serotonin transporter imaging ( (123)I labelled 2beta-carbomethoxy-3beta-[4-iodophenyl]-nortropane), low activity areas were detected in the midbrain, anterior gingulus, and left frontal and temporo-occipital lobes. In a psychiatric examination, the patient was found to have signs of major depression, which he hardly recognized himself. We conclude, that that the severe overtraining state could have been related to decreased serotonin reuptake in the brain and signs of major depression.

Analysis of galvanic skin responses with principal components and clustering techniques.

An advanced method for analyzing the patterning of successive galvanic skin responses (GSR) is presented. The proposed method is based on principal component analysis in which the vector containing the measured signal is presented as a weighted sum of orthogonal basis vectors. The method is tested using measurements from 20 healthy controls and 13 psychotic patients. For each subject, 11 surprising auditory stimuli were delivered to right ear at irregular intervals and evoked GSRs were recorded from the hand. For most of the healthy controls, there was a clear pattern in successive GSRs, whereas within psychotic patients the lack of time-locking of GSRs seemed to be characteristical. These between group differences can be revealed by the proposed method. With application to clustering a significant discrimination, with overall correct ratings of 82%, of healthy controls and psychotic patients is achieved. A significant fact is that all patients were ranked correctly giving the proposed method a sensitivity of 100%.

SPECT and neuropsychological performance in severe depression treated with ECT.

BACKGROUND: In severe depression, studies of regional cerebral blood flow (rCBF) by SPECT have not produced uniform results. The association between changes in SPECT and electroconvulsive therapy (ECT) has shown somewhat conflicting data. No data are available on benzodiazepine receptor function SPECT studies in ECT. METHODS: Twenty drug-resistant adult inpatients fulfilling the DSM-IIIR criteria for major depression were studied by SPECT (rCBF by relative ECD uptake in all, and benzodiazepine receptor function by iomazenil uptake in five subjects) before and 1 week after clinically successful bitemporal ECT. Clinical and neuropsychological test scores were used as references for the possible changes in SPECT. RESULTS: An increased perfusion after ECT was observed in right temporal and bilateral parietal cortices, whereas no reductions in relative ECD uptake were seen after ECT. Iomazenil-SPECT revealed a highly significant increase in the benzodiazepine receptor uptake in all studied cortical regions except temporal cortices. CONCLUSIONS: Clinically successful ECT was associated with changes in vascular perfusion and GABAergic neurotransmission, providing new evidence for the mechanism of action of ECT and for the neurobiology of severe drug-resistant depression.

Loss of time-organized sympathetic skin responses in acute psychosis.

The aim of this study was to differentiate the response pattern characteristics of sympathetic skin responses (SSR) between unmedicated first psychotic subjects and healthy controls. We recorded SSR to novel auditory stimuli in 13 psychotic subjects and in 19 controls. There was no constant delay between a sudden change in the acoustic surroundings and SSR in psychotic subjects, whereas regularly this delay was 1.3 to 1.8 seconds in controls. The validity of the test was evaluated by blind rating responses to two categories. The lack of a regular time delay between a novel auditory stimulus and SSR suggests a timing disturbance in the neural networks regulating the autonomic nervous system responses in acute psychosis. Our finding and method may have future implications in evaluation of subtle autonomic nervous system alterations related, e.g., to drug effects.

Quantitative MRI of the hippocampus and amygdala in severe depression.

BACKGROUND: There is little evidence to support possible structural changes in the amygdala and hippocampus of patients with severe depression. METHODS: Quantitative MRI of the amygdala and hippocampus, as well as proton spectroscopy (MRS) of mesial temporal structures were studied in 34 drug-resistant in-patients with major depression and compared with 17 age-matched controls. Volumetric MRI data were normalized for brain size. RESULTS: The volume of the left hippocampus was significantly smaller in the patients compared with the controls. Both groups exhibited similar significant hippocampal asymmetry (left smaller than right). The patients, but not the controls, had significant asymmetry of the amygdalar volumes (right smaller than left). No differences were observed between the patients and controls in the T2 relaxation times for the hippocampus and amygdala. Mesial temporal lobe MRS revealed a significantly elevated choline/creatine ratio in the patients compared with the controls. CONCLUSIONS: This quantitative MRI study provides support for a possible association between structural and biochemical substrates and severe drug-resistant major depression.