University of Miami Rosenstiel School of Marine and Atmospheric Science, Division of Marine Biology and Fisheries, Miami, FL 33149, USA.
Comp Biochem Physiol C Toxicol Pharmacol. 2012 Jan;155(1):151-9. doi: 10.1016/j.cbpc.2011.04.001. Epub 2011 Apr 9.
The non-L-glutamate (L-Glu) receptor component of D-aspartate (D-Asp) currents in Aplysia californica buccal S cluster (BSC) neurons was studied with whole cell voltage clamp to differentiate it from receptors activated by other well-known agonists of the Aplysia nervous system and investigate modulatory mechanisms of D-Asp currents associated with synaptic plasticity. Acetylcholine (ACh) and serotonin (5-HT) activated whole cell excitatory currents with similar current voltage relationships to D-Asp. These currents, however, were pharmacologically distinct from D-Asp. ACh currents were blocked by hexamethonium (C6) and tubocurarine (D-TC), while D-Asp currents were unaffected. 5-HT currents were blocked by granisetron and methysergide (MES), while D-Asp currents were unaffected. Conversely, while (2S,3R)-1-(Phenanthren-2-carbonyl)piperazine-2,3-dicarboxylic acid(PPDA) blocked D-Asp currents, it had no effect on ACh or 5-HT currents. Comparison of the charge area described by currents induced by ACh or 5-HT separately from, or with, D-Asp suggests activation of distinct receptors by all 3 agonists. Charge area comparisons with L-Glu, however, suggested some overlap between L-Glu and D-Asp receptors. Ten minute exposure to 5-HT induced facilitation of D-Asp-evoked responses in BSC neurons. This effect was mimicked by phorbol ester, suggesting that protein kinase C (PKC) was involved.
用全细胞膜片钳技术研究了加利福尼亚海兔口腔 S 簇（BSC）神经元中 D-天冬氨酸（D-Asp）电流的非 L-谷氨酸（L-Glu）受体成分，以将其与神经系统中其他广为人知的 Aplysia 激动剂激活的受体区分开来，并研究与突触可塑性相关的 D-Asp 电流的调节机制。乙酰胆碱（ACh）和 5-羟色胺（5-HT）激活的全细胞兴奋性电流与 D-Asp 具有相似的电流-电压关系。然而，这些电流在药理学上与 D-Asp 不同。ACh 电流被六烃季铵（C6）和筒箭毒碱（D-TC）阻断，而 D-Asp 电流不受影响。5-HT 电流被 granisetron 和 methysergide（MES）阻断，而 D-Asp 电流不受影响。相反，虽然（2S,3R）-1-（菲-2-羰基）哌嗪-2,3-二羧酸（PPDA）阻断了 D-Asp 电流，但它对 ACh 或 5-HT 电流没有影响。分别用 ACh 或 5-HT 或与 D-Asp 一起诱导的电流的电荷量面积的比较表明，所有 3 种激动剂都激活了不同的受体。然而，与 L-Glu 的电荷量面积比较表明，L-Glu 和 D-Asp 受体之间存在一些重叠。10 分钟暴露于 5-HT 可增强 BSC 神经元中 D-Asp 诱发反应的易化作用。佛波酯模拟了这种效应，表明蛋白激酶 C（PKC）参与其中。
