Anxiolytic treatment of a trapped rat reduces helping and anxiogenic treatment increases helping: Evidence for emotional contagion in altruism.

The present experiment used the trapped rat model to explore whether pharmacological manipulation of distress affects the likelihood of helping behavior. 120 Sprague-Dawley rats (30 male pairs and 30 female pairs) completed 12 consecutive, daily trials assessing helping behavior. During an individual trial, a trapped rat was placed in a restrainer in the center of an open field, while its cagemate could move around freely and possibly open the restrainer by lifting a door.

Amygdala and hippocampal substructure volumes and their association with improvement in mood symptoms in patients with mood disorders undergoing electroconvulsive therapy.

Electroconvulsive therapy (ECT) demonstrates favorable outcomes in the management of severe depressive disorders. ECT has been consistently associated with volumetric increases in the amygdala and hippocampus. However, the underlying mechanisms of these structural changes and their association to clinical improvement remains unclear.