Department of Behavioral Neuroscience.
Janos Szentagothai School of Neurosciences, Semmelweis University, 1085, Budapest, Hungary, and.
J Neurosci. 2018 Apr 25;38(17):4065-4075. doi: 10.1523/JNEUROSCI.3234-17.2018. Epub 2018 Feb 27.
An important question in behavioral neurobiology is how particular neuron populations and pathways mediate the overall roles of brain structures. Here we investigated this issue by studying the medial prefrontal cortex (mPFC), an established locus of inhibitory control of aggression. We established in male rats that dominantly distinct mPFC neuron populations project to and produce dense fiber networks with glutamate release sites in the mediobasal hypothalamus (MBH) and lateral hypothalamus (LH; i.e., two executory centers of species-specific and violent bites, respectively). Optogenetic stimulation of mPFC terminals in MBH distinctively increased bite counts in resident/intruder conflicts, whereas the stimulation of similar terminals in LH specifically resulted in violent bites. No other behaviors were affected by stimulations. These findings show that the mPFC controls aggressiveness by behaviorally dedicated neuron populations and pathways, the roles of which may be opposite to those observed in experiments where the role of the whole mPFC (or of its major parts) has been investigated. Overall, our findings suggest that the mPFC organizes into working units that fulfill specific aspects of its wide-ranging roles. Aggression control is associated with many cognitive and emotional aspects processed by the prefrontal cortex (PFC). However, how the prefrontal cortex influences quantitative and qualitative aspects of aggressive behavior remains unclear. We demonstrated that dominantly distinct PFC neuron populations project to the mediobasal hypothalamus (MBH) and the lateral hypothalamus (LH; i.e., two executory centers of species-specific and violent bites, respectively). Stimulation of mPFC fibers in MBH distinctively increased bite counts during fighting, whereas stimulation of similar terminals in LH specifically resulted in violent bites. Overall, our results suggest a direct prefrontal control over the hypothalamus, which is involved in the modulation of quantitative and qualitative aspects of aggressive behavior through distinct prefrontohypothalamic projections.
行为神经生物学中的一个重要问题是，特定的神经元群体和通路如何介导大脑结构的整体作用。在这里，我们通过研究内侧前额叶皮层（mPFC）来研究这个问题，mPFC 是抑制攻击性的一个既定部位。我们在雄性大鼠中确定，支配性不同的 mPFC 神经元群体投射到并产生密集的纤维网络，其中包含谷氨酸释放位点，位于中脑基底部下丘脑（MBH）和外侧下丘脑（LH）；即，分别是物种特异性和暴力咬伤的两个执行中心。光遗传学刺激 MBH 中的 mPFC 末梢会显著增加居住者/入侵者冲突中的咬伤次数，而刺激 LH 中类似的末梢则会导致暴力咬伤。刺激不会影响其他行为。这些发现表明，mPFC 通过行为特化的神经元群体和通路控制攻击性，其作用可能与整个 mPFC（或其主要部分）的作用相反。总体而言，我们的发现表明，mPFC 组织成执行特定功能的工作单元，这些功能可能与前额叶皮层（PFC）处理的许多认知和情感方面有关。然而，前额叶皮层如何影响攻击性行为的定量和定性方面仍不清楚。我们证明，支配性不同的 PFC 神经元群体投射到中脑基底部下丘脑（MBH）和外侧下丘脑（LH）；即，分别是物种特异性和暴力咬伤的两个执行中心。刺激 MBH 中的 mPFC 纤维会显著增加战斗中的咬伤次数，而刺激 LH 中的类似末梢则会导致暴力咬伤。总体而言，我们的结果表明，前额叶皮层对下丘脑有直接的控制作用，通过不同的prefrontohypothalamic 投射，涉及到攻击性行为的定量和定性方面的调节。
