Two-photon imaging of D1 and D2 type neurons in the olfactory tubercle of behaving mice

Positive and negative associations acquired through olfactory experience are thought to be especially strong and long-lasting. The conserved direct olfactory sensory input to the ventral striatal olfactory tubercle (OT) and its convergence with dense dopaminergic input to the OT could underlie this privileged form of associative memory, but how this process occurs is not well understood. We imaged the activity of the two canonical types of striatal neurons, expressing D1 or D2 type dopamine receptors, in the OT at cellular resolution while mice learned odor-outcome associations ranging from aversive to rewarding. D1 and D2 neurons both responded to rewarding and aversive odors. D1 neurons in the OT robustly and bidirectionally represented odor valence, responding similarly to odors predicting similar outcomes regardless of odor identity. This valence representation persisted even in the absence of an instrumental response to the odors and in the absence of the outcomes, indicating a tru...人们认为，通过嗅觉经验所形成的正负性联想尤为强烈且持久。投射至腹侧纹状体嗅结节（olfactory tubercle, OT）的保守直接嗅觉感官输入，以及该输入与密集多巴胺能输入在OT内的汇聚，可能是这种特殊联想记忆的生物学基础，但该过程的具体机制尚未明确。本研究在小鼠学习从厌恶性到奖赏性的气味-结果关联任务时，以单细胞分辨率对嗅结节内两类经典纹状体神经元——表达D1型或D2型多巴胺受体的神经元——的活动进行了成像。实验结果显示，嗅结节内的D1与D2神经元均可响应奖赏性与厌恶性气味。其中，D1神经元能够稳健且双向地编码气味效价：无论气味的种类如何，其对预测同类结果的气味均会产生相似的响应。即使在小鼠无需对气味做出工具性反应、且无结果呈现的情境下，这种气味效价表征依然存在，表明一种真正的……