Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche-Consejo Superior de Investigaciones Científicas, Campus de San Juan, 03550 Sant Joan d'Alacant, Spain, and INSERM U901, Institut de Neurobiologie de la Méditerranée, 13273 Marseille, France.
J Neurosci. 2014 Jan 8;34(2):515-26. doi: 10.1523/JNEUROSCI.2441-13.2014.
To produce sensation, neuronal pathways must transmit and process stimulus patterns that unfold over time. This behavior is determined by short-term synaptic plasticity (STP), which shapes the temporal filtering properties of synapses in a pathway. We explored STP variability across thalamocortical (TC) synapses, measuring whole-cell responses to stimulation of TC fibers in layer 4 neurons of mouse barrel cortex in vitro. As expected, STP during stimulation from rest was dominated by depression. However, STP during ongoing stimulation was strikingly diverse across TC connections. Diversity took the form of variable tuning to the latest interstimulus interval: some connections responded weakly to shorter intervals, while other connections were facilitated. These behaviors did not cluster into categories but formed a continuum. Diverse tuning did not require disynaptic inhibition. Hence, monosynaptic excitatory lemniscal TC connections onto layer 4 do not behave uniformly during ongoing stimulation. Each connection responds differentially to particular stimulation intervals, enriching the ability of the pathway to convey complex, temporally fluctuating information.
为了产生感觉，神经元通路必须传输和处理随时间展开的刺激模式。这种行为由短期突触可塑性（STP）决定，它塑造了通路中突触的时间滤波特性。我们在体外研究了皮层丘脑（TC）突触的 STP 变异性，测量了对来自小鼠桶状皮层第 4 层神经元的 TC 纤维刺激的全细胞反应。正如预期的那样，来自休息状态的刺激期间的 STP 主要表现为抑制。然而，在持续刺激期间，TC 连接之间的 STP 明显多种多样。多样性表现为对最新的刺激间间隔的可变调谐：一些连接对较短的间隔反应较弱，而其他连接则得到促进。这些行为没有聚类成类别，而是形成了一个连续体。不同的调谐不需要双突触抑制。因此，在持续刺激期间，单突触兴奋性薄束 TC 连接到第 4 层的行为并不统一。每个连接对特定的刺激间隔有不同的反应，从而丰富了通路传递复杂、随时间波动的信息的能力。
