Horvitz Jon C
Program in Cognitive Neuroscience, Department of Psychology, The City College of the City University of New York, 138th Street and Convent Avenue, New York, NY 10031, United States.
Behav Brain Res. 2009 Apr 12;199(1):129-40. doi: 10.1016/j.bbr.2008.12.014. Epub 2008 Dec 14.
While midbrain DA neurons show phasic activations in response to both reward-predicting and salient non-reward events, activation responses to primary and conditioned rewards are sustained for several hundreds of milliseconds beyond those elicited by salient non-reward-related stimuli. The longer-duration DA reward response and corresponding elevated DA release in striatal target sites may selectively strengthen currently-active corticostriatal synapses, i.e., those associated with the successful reward-procuring behavior. This paper describes how similar models of DA-mediated plasticity of corticostriatal synapses may describe both stimulus-response and response-outcome learning. DA-mediated strengthening of corticostriatal synapses in regions of the dorsolateral striatum receiving afferents from primary sensorimotor cortex is likely to bind corticostriatal inputs representing the previously-emitted movement to striatal outputs contributing to the selection of the next movement segment in a behavioral sequence. Within the striatum, more generally, inputs from distinct regions of the frontal cortex that code independently for movement direction and reward expectation send convergent projections to striatal output cells. DA-mediated strengthening of active corticostriatal synapses promotes the future output of the striatal cell under similar input conditions. This is postulated to promote persistence of neuronal activity in the very cortical cells that drive corticostriatal input, leading to the establishment of sustained reverberatory loops that permit cortical movement-related cells to maintain activity until the appropriate time of movement initiation.
虽然中脑多巴胺能神经元对奖励预测和显著的非奖励事件均表现出相位激活,但对初级奖励和条件性奖励的激活反应会持续数百毫秒,超过由显著的非奖励相关刺激引发的反应。在纹状体靶位点中,持续时间更长的多巴胺奖励反应及相应升高的多巴胺释放可能会选择性地增强当前活跃的皮质纹状体突触,即那些与成功获取奖励行为相关的突触。本文描述了多巴胺介导的皮质纹状体突触可塑性的类似模型如何既能描述刺激-反应学习,又能描述反应-结果学习。多巴胺介导的背外侧纹状体区域皮质纹状体突触增强,该区域接收来自初级感觉运动皮层的传入神经,这可能会将代表先前发出动作的皮质纹状体输入与有助于在行为序列中选择下一个动作片段的纹状体输出联系起来。更一般地说,在纹状体内,额叶皮层不同区域独立编码运动方向和奖励期望的输入会向纹状体输出细胞发送汇聚投射。多巴胺介导对活跃皮质纹状体突触的增强作用会促进在相似输入条件下纹状体细胞的未来输出。据推测,这会促进驱动皮质纹状体输入的皮质细胞中神经元活动的持续,从而导致建立持续的回响回路,使与皮质运动相关的细胞能够维持活动,直到适当的运动启动时间。
Behav Brain Res. 2009-4-12
Behav Brain Res. 2009-4-12
Prog Neurobiol. 2011-6-17
Trends Neurosci. 2007-5
Neural Netw. 2002
Prog Brain Res. 2000
J Neurosci. 2005-12-7
Exp Brain Res. 2009-11-11
Learn Mem. 2020-10
Eur J Neurosci. 2019-11
Front Comput Neurosci. 2017-3-7
Science. 2008-8-8
Annu Rev Neurosci. 2008
J Neurosci. 2007-12-26
Brain Res Rev. 2008-8
Trends Cogn Sci. 2007-11