TY - JOUR T1 - Serotonergic Suppression of Mouse Prefrontal Circuits Implicated in Task Attention JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0269-16.2016 VL - 3 IS - 5 SP - ENEURO.0269-16.2016 AU - Michael K. Tian AU - Eric F. Schmidt AU - Evelyn K. Lambe Y1 - 2016/09/01 UR - http://www.eneuro.org/content/3/5/ENEURO.0269-16.2016.abstract N2 - Serotonin (5-HT) regulates attention by neurobiological mechanisms that are not well understood. Layer 6 (L6) pyramidal neurons of prefrontal cortex play an important role in attention and express 5-HT receptors, but the serotonergic modulation of this layer and its excitatory output is not known. Here, we performed whole-cell recordings and pharmacological manipulations in acute brain slices from wild-type and transgenic mice expressing either eGFP or eGFP-channelrhodopsin in prefrontal L6 pyramidal neurons. Excitatory circuits between L6 pyramidal neurons and L5 GABAergic interneurons, including a population of interneurons essential for task attention, were investigated using optogenetic techniques. Our experiments show that prefrontal L6 pyramidal neurons are subject to strong serotonergic inhibition and demonstrate direct 5-HT–sensitive connections between prefrontal L6 pyramidal neurons and two classes of L5 interneurons. This work helps to build a neurobiological framework to appreciate serotonergic disruption of task attention and yields insight into the disruptions of attention observed in psychiatric disorders with altered 5-HT receptors and signaling. ER -