Johansson Fredrik, Jirenhed Dan-Anders, Rasmussen Anders, Zucca Riccardo, Hesslow Germund
Associative Learning Group, Department of Experimental Medical Science, Lund University, S-221 84 Lund, Sweden; The Linnaeus Center Thinking in Time: Cognition, Communication and Learning, Lund University, S-222 00 Lund, Sweden; and
Associative Learning Group, Department of Experimental Medical Science, Lund University, S-221 84 Lund, Sweden; The Linnaeus Center Thinking in Time: Cognition, Communication and Learning, Lund University, S-222 00 Lund, Sweden; and.
Proc Natl Acad Sci U S A. 2014 Oct 14;111(41):14930-4. doi: 10.1073/pnas.1415371111. Epub 2014 Sep 29.
The standard view of the mechanisms underlying learning is that they involve strengthening or weakening synaptic connections. Learned response timing is thought to combine such plasticity with temporally patterned inputs to the neuron. We show here that a cerebellar Purkinje cell in a ferret can learn to respond to a specific input with a temporal pattern of activity consisting of temporally specific increases and decreases in firing over hundreds of milliseconds without a temporally patterned input. Training Purkinje cells with direct stimulation of immediate afferents, the parallel fibers, and pharmacological blocking of interneurons shows that the timing mechanism is intrinsic to the cell itself. Purkinje cells can learn to respond not only with increased or decreased firing but also with an adaptively timed activity pattern.
关于学习背后机制的标准观点是,它们涉及突触连接的增强或减弱。习得的反应时间被认为是将这种可塑性与神经元的时间模式输入相结合。我们在此表明,雪貂的小脑浦肯野细胞可以在没有时间模式输入的情况下,学会以一种活动的时间模式对特定输入做出反应,这种活动模式包括在数百毫秒内放电的时间特异性增加和减少。通过直接刺激直接传入纤维(平行纤维)并对中间神经元进行药理学阻断来训练浦肯野细胞,结果表明计时机制是细胞本身所固有的。浦肯野细胞不仅可以学会通过增加或减少放电来做出反应,还可以学会以一种适应性定时的活动模式做出反应。