Roberts L A, Large C H, O'Shaughnessy C T, Morris B J
Division of Neuroscience and Biomedical Systems, Institute of Biomedical and Life Sciences, Glasgow University, UK.
Neurosci Lett. 1997 May 23;227(3):205-8. doi: 10.1016/s0304-3940(97)00349-2.
Enkephalin peptides released from hippocampal mossy fibres lower the threshold for the generation of long-term potentiation (LTP) at the mossy fibre synapses. High frequency stimulation of the hippocampal dentate gyrus, sufficient to induce mossy fibre LTP, is associated with increased expression of the proenkephalin gene in the granule cells. We show here that a similar elevation in proenkephalin mRNA levels is observed, in anaesthetised rats, following stimulation of the perforant path sufficient to induce LTP in the perforant path/granule cell synapses. This strengthens the evidence implicating granule cell enkephalins as mediators of functional plasticity in the hippocampus. Furthermore. the results hint at a form of 'domino plasticity', where potentiation of transmission at the perforant path/granule cell synapses is subsequently followed by an enkephalin-mediated potentiation of transmission at the mossy fibre synapses.
从海马苔藓纤维释放的脑啡肽降低了苔藓纤维突触处产生长时程增强（LTP）的阈值。对海马齿状回进行足以诱导苔藓纤维LTP的高频刺激，与颗粒细胞中前脑啡肽基因表达增加有关。我们在此表明，在麻醉大鼠中，刺激穿通通路足以在穿通通路/颗粒细胞突触处诱导LTP后，前脑啡肽mRNA水平也会出现类似升高。这进一步证明颗粒细胞脑啡肽是海马功能可塑性的介导因子。此外，结果还暗示了一种“多米诺可塑性”形式，即穿通通路/颗粒细胞突触处的传递增强之后，随后是脑啡肽介导的苔藓纤维突触处的传递增强。
