Search

Childhood conduct disorder (CD) may originate in a stressful upbringing, and be associated with unusual physical or sexual development and thyroid dysfunction. We therefore explored circulating levels of hormones from adrenal, gonadal and growth hormone axes associated with stress, aggression and development in 28 CD patients and 13 age-matched healthy children (10-18 years old). The CD group had higher levels of dehydroepiandrosterone sulphate (DHEA-S), corticotropin (ACTH) and free tri-iodothyronine (fT(3)) if under 14 years. There were no differences for gonadal hormones or maturity ratings which were not associated with aggression. Smaller physical measures in CD children correlated with DHEA-S and growth factors (e.g. insulin-like growth factor I) increased ACTH and fT(3) correlated with restless-impulsive ratings, and DHEA-S with 'disruptive behaviour'. Imbalances in the adrenal and growth axes may have neurotropic repercussions in development., (Copyright 2001 S. Karger AG, Basel)

Locomotor activity was automatically recorded in a circular corridor in rats treated with 6-hydroxydopamine in the ventral tegmental area (VTA), septum and frontal cortex. Control and experimental groups showed similar hyperlocomotor responses in the novel apparatus lasting 3 h. Circadian changes are described. VTA lesions resulted in increased dark activity and a large response to apomorphine compared to other lesion and control groups. Septal lesions did not affect locomotion. The frontal group showed a small increase of locomotion after apomorphine treatment that might reflect increased receptor sensitivity in cortical or subcortical areas. Together with correlations between motor activity and cortical levels of dopamine and noradrenaline these results are interpreted to support a role for dopamine, noradrenaline and the frontal cortex in modulating locomotion which is primarily mediated by VTA-accumbens-dopamine activity.

Chicks with dorsal midline hyperstriatal lesions (DMHA) were trained to prefer red to yellow food before being presented with a choice from a plain floor (experiment 1) or a pebble-encrusted floor (experiment 2). On both tests DMHAs showed a relatively stable pattern of choice compared to controls. In experiment 1, controls decreased their intake of non-preferred yellow food on day 1, but this sharply increased on subsequent tests. In experiment 2, controls increased the number of pebbles pecked, and thus, the length of a run of pecks on non-preferred food changed with respect to DMHAs. Chicks with more lateral lesions gave patterns distinct from controls and DMHAs showing an initial disruption of the trained preference. The choice of chicks with more ventral or posterior lesions could not be distinguished from controls. The lack of lability of the trained feeding behavior of DMHA-lesioned chicks is interpreted as consistent with the suggestion that the DMHA may have functions which are similar to the "hippocampus" of mammals.