Serotonin Deficiency Increases Context-Dependent Fear Learning Through Modulation of Hippocampal Activity
On: 24 April 2019 26 views
Abstract
Brain serotonin (5-hydroxytryptamine, 5-HT) system dysfunction is implicated in exaggerated fear responses triggering various anxiety-, stress-, and trauma-related disorders. However, the underlying mechanisms are not well understood. Here, we investigated the impact of constitutively inactivated 5-HT synthesis on context-dependent fear learning and extinction using tryptophan hydroxylase 2 (Tph2) knockout mice. Fear conditioning and context-dependent fear memory extinction paradigms were combined with c-Fos imaging and electrophysiological recordings in the dorsal hippocampus (dHip). Tph2 mutant mice, completely devoid of 5-HT synthesis in brain, displayed accelerated fear memory formation and increased locomotor responses to foot shock. Furthermore, recall of context-dependent fear memory was increased. The behavioral responses were associated with increased c-Fos expression in the dHip and resistance to foot shock-induced impairment of hippocampal long-term potentiation (LTP). In conclusion, increased context-dependent fear memory resulting from brain 5-HT deficiency involves dysfunction of the hippocampal circuitry controlling contextual representation of fear-related behavioral responses.
Public information
Title:
Serotonin Deficiency Increases Context-Dependent Fear Learning Through Modulation of Hippocampal Activity
Authors:
Waider Jonas, Popp Sandy, Mlinar Boris, Montalbano Alberto, Bonfiglio Francesco, Aboagye Benjamin, Thuy Elisabeth, Kern Raphael, Thiel Christopher, Araragi Naozumi, Svirin Evgeniy, Schmitt-Böhrer Angelika G., Corradetti Renato, Lowry Christopher A., Lesch Klaus-Peter
Journal:
Frontiers in Neuroscience
Year:
2019
Url:
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