| First Author | Waider J | Year | 2019 |
| Journal | Front Neurosci | Volume | 13 |
| Pages | 245 | PubMed ID | 31068767 |
| Mgi Jnum | J:276143 | Mgi Id | MGI:6313867 |
| Doi | 10.3389/fnins.2019.00245 | Citation | Waider J, et al. (2019) Serotonin Deficiency Increases Context-Dependent Fear Learning Through Modulation of Hippocampal Activity. Front Neurosci 13:245 |
| abstractText | 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. |
