Celikel Tansu, Szostak Vanessa A, Feldman Daniel E
Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
Nat Neurosci. 2004 May;7(5):534-41. doi: 10.1038/nn1222. Epub 2004 Apr 4.
Deprivation-induced plasticity of sensory cortical maps involves long-term potentiation (LTP) and depression (LTD) of cortical synapses, but how sensory deprivation triggers LTP and LTD in vivo is unknown. Here we tested whether spike timing-dependent forms of LTP and LTD are involved in this process. We measured spike trains from neurons in layer 4 (L4) and layers 2 and 3 (L2/3) of rat somatosensory cortex before and after acute whisker deprivation, a manipulation that induces whisker map plasticity involving LTD at L4-to-L2/3 (L4-L2/3) synapses. Whisker deprivation caused an immediate reversal of firing order for most L4 and L2/3 neurons and a substantial decorrelation of spike trains, changes known to drive timing-dependent LTD at L4-L2/3 synapses in vitro. In contrast, spike rate changed only modestly. Thus, whisker deprivation is likely to drive map plasticity by spike timing-dependent mechanisms.
感觉皮层图谱的剥夺诱导可塑性涉及皮层突触的长时程增强（LTP）和长时程抑制（LTD），但感觉剥夺如何在体内触发LTP和LTD尚不清楚。在这里，我们测试了LTP和LTD的尖峰时间依赖性形式是否参与了这一过程。我们在急性触须剥夺前后测量了大鼠体感皮层第4层（L4）以及第2和第3层（L2/3）神经元的尖峰序列，急性触须剥夺是一种诱导触须图谱可塑性的操作，该可塑性涉及L4到L2/3（L4-L2/3）突触处的LTD。触须剥夺导致大多数L4和L2/3神经元的放电顺序立即反转，并且尖峰序列出现显著去相关，已知这些变化会在体外驱动L4-L2/3突触处的时间依赖性LTD。相比之下，放电率仅略有变化。因此，触须剥夺可能通过尖峰时间依赖性机制驱动图谱可塑性。
