Biological psychiatry
-
Biological psychiatry · Aug 2014
Toll-like receptor 4 regulates chronic stress-induced visceral pain in mice.
Functional gastrointestinal disorders, which have visceral hypersensitivity as a core symptom, are frequently comorbid with stress-related psychiatric disorders. Increasing evidence points to a key role for toll-like receptor 4 (TLR4) in chronic pain states of somatic origin. However, the central contribution of TLR4 in visceral pain sensation remains elusive. ⋯ Our results reveal a novel role for TLR4 within the PFC in the modulation of visceral nociception and point to TLR4 as a potential therapeutic target for the development of drugs to treat visceral hypersensitivity.
-
Biological psychiatry · Aug 2014
Amnesia for early life stress does not preclude the adult development of posttraumatic stress disorder symptoms in rats.
Traumatic experience can result in life-long changes in the ability to cope with future stressors and emotionally salient events. These experiences, particularly during early development, are a significant risk factor for later life anxiety disorders such as posttraumatic stress disorder (PTSD). However, because traumatic experience typically results in strong episodic memories, it is not known whether such long-term memories are necessary for particular features of PTSD, such as enhanced fear and anxiety. Here, we used a fear conditioning procedure in juvenile rats before maturation of the neural systems supporting declarative memory to assess the necessity of early memory to the later life development of PTSD-related symptoms. ⋯ These results suggest that traumatic experience during developmental periods of hippocampal immaturity can promote lifelong changes in symptoms and neuropathology associated with human PTSD, even if there is no explicit memory of the early trauma.
-
Biological psychiatry · Aug 2014
Dysfunctional glutamatergic and γ-aminobutyric acidergic activities in prefrontal cortex of mice in social defeat model of depression.
Depression is a complex neuropsychiatric syndrome that is often very severe and life threatening. In spite of the remarkable progress in understanding the neural biology, the etiopathophysiology of depression is still elusive. In this study, we have investigated molecular mechanisms in the prefrontal cortex of mice showing depression-like phenotype induced by chronic defeat stress. ⋯ These data indicate that the activities of glutamatergic and GABAergic neurons are reduced in mice showing a depression-like phenotype, which is supported by molecular data for the expression of genes involved in glutamate and GABA pathways.