Chapters authored
Sculpting Cerebral Cortex with Serotonin in Rodent and Primate
The mammalian cerebral cortex is critical for sensory and motor integrations and, for higher-order cognitive functions. The construction of mammalian cortical circuits involves the coordinated interplay between cellular processes such as proliferation, migration and differentiation of neural and glial cell subtypes followed by accurate connectivity evolving in complexity in primates. Alteration in cortical development may induce the emergence of various pathological traits and behaviours. Among the large array of factors that regulate the assembly of cortical circuits, serotonin (5-HT) plays important role as a developmental signal that impacts on a broad diversity of cellular processes. 5-HT plays distinct roles during specific sensitive periods and is produced from various sources depending on the perinatal stage. Its roles are mediated by more than fourteen 5-HT receptors that are all G-protein coupled receptors except the ionotropic 5-HT type 3A receptor (5-HT3A) mediating rapid neuronal activation. Importantly, 5-HT metabolism and signalling are influenced by numerous epigenetic and genetic factors, including nutrition and gut microbiota, perinatal stress, infection and inflammation. In this review, we will recapitulate some evidences showing that dysregulation of 5-HT homeostasis and 5-HT3A signalling impairs distinct steps of cortical circuit formation leading to the predisposition of the onset of various psychiatric diseases.
Part of the book: Serotonin
Roles of the Serotoninergic System in Coping with Traumatic Stress
Post-Traumatic Stress Disorder (PTSD) is characterized by substantial physiological and/or psychological distress following exposure to trauma. Intrusive fear memories often lead to persistent avoidance of stimuli associated with the trauma, detachment from others, irritability and sleep disturbances. Different key structures in the brain are involved with fear conditioning, fear extinction and coping. The limbic system, namely, the amygdala complex in close relationship with the hippocampal hub and the prefrontal cortex play central roles in the integration and in coping with fear memories. Serotonin acting both as a neurotransmitter and as a neurohormone participates in regulating the normal and pathological activity of these anatomic structures. We review the literature analyzing how the different actors of the serotoninergic system (5-HT receptors, transporters and anabolic and catabolic pathways) may be involved in regulating the sensitivity to highly stressful events and hopefully coping with them.
Part of the book: Serotonin and the CNS