Effects of environmental stress on the depression-like behaviors and the diurnal rhythm of corticosterone and melatonin in male rats.

Environmental stress (ES) is commonly used in producing chronic unpredictable mild stress to study pathogenesis of depression, including the regulatory role of circadian system on depression. However, the direct effect of ES on the circadian system has been rarely explored. The present study was aimed to investigate the effect of ES on depression-like behaviors and diurnal rhythm of plasma hormone/peptide levels in male rats. Rats were allocated into control group (CON group), low frequency ES group (LF group) and high frequency ES group (HF group). Sucrose preference test (SPT), open field test (OFT), weight gain, food and water intake were conducted to assess depression- and anxiety-like behaviors. A total of 7 times of the tail venous blood was collected with an interval of 4 h during 24 h from other rats who subjected to the same procedures of ES but not the behavioral tests. The alterations of diurnal rhythm of peripheral plasma corticosterone (CORT) and melatonin, and changes of the cholecystokinin (CCK), neuropeptide Y and leptin levels at zeitgeber time (ZT) 0 were detected by using enzyme-linked immunosorbent assay (ELISA). We found that ES led to a disturbance of diurnal rhythm of CORT and melatonin in the plasma. Besides, it also increased plasma leptin level and decreased body weight gain, but it did not produce depression- and anxiety-like behaviors compared with those rats in the control group. In short, our findings indicated that the ES could induce a disturbance of diurnal rhythm of plasma CORT and melatonin in male rats.

Alterations of the daily rhythms of HPT axis induced by chronic unpredicted mild stress in rats.

The relationship between thyroid function and depression has long been recognized. Patients with thyroid disorders are more prone to develop depressive symptoms and conversely depression may be accompanied by various subtle thyroid abnormalities. However, the daily rhythm alteration of the functions of the hypothalamus pituitary thyroid axis (HPT) is uncertain. In the present study, we investigated the effects of chronic unpredictable mild stress (CUMS) on the daily rhythm alterations of triiodothyronine (T3), thyroxine (T4), and Thyroid Stimulating Hormone (TSH) in the plasma. We found that CUMS led to depressive-like behavior and the daily rhythm of T3, T4, and TSH in the plasma being disturbed, as well the plasma levels of T3 and T4 decreased compared to control group. Our findings indicate that CUMS not only induce hypofunction of HPT axis but also the disturbance of daily rhythm of PHT axis in rats.

[Analysis on neuropsychological characteristics of subtypes of attention deficit hyperactivity disorder].

OBJECTIVE: To explore the neuropsychological characteristics of children with attention deficit hyperactivity disorder (ADHD). METHODS: Neuropsychological tests, including visual working memory, Stroop test, digits inverse reciting, vocabulary fluency, Wisconsin card sort test (WCST), and Temporal discounting were used to evaluate the capacity of response inhibition, phonological working memory, visual working memory executive function and delayed satisfying capacity of subjects. RESULTS: 1. The ADHD children spent longer time [ADHD-I (84(20), ADHD-C: 98 (31), normal: 70 (28)] to accomplish color naming and made more errors [ADHD-I: 3 (3), ADHD-C: 6 (19), normal: 2 (5)] than the normal control when the color was inconsistent with the word meaning in Stroop test (P < 0.01). 2. The scores of digits reciting [ADHD-I: 3 (3), ADHD-C: 3 (4), normal 4 (4)] inverse was lower in ADHD than in normal control (P < 0.01). 3. The representation of ADHD was poorer than normal control in visual working memory [ADHD-I: 21 (3), ADHD-C: 20 (5), Normal: 20 (3)], and in delayed visual memory [ADHD-I: 19 (5), ADHD-C: 19 (5), Normal: 20 (5)] (P < 0.01). 4. The scores of vocabulary fluency [ADHD-I: 1 (1), ADHD-C: 2 (1), normal: 0 (0)] was lower in ADHD than in normal control (P < 0.01). 5. In WCST, the ADHD children made more errors [ADHD-I :15 (17), ADHD-C: 15 (15), normal: 13 (13)] and less classification [ADHD-I: 5 (4), ADHD-C: 5 (4), normal: 5 (3)] than normal control (P < 0.01). 6. In Temporal discounting, the ADHD children showed significantly more impairments than normal control did (P < 0.01). 7. There was significant difference between the two subtype groups on some tests (P < 0.01). CONCLUSIONS: Obvious cognitive impairments were found in children with ADHD, involving poor response inhibition, impaired working memory, dysfunction of planning and set-shifting, and there was no significant difference between the two subtype groups.

[The intelligence characteristics of the head traumatic children].

OBJECTIVE: To explore characteristics of the head traumatic children's intelligence. METHODS: The authors investigated 43 head trauma children and 50 normal children, using Wechser Intelligence Test (C-WISC). Data were analyzed by SPSS10.0 on computer. RESULTS: Head trauma children had lower FIQ, VJQ, PIQ than normal children. Pervaded head trauma has more contribution to the damage of the children's intelligence.