Swadlow H A, Gusev A G
Department of Psychology, The University of Connecticut, 406 Babbidge Road, Storrs, Connecticut 06269, USA.
Nat Neurosci. 2001 Apr;4(4):402-8. doi: 10.1038/86054.
Considerable effort has gone into understanding the mechanisms underlying high-frequency 'bursting' of thalamocortical impulses, their sensory information content and their involvement in perception. However, little is known about the influence of such impulses on their cortical targets. Here we follow bursting thalamic impulses to their terminus at the thalamocortical synapse of the awake rabbit, and examine their influence on a class of somatosensory cortical neurons. We show that thalamic bursts potently activate cortical circuits. Initial impulses of each burst have a greatly enhanced ability to elicit cortical action potentials, and later impulses in the burst further raise the probability of eliciting spikes. In some cases, multiple cortical spikes result from a single burst. Moreover, we show that the interval preceding each burst is crucial for generating the enhanced cortical response. The powerful activation of neocortex by thalamocortical bursts is fully consistent with an involvement of these impulses in perceptual/attentional processes.
人们已经付出了相当大的努力来理解丘脑皮质冲动高频“爆发”的潜在机制、它们的感觉信息内容以及它们在感知中的作用。然而，对于此类冲动对其皮质靶点的影响却知之甚少。在这里，我们追踪清醒兔丘脑皮质突触处爆发性丘脑冲动的终点，并研究它们对一类体感皮质神经元的影响。我们发现丘脑爆发有力地激活了皮质回路。每次爆发的初始冲动引发皮质动作电位的能力大大增强，并且爆发中的后续冲动进一步提高了引发尖峰的概率。在某些情况下，单次爆发会导致多个皮质尖峰。此外，我们表明每次爆发之前的间隔对于产生增强的皮质反应至关重要。丘脑皮质爆发对新皮质的有力激活与这些冲动参与感知/注意力过程完全一致。
