A systematic review of studies utilizing hair glucocorticoids as a measure of stress suggests the marker is more appropriate for quantifying short-term stressors.

Quantitating glucocorticoids (GCs) in hairs is a popular method for assessing chronic stress in studies of humans and animals alike. The cause-and-effect relationship between stress and elevated GC levels in hairs, sampled weeks later, is however hard to prove. This systematic review evaluated the evidence supporting hair glucocorticoids (hGCs) as a biomarker of stress.

Comparison of commercial ELISA assays for quantification of corticosterone in serum.

Enzyme-linked immunosorbent assay (ELISA) kits are widely used to quantify corticosterone levels for the assessment of stress in laboratory animals. The aim of this experiment was simply to evaluate if four different and widely used commercial ELISA assays would yield the same or similar values of corticosterone in serum samples taken from laboratory rats after the mild stress of being held for sampling blood from the saphenous vein. Trunk blood was sampled from 32 male Wistar rats 30 minutes after this mild stress exposure and analysed with each of four commercial ELISA kits.

Early developmental, temperamental and educational problems in 'substance use disorder' patients with and without ADHD. Does ADHD make a difference?

Introduction: The prevalence of ADHD among patients with substance use disorder (SUD) is substantial. This study addressed the following research questions: Are early developmental, temperamental and educational problems overrepresented among SUD patients with ADHD compared to SUD patients without ADHD? Do this comorbid group receive early help for their ADHD, and are there signs of self-medicating with illicit central stimulants?

Method: An international, multi-centre cross-sectional study was carried out involving seven European countries, with 1205 patients in treatment for SUD. The mean age was 40 years and 27% of the sample was female.

Effects of social defeat on sleep and behaviour: importance of the confrontational behaviour.

We studied the short- and long-term effects of a double social defeat (SD) on sleep parameters, EEG power, behaviour in the open field emergence test, corticosterone responsiveness, and acoustic startle responses. Pre-stress levels of corticosterone were assessed before all rats were surgically implanted with telemetric transmitters for sleep recording, and allowed 3weeks of recovery. Rats in the SD group (n=10) were exposed to 1hour SD on two consecutive days, while control rats (n=10) were left undisturbed.

Early and later life stress alter brain activity and sleep in rats.

Exposure to early life stress may profoundly influence the developing brain in lasting ways. Neuropsychiatric disorders associated with early life adversity may involve neural changes reflected in EEG power as a measure of brain activity and disturbed sleep. The main aim of the present study was for the first time to characterize possible changes in adult EEG power after postnatal maternal separation in rats.

Long-term effects of environmentally relevant doses of 2,2',4,4',5,5' hexachlorobiphenyl (PCB153) on neurobehavioural development, health and spontaneous behaviour in maternally exposed mice.

Background: Polychlorinated biphenyls (PCBs) are widespread in the environment, human food and breast milk. Seafood is known to contain nutrients beneficial for the normal development and function of the brain, but also contaminants such as PCBs which are neurotoxic. Exposure to non-coplanar PCBs during brain development can disrupt spontaneous behaviour in mice and lead to hyperactive behaviour.

Behavioral effects of 7-nitroindazole on hyperbaric oxygen toxicity.

The aim of this study was to evaluate the role of nitric oxide (NO) upon hyperbaric oxygen (HBO) toxicity in male Sprague-Dawley rats during exposure to 0.5 MPa >99% O(2). In the first experiment, the selective neuronal NO synthase inhibitor 7-nitroindazole (7-NI) was injected intraperitoneally (ip) in 15 rats.