Adolescent social isolation induces sex-specific behavioral and neural alterations.

Adversities associated with isolation during adolescence, including the lack of appropriate emotional and social experiences, can jeopardize the individual development leading to the onset of mental illnesses such as major depressive disorder. Girls have higher rates of depression compared to boys; however, the relative contribution of biological and cultural factors to such a gender-dependent difference remains unclear. To identify the role of biological factors in this distinct susceptibility, we exposed adolescent C57BL/6 male and female mice (n = 12-14) to social isolation and we evaluated their behavioral responses, investigating both emotional and cognitive competencies during adolescence.

Subjective experience of the environment determines serotoninergic antidepressant treatment outcome in male mice.

Background: The effects of the selective serotonin reuptake inhibitors (SSRIs), the first-line antidepressant treatment, have been proposed to be affected, at least in part, by the living environment. Since the quality of the environment depends not only on its objective features, but also on the subjective experience, we hypothesized that the latter plays a key role in determining SSRI treatment outcome.

Methods: We chronically administered the SSRI fluoxetine to two groups of adult CD-1 male mice that reportedly show distinct subjective experiences of the environment measured as consistent and significantly different responses to the same emotional and social stimuli.

Minocycline treatment improves cognitive and functional plasticity in a preclinical mouse model of major depressive disorder.

Major depressive disorder (MDD) is a chronic, recurring, and potentially life-threatening illness, which affects over 300 million people worldwide. MDD affects not only the emotional and social domains but also cognition. However, the currently available treatments targeting cognitive deficits in MDD are limited.

Microglial-glucocorticoid receptor depletion alters the response of hippocampal microglia and neurons in a chronic unpredictable mild stress paradigm in female mice.

Chronic psychological stress is one of the most important triggers and environmental risk factors for neuropsychiatric disorders. Chronic stress can influence all organs via the secretion of stress hormones, including glucocorticoids by the adrenal glands, which coordinate the stress response across the body. In the brain, glucocorticoid receptors (GR) are expressed by various cell types including microglia, which are its resident immune cells regulating stress-induced inflammatory processes.

Selecting antidepressants according to a drug-by-environment interaction: A comparison of fluoxetine and minocycline effects in mice living either in enriched or stressful conditions.

Selective serotonin reuptake inhibitors (SSRIs) are the first-line treatment for major depressive disorder. It has been recently proposed that these drugs, by enhancing neural plasticity, amplify the influences of the living conditions on mood. Consequently, SSRI outcome depends on the quality of the environment, improving symptomatology mainly in individuals living in favorable conditions.

Interplay between inflammation and neural plasticity: Both immune activation and suppression impair LTP and BDNF expression.

An increasing number of studies show that both inflammation and neural plasticity act as key players in the vulnerability and recovery from psychiatric disorders and neurodegenerative diseases. However, the interplay between these two players has been limitedly explored. In fact, while a few studies reported an immune activation, others conveyed an immune suppression, associated with an impairment in neural plasticity.