Brain neurons linked to depression identified

Toronto: Paving the way for new depression treatments, researchers have discovered the first-ever connection between vulnerability to depression and a type of brain cells called noradrenergic neurons. Noradrenergic neurons are located in a cerebral structure named Locus coeruleus.

These neurons communicate with each other using noradrenaline, a neurotransmitter molecule involved in emotional regulation, sleep and mood disorders and the researchers now believe resilience and depression. By combining pharmacological, genetic and optogenetic (activation of the neurons activity by a light beam) approaches, the research team showed that animals that cannot release noradrenaline are systematically vulnerable to depression following chronic stress.

This is not, however, an irreversible condition: increasing noradrenaline production results in higher resilience and less depression, the study said. Stressful life events like job loss, accident, death of a loved one--can trigger major depression in one person, but not in another. A deciding factor is resilience, a biological mechanism that determines an individual's capacity to rebound from stressful or traumatic events.