Stress-induced Fos-like Immunoreactivity in the Pons and the Medulla Oblongata of Rats

Immunoreactivity of the immediate early gene c-fos was used to investigate changes in the activity of brainstem neurons in response to acute stressors like immobilization, formalin-induced pain, cold exposure, hemorrhage and insulin-induced hypoglycemia. Different stressors induced Fos-like immunoreactivity in different pontine and medullary neurons. A single, 3 hour immobilization was found to be a very strong stimulus that activated brainstem catecholaminergic (tyrosine hydroxylase-immunopositive) neurons and cells in the raphe and certain pontine tegmental nuclei, as well as in the reticular formation. Pain, induced by a subcutaneous injection of formalin was also effective on catecholamine-synthesizing neurons and on others cells in the nucleus of the solitary tract. Cold exposure activated cells mainly in the sensory spinal trigeminal and parabrachial nuclei and in the so-called "pontine thermoregulatory area". Moderate Fos-like immunoreactivity was induced by a hypotonic (25%) hemorrhage in medullary catecholaminergic neurons, the nucleus of the solitary tract and the Barrington nucleus. Among stressful stimuli used, insulin-induced hypoglycemia elicited the smallest Fos activation in the lower brainstem. The present observations indicate that different stressors may use different neuronal pathways in the central organization of the stress response.     

Depressive implicit associations and adults' reports of childhood abuse

Theory and research suggest that negative events in childhood (e.g., childhood abuse) may contribute to the development of a cognitive vulnerability to depression. A limitation of past research, however, is that the majority has focused on explicit cognitions (e.g., attributional style) and it remains unclear whether similar relations would be observed for more implicit measures of depressive cognitions. This study investigated the relation between young adults' reports of childhood abuse and their implicit depressive cognitions, as measured by the Implicit Association Test. As hypothesised, young adults reporting a history of childhood abuse exhibited stronger implicit associations for depression-relevant stimuli than did individuals with no abuse history. These results were maintained even after statistically controlling for the influence of current depressive symptom levels.     

Depressive implicit associations and adults' reports of childhood abuse

Theory and research suggest that negative events in childhood (e.g., childhood abuse) may contribute to the development of a cognitive vulnerability to depression. A limitation of past research, however, is that the majority has focused on explicit cognitions (e.g., attributional style) and it remains unclear whether similar relations would be observed for more implicit measures of depressive cognitions. This study investigated the relation between young adults' reports of childhood abuse and their implicit depressive cognitions, as measured by the Implicit Association Test. As hypothesised, young adults reporting a history of childhood abuse exhibited stronger implicit associations for depression-relevant stimuli than did individuals with no abuse history. These results were maintained even after statistically controlling for the influence of current depressive symptom levels.     

Children's 5-HTTLPR genotype moderates the link between maternal criticism and attentional biases specifically for facial displays of anger

Theorists have proposed that negative experiences in childhood may contribute to the development of experience-specific information-processing biases, including attentional biases. There are also clear genetic influences on cognitive processes, with evidence that polymorphisms in specific candidate genes may moderate the impact of environmental stress on attentional biases (e.g., a functional polymorphism in the serotonin transporter gene; 5-HTTLPR). In the current study, we tested a gene×environment (G×E) model of risk for attentional biases. We hypothesised that children whose mothers exhibit high levels of expressed emotion criticism (EE-Crit) would display attentional biases specifically for angry, but not happy or sad, faces, and that this link would be stronger among children carrying one or two copies of the 5-HTTLPR short allele than among those homozygous for the long allele. Results generally supported these hypotheses, though we found that carriers of the 5-HTTLPR short allele who also had a critical mother exhibited attentional avoidance of angry faces rather than preferential attention.