Neurons that synthesize and release 5-hydroxytryptamine (5-HT; serotonin) express a core
set of genes that establish and maintain this neurotransmitter phenotype and distinguish …

Chronic stressful life events are risk factors for developing major depression, the
pathophysiology of which is strongly linked to impairments in serotonin (5-HT) …

Prolonged behavioral challenges can cause animals to switch from active to passive coping
strategies to manage effort-expenditure during stress; such normally adaptive behavioral …

The role of serotonin in depression and antidepressant treatment remains unresolved
despite decades of research. In this paper, we make three major claims. First, serotonin …

Research has elucidated causal links between stress exposure and the development of
anxiety disorders, but due to the limited use of female or sex-comparative animal models …

Learned helplessness, the failure to escape shock induced by uncontrollable aversive
events, was discovered half a century ago. Seligman and Maier (1967) theorized that …

The degree of behavioral control that an organism has over a stressor is a potent modulator
of the stressor's impact; uncontrollable stressors produce numerous outcomes that do not …

In this review, we discuss the usefulness of the distinction between fear and anxiety. The
clinical use of the labels is ambiguous, often defining one in terms of the other. We first …

The term 'learned helplessness' refers to a constellation of behavioral changes that follow
exposure to stressors that are not controllable by means of behavioral responses, but that …

Affective valence lies on a spectrum ranging from punishment to reward. The coding of such
spectra in the brain almost always involves opponency between pairs of systems or …