Terral Geoffrey, Varilh Marjorie, Cannich Astrid, Massa Federico, Ferreira Guillaume, Marsicano Giovanni
INSERM, U1215 NeuroCentre Magendie, 146 rue Léo Saignat, 33077 Bordeaux Cedex, France; University of Bordeaux, 146 rue Léo Saignat, 33000 Bordeaux, France.
University of Bordeaux, 146 rue Léo Saignat, 33000 Bordeaux, France; INRAE, Bordeaux INP, Nutrition and Integrative Neurobiology, UMR 1286, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France.
Neuroscience. 2020 May 1;433:121-131. doi: 10.1016/j.neuroscience.2020.03.002. Epub 2020 Mar 12.
In the olfactory system, the endocannabinoid system (ECS) regulates sensory perception and memory. A major structure involved in these processes is the anterior piriform cortex (aPC), but the impact of ECS signaling in aPC circuitry is still scantly characterized. Using ex vivo patch clamp experiments in mice and neuroanatomical approaches, we show that the two major forms of ECS-dependent synaptic plasticity, namely depolarization-dependent suppression of inhibition (DSI) and long-term depression of inhibitory transmission (iLTD) are present in the aPC. Interestingly, iLTD expression depends on layer localization of the inhibitory neurons associated with the expression of the neuropeptide cholecystokinin. Conversely, the decrease of inhibitory transmission induced by exogenous cannabinoid agonists or DSI do not seem to be impacted by these factors. Altogether, these results indicate that CB1 receptors exert an anatomically specific and differential control of inhibitory plasticity in the aPC, likely involved in spatiotemporal regulation of olfactory processes.
在嗅觉系统中，内源性大麻素系统（ECS）调节感觉知觉和记忆。参与这些过程的一个主要结构是前梨状皮质（aPC），但ECS信号在aPC神经回路中的影响仍鲜为人知。通过在小鼠中进行的离体膜片钳实验和神经解剖学方法，我们发现ECS依赖的两种主要形式的突触可塑性，即去极化依赖性抑制抑制（DSI）和抑制性传递的长期抑制（iLTD）存在于aPC中。有趣的是，iLTD的表达取决于与神经肽胆囊收缩素表达相关的抑制性神经元的层定位。相反，外源性大麻素激动剂或DSI诱导的抑制性传递减少似乎不受这些因素的影响。总之，这些结果表明CB1受体对aPC中的抑制性可塑性发挥解剖学上特定的和差异性的控制，这可能参与嗅觉过程的时空调节。
