Klenowski Paul M, Shariff Masroor R, Belmer Arnauld, Fogarty Matthew J, Mu Erica W H, Bellingham Mark C, Bartlett Selena E
Translational Research Institute and Institute for Health and Biomedical Innovation, Queensland University of Technology Brisbane, QLD, Australia.
School of Biomedical Sciences, The University of Queensland Brisbane, QLD, Australia.
Front Behav Neurosci. 2016 Mar 23;10:54. doi: 10.3389/fnbeh.2016.00054. eCollection 2016.
The modern diet has become highly sweetened, resulting in unprecedented levels of sugar consumption, particularly among adolescents. While chronic long-term sugar intake is known to contribute to the development of metabolic disorders including obesity and type II diabetes, little is known regarding the direct consequences of long-term, binge-like sugar consumption on the brain. Because sugar can cause the release of dopamine in the nucleus accumbens (NAc) similarly to drugs of abuse, we investigated changes in the morphology of neurons in this brain region following short- (4 weeks) and long-term (12 weeks) binge-like sucrose consumption using an intermittent two-bottle choice paradigm. We used Golgi-Cox staining to impregnate medium spiny neurons (MSNs) from the NAc core and shell of short- and long-term sucrose consuming rats and compared these to age-matched water controls. We show that prolonged binge-like sucrose consumption significantly decreased the total dendritic length of NAc shell MSNs compared to age-matched control rats. We also found that the restructuring of these neurons resulted primarily from reduced distal dendritic complexity. Conversely, we observed increased spine densities at the distal branch orders of NAc shell MSNs from long-term sucrose consuming rats. Combined, these results highlight the neuronal effects of prolonged binge-like intake of sucrose on NAc shell MSN morphology.
现代饮食中的糖分含量已变得极高，导致糖的摄入量达到了前所未有的水平，尤其是在青少年群体中。虽然长期慢性摄入糖分会导致包括肥胖症和II型糖尿病在内的代谢紊乱，但长期、类似暴饮暴食的糖摄入对大脑的直接影响却鲜为人知。由于糖与滥用药物类似，能够引起伏隔核（NAc）中多巴胺的释放，我们使用间歇性双瓶选择范式，研究了短期（4周）和长期（12周）类似暴饮暴食的蔗糖摄入后，该脑区神经元形态的变化。我们使用高尔基-考克斯染色法，浸染短期和长期摄入蔗糖的大鼠伏隔核核心和壳中的中等棘状神经元（MSN），并将其与年龄匹配的饮水对照组进行比较。我们发现，与年龄匹配的对照大鼠相比，长期类似暴饮暴食的蔗糖摄入显著降低了伏隔核壳MSN的总树突长度。我们还发现，这些神经元的结构重组主要源于远端树突复杂性的降低。相反，我们观察到长期摄入蔗糖的大鼠伏隔核壳MSN远端分支处的棘密度增加。综合来看，这些结果凸显了长期类似暴饮暴食的蔗糖摄入对伏隔核壳MSN形态的神经元影响。
