Recruitment of GABAergic Interneurons in the Barrel Cortex during Active Tactile Behavior

Cell type-specific recordings from fast-spiking (PV expressing), Sst, VIP neurons in the barrel cortex during active tactile behavior<br>Neural computation involves diverse types of GABAergic inhibitory interneurons that are integrated with excitatory (E) neurons into precisely structured circuits. To understand how each neuron type shapes sensory representations, we measured firing patterns of defined types of neurons in the barrel cortex while mice performed an active, whisker-dependent object localization task. Touch excited fast-spiking (FS) interneurons at short latency, followed by activation of E neurons and somatostatin-expressing (SST) interneurons. Touch only weakly modulated vasoactive intestinal polypeptide-expressing (VIP) interneurons. Voluntary whisker movement activated FS neurons in the ventral posteromedial nucleus (VPM) target layers, a subset of SST neurons and a majority of VIP neurons. Together, FS neurons track thalamic input, mediating feedforward inhibition. SST neurons monitor local excitation, providing feedback inhibition. VIP neurons are activated by non-sensory inputs, disinhibiting E and FS neurons. Our data reveal rules of recruitment for interneuron types during behavior, providing foundations for understanding computation in cortical microcircuits.<br>

Cell type-specific recordings from fast-spiking (PV expressing), Sst, VIP neurons in the barrel cortex during active tactile behavior<br>神经计算涉及多种γ-氨基丁酸能抑制性中间神经元，它们与兴奋性（E）神经元整合形成精确的结构化回路。为理解每种神经元类型如何塑造感觉表征，我们在小鼠执行主动、依赖胡须的物体定位任务时，测量了桶状皮层中特定类型神经元的放电模式。触觉刺激能在短潜伏期内兴奋快棘波（FS）中间神经元，随后激活E神经元及表达生长抑素（SST）的中间神经元。触觉对表达血管活性肠肽（VIP）的中间神经元仅产生微弱调制作用。<br>自主胡须运动可激活腹后内侧核（VPM）靶层中的FS神经元、部分SST神经元及大部分VIP神经元。综上，FS神经元追踪丘脑输入，介导前馈抑制；SST神经元监测局部兴奋，提供反馈抑制；VIP神经元由非感觉输入激活，对E神经元及FS神经元产生去抑制作用。我们的数据揭示了行为过程中不同类型中间神经元的募集规则，为理解皮层微回路中的计算机制奠定了基础。<br>