Changes in awakening cortisol response and midnight salivary cortisol are sensitive markers of strenuous training-induced fatigue

The aim of the study was to examine the effects of strenuous training on the hypothalamic- pituitary-adrenal axis activity. Exercise tests and saliva collections for analysis of awakening cortisol response (ACR) and midnight cortisol were performed before and after a 7-day period of intensified training in a group of 15 soccer players. Intensified training resulted in a performance decrement as shown by the pre-post-training changes in maximal values of counter movement jump (CMJ) height (p=0.008). Cortisol assessment during the first 30 min after awakening showed significant increases both before and after the 7-day period and post-training ACR higher than pre-training ACR (p<0.001). Midnight cortisol also significantly increased after training (mean+/-SD, before: 3.0+/-0.7 nmol/l vs after: 5.9+/-3.3 nmol/l; p=0.017). The analysis of individual data showed an important inter-individual variability in the pre-post-training changes: several subjects increased post-awakening peak of cortisol, rate of cortisol increase from awakening to peak, and area under the curve (AUC) values, whereas other subjects showed no training-related increases. Significant correlations were observed between pre-post-training change in CMJ and in the following variables: awakening cortisol (r=0.74), post-awakening peak of cortisol (r=0.81), rate of cortisol increase (r=0.75), and AUC (r=0.79). Briefly, the lower the performance decrease, the higher the training-associated ACR increase. These data could indicate that a dysregulated adaptation to exercise occurred in athletes who experienced a higher performance decrease after training and lower (or absent) hormonal changes. Future studies are needed to elucidate the physiological determinants which underlie the exercise-elicited changes in ACR and in midnight cortisol levels and their value in predicting impaired adaptations to exercise.     

Psychiatric morbidity in stroke patients attending a neurology clinic in Nigeria

Back ground

Stroke produces a wide range of mental and emotional disorders. Neuropsychiatric complications associated with stroke may have negative effects on the social functioning, overall quality of life and the recovery of motor functioning of stroke survivors.

Objective

To determine the prevalence and nature of psychiatric morbidity among stroke patients attending neurology outpatient clinic of the University of Ilorin Teaching Hospital (UITH), Ilorin-Nigeria.

Methods

All patients with stroke aged 18 years and above at an outpatient neurology clinic in Ilorin, Nigeria were assessed for mental and emotional disorders using the Schedule for Clinical Assessment in Neuropsychiatry (SCAN) over one year (March 2009 to February 2010).

Results

Overall prevalence of psychiatric morbidity was 36.0% (30/83) among 83 patients who constituted the study population. Specific diagnoses recorded were depression (19.2%), generalised anxiety disorder (9.6%), harmful alcohol use (2.4%); dementia, somatoform disorder, phobia and delusional disorder each had a prevalence of 1.2%. Clinical and sociodemographic variables were not significantly associated with psychiatric morbidity.

Conclusion

Psychiatric disorders are often associated with stroke. Identifying and treating stroke patients with these psychiatric co-morbidities could thus help to improve the overall quality of life of these patients.     

Serotonin2C receptor localization in GABA neurons of the rat medial prefrontal cortex: implications for understanding the neurobiology of addiction

Serotonin (5-HT) action via the 5-HT(2C) receptor (5-HT(2C)R) provides an important modulatory influence over neurons of the prefrontal cortex (PFC), which is critically involved in disorders of executive function including substance use disorders. In the present study, we investigated the distribution of the 5-HT(2C)R in the rat prelimbic prefrontal cortex (PrL), a subregion of the medial prefrontal cortex (mPFC), using a polyclonal antibody raised against the 5-HT(2C)R. The expression of 5-HT(2C)R immunoreactivity (IR) was highest in the deep layers (layers V/VI) of the mPFC. The 5-HT(2C)R-IR was typically most intense at the periphery of cell bodies and the initial segment of cell processes. Approximately 50% of the 5-HT(2C)R-IR detected was found in glutamate decarboxylase, isoform 67 (GAD 67)-positive neurons. Of the subtypes of GABA interneurons identified by expression of several calcium-binding proteins, a significantly higher percentage of neurons expressing IR for parvalbumin also expressed 5-HT(2C)R-IR than did the percentage of neurons expressing calbindin-IR or calretinin-IR that also expressed 5-HT(2C)R-IR. Since parvalbumin is located in basket and chandelier GABA interneurons which project to cell body and initial axon segments of pyramidal cells, respectively, these results raise the possibility that the 5-HT(2C)R in the mPFC acts via the parvalbumin-positive GABAergic interneurons to regulate the output of pyramidal cells in the rat mPFC.