Abnormal Anhedonia as a Potential Endophenotype in Obsessive-Compulsive Disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) is often accompanied by cognitive, particularly executive function, impairments. Recently, anhedonia has emerged as an apparently important symptom of OCD reflecting altered emotion regulation. These two aspects are often comorbid in OCD. However, little is known about whether anhedonia may be a trait marker for OCD. METHODS: To verify the role of executive function and evaluate the role of anhedonia in OCD and its relationship with OCD symptoms, we recruited 60 OCD patients, 30 unaffected first-degree relatives (FDRs), and 60 healthy controls (HCs). Participants completed psychometric testing to assess depression, anxiety, and anhedonia symptoms, as well as two cognitive tests to assess executive function, namely the Wisconsin Card Sorting Test (WCST) and the Stroop Color-Word Test (SCWT). RESULTS: Compared to HCs, OCD patients and FDRs had significantly lower anticipatory and consummatory pleasure scores. The severity of anticipatory anhedonia correlated positively with obsessive-compulsive symptoms (r = 0.253, p = 0.009), even after controlling for depression and anxiety symptoms. Compared to HCs, OCD patients and FDRs made more errors and achieved fewer categories in the WCST. For all three SWCT components, OCD patients and FDRs took more time to name colors than HCs, but the three groups had similar numbers of errors. CONCLUSION: This family-based study showed dampened pleasure together with cognitive dysfunction in OCD patients. The similar consummatory pleasure findings between OCD and FDR groups suggest anhedonia may be considered as a candidate OCD endophenotype.

Atypical longitudinal development of speech-evoked auditory brainstem response in preschool children with autism spectrum disorders.

Language impairment is common in children with autism spectrum disorders (ASDs). Previous research has shown that this disability may be, in part, due to atypical auditory processing of speech stimuli. However, how speech sounds are processed in children with ASD remains largely unknown. The present study assessed the developmental pattern of auditory information processing at the level of the brainstem in preschool children with ASD using speech-evoked auditory brainstem response (speech-ABR). Children with ASD (N = 15) and of typical developing (TD) (N = 20), both of preschool age, were enrolled. The speech-ABRs recorded at two different time points (T1 and T2; 9.68 months apart on average) were virtually identical in the TD group. However, in the ASD group, the wave V latency of speech-ABR was significantly shortened and the amplitudes of wave A and C were significantly larger at T2, compared to those recorded at T1 (10.78 months apart on average). Compared to the TD group, the wave V and A latencies were prolonged at T1, whereas the wave E amplitude decreased and wave F latency prolonged at T2. There was a positive partial correlation between the language performance and the wave A amplitude in the ASD group. These results indicate that auditory processing at the subcortical level is well-developed in the TD preschool children, but is immature and abnormal in the children with ASD at the same ages. Thus, aberrant speech processing at the brainstem level may contribute significantly to the language impairment in children with ASD at preschool ages. Autism Res 2019, 12: 1022-1031. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Language impairment is common in children with autism spectrum disorders (ASDs). We investigated the developmental pattern of subcortical auditory processing by monitoring changes in the speech-evoked auditory brainstem response (speech-ABR) over a period of 10 months in preschool children. Our results show that subcortical auditory processing is impaired and immature in children with ASD compared with age-matched, typically developing children. The results suggest that speech-ABR may be used as an objective measure in evaluating the language performance of children with ASD. The results also suggest that aberrant speech processing at the level of the brainstem may contribute significantly to the language impairment in preschool children with ASD.

Genetic analysis of grain filling rate using conditional QTL mapping in maize.

The grain filling rate (GFR) is an important dynamic trait that determines the final grain yield and is controlled by a network of genes and environment factors. To determine the genetic basis of the GFR, a conditional quantitative trait locus (QTL) analysis method was conducted using time-related phenotypic values of the GFR collected from a set of 243 immortalized F(2) (IF(2)) population, which were evaluated at two locations over 2 years. The GFR gradually rose in the 0-15 days after pollination (DAP) and 16-22 DAP, reaching a maximum at 23-29 DAP, and then gradually decreasing. The variation of kernel weight (KW) was mainly decided by the GFR, and not by the grain filling duration (GFD). Thirty-three different unconditional QTLs were identified for the GFR at the six sampling stages over 2 years. Among them, QTLs qGFR7b, qGFR9 and qGFR6d were identified at the same stages at two locations over 2 years. In addition, 14 conditional QTLs for GFR were detected at five stages. The conditional QTL qGFR7c was identified at stage V|IV (37-43 DAP) at two locations over 2 years, and qGFR7b was detected at the sixth stage (44-50 DAP) in all four environments, except at Anyang location in 2009. QTLs qQTL7b and qQTL6f were identified by unconditional and conditional QTL mapping at the same stages, and might represent major QTLs for regulating the GFR in maize in the IF(2) population. Moreover, most of the QTLs identified were co-located with QTLs from previous studies that were associated with GFR, enzyme activities of starch synthesis, soluble carbohydrates, and grain filling related genes. These results indicated that the GFR is regulated by many genes, which are specifically expressed at different grain filling stages, and the specific expression of the genes between 16-35 DAP might be very important for deciding the final kernel weight.