Endocannabinoid sex differences are present in the rat hippocampus. Specifically, at perisomatic GABAergic synapses, tonic anandamide (AEA) and estrogenic-AEA signaling are active in females but not males. Furthermore, in males, hippocampal eCB function varies along the CA1 pyramidal somatodendritic axis. Constitutive CB1 and tonic 2-AG activity are present at perisomatic GABAergic synapses and lacking at dendritic GABAergic synapses. It is unknown if these eCB somatodendritic differences occur at female GABAergic synapses. Moreover, it is unclear whether eCB sex differences occur at hippocampal glutamatergic synapses. In vitro, field potential (fEPSP) recordings were performed to assess eCB sex differences at rat CA3-CA1 dendritic synapses. At female GABAergic synapses, we observed: 1) constitutive CB1 function, 2) tonic AEA, 3) tonic 2-AG and 3) estrogen (ER_α)-driven 2-AG activity. In contrast, only constitutive CB1 and tonic 2-AG activity was observed in males. Sex differences in eCB/CB1 signaling at dendritic synapses appear to shift the basal excitatory/inhibitory balance towards excitation in females and towards inhibition in males. Chronic Mild Stress (CMS) exposure (21 days) in female rats reverses CB1constitutive function and impairs both tonic and ER_α-driven eCB signaling. Endocannabinoid sex differences under both normal and stress conditions may contribute to sexual disparities in stress-related neurobehavioral disorders.

内源性大麻素的性别差异存在于大鼠海马中。具体来说，在异型GABA能突触中，雌性而非雌性具有强直性阿南酰胺（AEA）和雌激素性AEA信号传导。此外，在男性中，海马eCB功能沿CA1锥体体树突状轴变化。本构CB1和补品2-AG活性存在于过适的GABA能突触中，而缺乏于树突状的GABA能突触中。这些eCB的树突状差异是否发生在雌性GABA能突触上尚不清楚。此外，目前尚不清楚在海马谷氨酸能突触中是否发生eCB性别差异。在体外，进行场电位（fEPSP）记录以评估大鼠CA3-CA1树突突触处的eCB性别差异。在女性的GABA能突触中，我们观察到：1）组成型CB1功能，2）补品AEA，_α）驱动的2-AG活性。相反，在男性中仅观察到组成型CB1和强直2-AG活性。树突触突触中eCB / CB1信号的性别差异似乎使基础兴奋/抑制平衡向雌性兴奋转变，而向雄性抑制转变。慢性轻度应激（CMS）曝光（21天）的雌性大鼠逆转CB1constitutive功能，损害双方的滋补和ER _α驱动的欧洲央行信号。正常和压力条件下的内源性大麻素性别差异可能会导致与压力相关的神经行为障碍的性别差异。