0000000000040412
AUTHOR
Carmen Sandi
Macrophage migration inhibitory factor is critically involved in basal and fluoxetine-stimulated adult hippocampal cell proliferation and in anxiety, depression, and memory-related behaviors
Intensive research is devoted to unravel the neurobiological mechanisms mediating adult hippocampal neurogenesis, its regulation by antidepressants, and its behavioral consequences. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is expressed in the CNS, where its function is unknown. Here, we show, for the first time, the relevance of MIF expression for adult hippocampal neurogenesis. We identify MIF expression in neurogenic cells (in stem cells, cells undergoing proliferation, and in newly proliferated cells undergoing maturation) in the subgranular zone of the rodent dentate gyrus. A causal function for MIF in cell proliferation was shown using genetic (M…
Long term effects of peripubertal stress on excitatory and inhibitory circuits in the prefrontal cortex of male and female mice.
Abstract The impact of stressful events is especially important during early life, because certain cortical regions, especially the prefrontal cortex (PFC), are still developing. Consequently, aversive experiences that occur during the peripubertal period can cause long-term alterations in neural connectivity, physiology and related behaviors. Although sex influences the stress response and women are more likely to develop stress-related psychiatric disorders, knowledge about the effects of stress on females is still limited. In order to analyze the long-term effects of peripubertal stress (PPS) on the excitatory and inhibitory circuitry of the adult PFC, and whether these effects are sex-d…
Neuropharmacology of the mesolimbic system and associated circuits on social hierarchies
Most socially living species are organized hierarchically, primarily based on individual differences in social dominance. Dominant individuals typically gain privileged access to important resources, such as food, mating partners and territories, whereas submissive conspecifics are often devoid of such benefits. The benefits associated with a high social status provide a strong incentive to become dominant. Importantly, motivational- and reward-related processes are regulated, to a large extent, by the mesolimbic system. Consequently, several studies point to a key role for the mesolimbic system in social hierarchy formation. This review summarizes the growing body of literature that implic…
GABAA receptors in the ventral tegmental area control the outcome of a social competition in rats
Social dominance can be attained through social competitions. Recent work in both humans and rodents has identified trait anxiety as a crucial predictor of social competitiveness. In addition, the anxiolytic GABAA positive modulator, diazepam, injected either systemically or into the ventral tegmental area (VTA) was shown to increase social dominance. Here, we investigated the impact of pharmacologically targeting GABAA receptors in the VTA for the outcome of a social competition between two unfamiliar male rats, one of them infused with vehicle and the other one with the drug under study. We show that infusion of the GABAA receptor agonist, muscimol, reduced anxiety-like behaviors and enha…
Long-Term Behavioral Programming Induced by Peripuberty Stress in Rats Is Accompanied by GABAergic-Related Alterations in the Amygdala
Stress during childhood and adolescence is a risk factor for psychopathology. Alterations in γ-aminobutyric acid (GABA), the main inhibitory neurotransmitter in the brain, have been found following stress exposure and fear experiences and are often implicated in anxiety and mood disorders. Abnormal amygdala functioning has also been detected following stress exposure and is also implicated in anxiety and social disorders. However, the amygdala is not a unitary structure; it includes several nuclei with different functions and little is known on the potential differences the impact of early life stress may have on this system within different amygdaloid nuclei. We aimed here to evaluate pote…
Impaired hippocampal neuroligin-2 function by chronic stress or synthetic peptide treatment is linked to social deficits and increased aggression.
Neuroligins (NLGNs) are cell adhesion molecules that are important for proper synaptic formation and functioning, and are critical regulators of the balance between neural excitation/inhibition (E/I). Mutations in NLGNs have been linked to psychiatric disorders in humans involving social dysfunction and are related to similar abnormalities in animal models. Chronic stress increases the likelihood for affective disorders and has been shown to induce changes in neural structure and function in different brain regions, with the hippocampus being highly vulnerable to stress. Previous studies have shown evidence of chronic stress-induced changes in the neural E/I balance in the hippocampus. Ther…
Role of the amygdala in antidepressant effects on hippocampal cell proliferation and survival and on depression-like behavior in the rat
The stimulation of adult hippocampal neurogenesis by antidepressants has been associated with multiple molecular pathways, but the potential influence exerted by other brain areas has received much less attention. The basolateral complex of the amygdala (BLA), a region involved in anxiety and a site of action of antidepressants, has been implicated in both basal and stress-induced changes in neural plasticity in the dentate gyrus. We investigated here whether the BLA modulates the effects of the SSRI antidepressant fluoxetine on hippocampal cell proliferation and survival in relation to a behavioral index of depression-like behavior (forced swim test). We used a lesion approach targeting th…
Neuroligin-2 Expression in the Prefrontal Cortex is Involved in Attention Deficits Induced by Peripubertal Stress
Emerging evidence indicates that attention deficits, which are frequently observed as core symptoms of neuropsychiatric disorders, may be elicited by early life stress. However, the mechanisms mediating these stress effects remain unknown. The prefrontal cortex (PFC) has been implicated in the regulation of attention, including dysfunctions in GABAergic transmission, and it is highly sensitive to stress. Here, we investigated the involvement of neuroligin-2 (NLGN-2), a synaptic cell adhesion molecule involved in the stabilization and maturation of GABAergic synapses, in the PFC in the link between stress and attention deficits. First, we established that exposure of rats to stress during th…