Haley Melissa S, Fontanini Alfredo, Maffei Arianna
Department of Neurobiology and Behavior and Program in Neuroscience, State University of New York-Stony Brook, Stony Brook, New York 11794.
Department of Neurobiology and Behavior and Program in Neuroscience, State University of New York-Stony Brook, Stony Brook, New York 11794
J Neurosci. 2016 Mar 2;36(9):2623-37. doi: 10.1523/JNEUROSCI.3224-15.2016.
The primary gustatory cortex (GC) receives projections from the basolateral nucleus of the amygdala (BLA). Behavioral and electrophysiological studies demonstrated that this projection is involved in encoding the hedonic value of taste and is a source of anticipatory activity in GC. Anatomically, this projection is largest in the agranular portion of GC; however, its synaptic targets and synaptic properties are currently unknown. In vivo electrophysiological recordings report conflicting evidence about BLA afferents either selectively activating excitatory neurons or driving a compound response consistent with the activation of inhibitory circuits. Here we demonstrate that BLA afferents directly activate excitatory neurons and two distinct populations of inhibitory neurons in both superficial and deep layers of rat GC. BLA afferents recruit different proportions of excitatory and inhibitory neurons and show distinct patterns of circuit activation in the superficial and deep layers of GC. These results provide the first circuit-level analysis of BLA inputs to a sensory area. Laminar- and target-specific differences of BLA inputs likely explain the complexity of amygdalocortical interactions during sensory processing.
Projections from the basolateral nucleus of the amygdala (BLA) to the cortex convey information about the emotional value and the expectation of a sensory stimulus. Although much work has been done to establish the behavioral role of BLA inputs to sensory cortices, very little is known about the circuit organization of BLA projections. Here we provide the first in-depth analysis of connectivity and synaptic properties of the BLA input to the gustatory cortex. We show that BLA afferents activate excitatory and inhibitory circuits in a layer-specific and pattern-specific manner. Our results provide important new information about how neural circuits establishing the hedonic value of sensory stimuli and driving anticipatory behaviors are organized at the synaptic level.
初级味觉皮层（GC）接收来自杏仁核基底外侧核（BLA）的投射。行为学和电生理学研究表明，这一投射参与对味觉享乐价值的编码，并且是GC中预期活动的一个来源。在解剖学上，这一投射在GC的无颗粒部分最大；然而，其突触靶点和突触特性目前尚不清楚。体内电生理学记录报道了关于BLA传入纤维的相互矛盾的证据，即要么选择性地激活兴奋性神经元，要么驱动与抑制性回路激活一致的复合反应。在这里，我们证明BLA传入纤维直接激活大鼠GC浅层和深层中的兴奋性神经元以及两类不同的抑制性神经元群体。BLA传入纤维募集不同比例的兴奋性和抑制性神经元，并在GC的浅层和深层显示出不同的回路激活模式。这些结果首次对感觉区域的BLA输入进行了回路水平的分析。BLA输入的层特异性和靶点特异性差异可能解释了感觉处理过程中杏仁核-皮层相互作用的复杂性。
从杏仁核基底外侧核（BLA）到皮层的投射传递有关感觉刺激的情感价值和预期的信息。尽管已经做了很多工作来确立BLA输入到感觉皮层的行为作用，但对于BLA投射的回路组织却知之甚少。在这里，我们首次对BLA输入到味觉皮层的连接性和突触特性进行了深入分析。我们表明，BLA传入纤维以层特异性和模式特异性的方式激活兴奋性和抑制性回路。我们的结果提供了关于在突触水平上建立感觉刺激享乐价值并驱动预期行为的神经回路是如何组织的重要新信息。
