Inhibitory synaptic transmissions to the bed nucleus of the stria terminalis neurons projecting to the ventral tegmental
- PDF / 1,038,675 Bytes
- 5 Pages / 595.276 x 790.866 pts Page_size
- 45 Downloads / 166 Views
Open Access
MICRO REPORT
Inhibitory synaptic transmissions to the bed nucleus of the stria terminalis neurons projecting to the ventral tegmental area are enhanced in rats exposed to chronic mild stress Ryuto Hara, Daiki Takahashi, Tatsuhiro Takehara, Taiju Amano and Masabumi Minami*
Abstract The comorbidities of depression and chronic pain have long been recognized in the clinic, and several preclinical studies have demonstrated depression-like behaviors in animal models of chronic pain. These findings suggest a common neuronal basis for depression and chronic pain. Recently, we reported that the mesolimbic dopaminergic system was tonically suppressed during chronic pain by enhanced inhibitory synaptic inputs to neurons projecting from the dorsolateral bed nucleus of the stria terminalis (dlBNST) to the ventral tegmental area (VTA), suggesting that tonic suppression of the mesolimbic dopaminergic system by this neuroplastic change may be involved in chronic pain-induced depression-like behaviors. In this study, we hypothesized that inhibitory synaptic inputs to VTAprojecting dlBNST neurons are also enhanced in animal models of depression, thereby suppressing the mesolimbic dopaminergic system. To test this hypothesis, we performed whole-cell patch-clamp electrophysiology using brain slices prepared from rats exposed to chronic mild stress (CMS), a widely used animal model of depression. The results showed a significant enhancement in the frequency of spontaneous inhibitory postsynaptic currents in VTA-projecting dlBNST neurons in the CMS group compared with the no stress group. The findings revealed enhanced inhibitory synaptic inputs to VTA-projecting dlBNST neurons in this rat model of depression, suggesting that this neuroplastic change is a neuronal mechanism common to depression and chronic pain that causes dysfunction of the mesolimbic dopaminergic system, thereby inducing depression-like behaviors. Keywords: Bed nucleus of the stria terminalis, Chronic mild stress, Chronic pain, Depression Introduction The comorbidities of depression and chronic pain have long been recognized in the clinic [1], and several preclinical studies have shown depression-like behaviors in animal models of chronic pain [2]. These findings suggest a common neuronal basis for depression and chronic pain. The mesolimbic dopaminergic pathway from the ventral tegmental area (VTA) to the nucleus accumbens *Correspondence: [email protected] Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060‑0812, Japan
(NAc) is a key player in the mesolimbic reward circuit, and dysfunction in this pathway has been implicated in depression [3]. We previously reported that rewardinduced dopamine release in the NAc was suppressed in rats exposed to chronic mild stress (CMS) model [4], a widely used animal model of depression [5]. Dysfunction of the mesolimbic dopaminergic pathway has also been implicated in chronic pain. We demonstrated that reward-induced dopamine release in the NAc [6] an
Data Loading...
