Analysis of synaptic connection specific plasticity following whisker deprivation using laser photostimulation.

在小鼠躯体感觉桶皮质中，我们发现丘脑对GABA能神经元的潜伏期比对兴奋性神经元的潜伏期短，约为0。8毫秒。这种潜伏期的差异使L4和L2/3神经元能够非常快地受到抑制，这在对胡须刺激的反应中产生“L4后L2/3”的尖峰序列起着关键作用。我们还发现，这种潜伏期差异是在P12-14之后产生的，与临界期的启动同步。我们指出，这种潜伏期的差异是由于投射这些靶神经元的轴突厚度的不同所致。

In the somatosensory barrel cortex of mice, we found that thalamic latency to GABAergic neurons are shorter than that to excitatory neurons in layer 4, by about 0. 8 ms. This latency difference enables very fast inhibition in L4 and L2/ 3 neurons, which plays a critical role in generation of spike sequences of" L4 followed by L2/ 3" in response to whisker stimulation. We also found that such latency difference was created after P12-14, simultaneously with the initiation of critical period. We indicated that such latency difference was resulted from differed thickness of axons projecting those target neurons.