Short-term fasting decreases excitatory synaptic inputs to ventromedial tuberoinfundibular dopaminergic neurons and attenuates their activity in male mice

NEUROSCIENCE LETTERS

卷:671

Article

Kubota, Takafumi¹  Fukushima, Atsushi¹  Hagiwara, Hiroko¹  Kamiya, Yoshinori²  Furuta, Miyako¹  Miyazaki, Tomoyuki³  Fujioka, Hitomi¹  Fujiwara, Sei-Etsu¹  Funabashi, Toshiya¹  Akema, Tatsuo¹ 

[1] St Marianna Univ, Sch Med, Dept Physiol, Miyamae Ku, 2-16-1 Sugao, Kawasaki, Kanagawa 2168511, Japan

[2] Niigata Univ, Grad Sch Med & Dent Sci, Div Anesthesiol, Chuo Ku, 1-757 Asahimachi, Niigata 9508510, Japan

[3] Yokohama City Univ, Grad Sch Med, Dept Physiol, Kanazawa Ku, 3-9 Fukuura, Yokohama, Kanagawa 2360004, Japan

关键词: TIDA;    PRL;    Miniature excitatory postsynaptic current;    Patch clamp;    Slice;    cFos;    Mediobasal hypothalamus;    Fasting;   

DOI  :  10.1016/j.neulet.2018.02.017

来源: Elsevier

【 摘 要 】

Tuberoinfundibular dopaminergic (TIDA) neurons in the arcuate nucleus (ARC) of the hypothalamus play a role in inhibiting prolactin (PRL) secretion from the anterior pituitary. PRL is involved in a variety of behaviors, including feeding. Consequently, we hypothesized that fasting might reduce the activity of TIDA neurons, which might alter PRL secretion. However, direct examinations of TIDA neuron activity are difficult. Recently, transgenic mice were generated that expressed green fluorescent protein (GFP) under the control of the rat tyrosine hydroxylase gene. We first determined that GFP in the dorsomedial ARC was a reliable marker of TIDA neurons. Then, we performed electrophysiology and immunocytochemistry in GFP-labeled TIDA neurons to examine whether different feeding conditions could change their activity. Eight-week-old male mice were fed or fasted for 24 h. After sacrifice, we prepared acutely isolated brain slices for conducting whole-cell voltage-clamp recordings. TIDA neurons were identified with fluorescence microscopy. The mean amplitude of miniature excitatory postsynaptic currents (mEPSCs) was significantly reduced in fasting mice compared to fed mice, but different feeding conditions did not affect the mean mEPSC intervals. This result suggested that fasting reduced the number of excitatory synaptic inputs to TIDA neurons. To determine whether a reduction in excitatory synaptic inputs would cause a reduction in TIDA neuron activity, we examined the effect of 24-h fasting on c-Fos expression in the ARC. We found that fasting significantly reduced the number of Fos-positive TIDA neurons. In addition, serum PRL levels were significantly increased. Taken together, the present findings suggested that short-term fasting attenuated TIDA neuron activity.

【 授权许可】

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