School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK,
Cogn Neurodyn. 2008 Jun;2(2):159-70. doi: 10.1007/s11571-008-9050-4. Epub 2008 Apr 23.
Gating of sensory information can be assessed using an auditory conditioning-test paradigm which measures the reduction in the auditory evoked response to a test stimulus following an initial conditioning stimulus. Recording brainwaves from specific areas of the brain using multiple electrodes is helpful in the study of the neurobiology of sensory gating. In this paper, we use such technology to investigate the role of cannabinoids in sensory gating in the CA3 region of the rat hippocampus. Our experimental results show that application of the exogenous cannabinoid agonist WIN55,212-2 can abolish sensory gating. We have developed a phenomenological model of cannabinoid dynamics incorporated within a spiking neural network model of CA3 with synaptically interacting pyramidal and basket cells. Direct numerical simulations of this model suggest that the basic mechanism for this effect can be traced to the suppression of inhibition of slow GABA(B) synapses. Furthermore, by working with a simpler mathematical firing rate model we are able to show the robustness of this mechanism for the abolition of sensory gating.
可以使用听觉条件反射测试范式来评估感觉信息的门控，该范式通过测量初始条件刺激后测试刺激的听觉诱发电应对听觉诱发电应的减少来评估感觉信息的门控。使用多个电极记录大脑特定区域的脑电波有助于研究感觉门控的神经生物学。在本文中，我们使用这种技术来研究大麻素在大鼠海马 CA3 区感觉门控中的作用。我们的实验结果表明，外源性大麻素激动剂 WIN55,212-2 的应用可以消除感觉门控。我们已经开发了一种包含 CA3 中具有突触相互作用的锥体和篮状细胞的尖峰神经网络模型的大麻素动力学现象学模型。该模型的直接数值模拟表明，这种效应的基本机制可以追溯到对慢 GABA（B）突触抑制的抑制。此外，通过使用更简单的数学发放率模型，我们能够证明这种消除感觉门控的机制的稳健性。
