Neuroimaging studies of depression considered as a stress-related disorder have shown uncoupling in regional cerebral blood flow (rCBF) and regional cerebral metabolic rate for glucose (rCMRglc). We hypothesised that the mismatch change of rCBF and rCMRglc could be a stress-related phenomenon.

We exposed male rats to 15-min period of forced swim (FS), followed by the measurement of rCBF using N-isopropyl-4-[123I] iodoamphetamine (123I-IMP) and rCMRglc using 2-deoxy-2-[18F] fluoro-D-glucose (18F-FDG).

The uptake rate of 18F-FDG in the FS group showed a significant decrease in the prefrontal cortex (0.86±0.20%ID/g, p<0.01) and thalamus (0.77±0.17%ID/g, p<0.05) and tended to be lower in the hippocampus (0.58±0.13%ID/g) and cerebellum (0.59±0.13%ID/g) without overt alteration in the uptake rate of 123I-IMP.

The FS stress can cause mismatch change of rCBF and rCMRglc, which reflect a stress-related phenomenon.

Previous studies have reported the association between advanced paternal age at birth and the risk of autistic-spectrum disorder in offspring, including offspring with intellectual disability.

To test whether an association between advanced paternal age at birth is found in offspring with high-functioning autistic-spectrum disorder (i.e. offspring without intellectual disability).

A case–control study was conducted in Japan. The participants consisted of individuals with full-scale IQ ⩾ 70, with a DSM–IV autistic disorder or related diagnosis. Unrelated healthy volunteers were recruited as controls. Parental ages were divided into tertiles (i.e. three age classes). Odds ratios and 95% confidence intervals were estimated using logistic regression analyses, with an adjustment for age, gender and birth order.

Eighty-four individuals with autistic-spectrum disorder but without intellectual disability and 208 healthy controls were enrolled. Increased paternal, but not maternal, age was associated with an elevated risk of high-functioning autistic-spectrum disorder. A one-level advance in paternal age class corresponded to a 1.8-fold increase in risk, after adjustment for covariates.

Advanced paternal age is associated with an increased risk for high-functioning autistic-spectrum disorder.