Velasquez Kenia M, Molfese David L, Salas Ramiro
Department of Psychiatry, Baylor College of Medicine Houston, TX, USA.
Front Hum Neurosci. 2014 Mar 28;8:174. doi: 10.3389/fnhum.2014.00174. eCollection 2014.
Interest in the habenula has greatly increased in recent years. The habenula is a small brain structure located posterior to the thalamus and adjacent to the third ventricle. Despite its small size, the habenula can be divided into medial habenula (MHb) and lateral habenula (LHb) nuclei that are anatomically and transcriptionally distinct. The habenula receives inputs from the limbic system and basal ganglia primarily via the stria medullaris. The fasciculus retroflexus is the primary habenular output from the habenula to the midbrain and governs release of glutamate onto gabaergic cells in the rostromedial tegmental nucleus (RMTg) and onto the interpeduncular nucleus. The resulting GABA released from RMTg neurons inactivates dopaminergic cells in the ventral tegmental area/substantia nigra compacta. Through this process, the habenula controls dopamine levels in the striatum. Thus, the habenula plays a critical role in reward and reward-associated learning. The LHb also modulates serotonin levels and norepinephrine release, while the MHb modulates acetylcholine. The habenula is a critical crossroad that influences the brain's response to pain, stress, anxiety, sleep, and reward. Dysfunction of the habenula has been linked to depression, schizophrenia, and the effects of drugs of abuse. This review focuses on the possible relationships between the habenula and drug abuse.
近年来，对缰核的关注大幅增加。缰核是位于丘脑后方且毗邻第三脑室的一个小的脑结构。尽管其体积小，但缰核可分为内侧缰核（MHb）和外侧缰核（LHb）核，它们在解剖学和转录方面都有所不同。缰核主要通过髓纹从边缘系统和基底神经节接收输入。后屈束是缰核从中脑的主要输出，控制谷氨酸释放到嘴内侧被盖核（RMTg）的γ-氨基丁酸能细胞以及脚间核上。RMTg神经元释放的γ-氨基丁酸会使腹侧被盖区/黑质致密部的多巴胺能细胞失活。通过这一过程，缰核控制纹状体中的多巴胺水平。因此，缰核在奖赏及与奖赏相关的学习中起着关键作用。外侧缰核还调节血清素水平和去甲肾上腺素释放，而内侧缰核调节乙酰胆碱。缰核是一个关键的交叉点，影响大脑对疼痛、压力、焦虑、睡眠和奖赏的反应。缰核功能障碍与抑郁症、精神分裂症以及药物滥用的影响有关。本综述重点关注缰核与药物滥用之间的可能关系。
