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42 Rudd, M.,Vohs, K. D.&Aaker, J.‘Awe expands people’s perception of time, alters decision making and enhances well-being’.Psychological Science ,23,1130-6(2012).
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43 Stetson, Fiesta&Eagleman,2007.
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44 Sergent, C.,Baillet, S.&Dehaene, S.‘Timing of the brain events underlying access to consciousness during the attentional blink’.Nature and Neuroscience ,8,1391-1400(2005);另请参阅Libet, B.Mind Time:The Temporal Factor in Consciousness .(Harvard University Press,2004).
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45 哺乳动物大脑皮层中的突触连接会在50微米到200微米之间的衰变,不会被任何单个刺激的参数差异所影响。Petreanu, L.et al.‘The subcellular organization of neocortical excitatory connections’.Nature ,457,1142-5(2009).Romand, S.et al.‘Morphological development of thick-tufted layer v pyramidal cells in the rat somatosensory cortex’.Frontiers in Neuroanatomy ,5,5(2011).Perin, R.,Berger, T.K.&Markram, H.‘A synaptic organizing principle for cortical neuronal groups’.Proceedings of the National Academy of Sciences of the United States of America ,108,5419-24(2011).Boudkkazi, S.,Fronzaroli-Molinieres, L.&Debanne, D.‘Presynaptic action potential waveform deter-mines cortical synaptic latency’.Journal of Physiology ,589,1117-31(2011).
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46 Chakraborty, S.,Sandberg, A.&Greenfield, S. A.‘Differential dynamics of transient neuronal assemblies in visual compared to auditory cortex’.Experimental Brain Research ,182,491-8(2007).
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47 然而,神经元集合内活动的传播速度很缓慢,有时候需要几百毫秒,这一现象仅仅通过大量突触连接所产生的叠加效应便可以解释,借此,这种神经传递的复杂过程将极大地减低信号的速度。从神经递质被释放出来,进行扩散,直到在其受体处发挥作用大约需要0.75毫秒,这种潜在的冗长时间框架难道还不足以代表成百上千个连续突触连接的总和吗?答案是并不能:即使一个缓慢的兴奋性电位可以先于或源自于传统的突触活动,其时间尺度最大也只能持续20毫秒。这将意味着:在神经元集合中心的原始刺激初始位点很有可能在最初的100毫秒左右就发生了衰减,并且在这之前,神经元集合在其周界上有最大的活动强度:事实上,对立的空间模式始终能够观察到,即最强的活动总是出现在中心。
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48 Hestrin, S.,Sah, P.&Nicoll, R. A.‘Mechanisms generating the time course of dual component excitatory synaptic currents recorded in hippocampal slices’.Neuron ,5,247-53(1990).Salin, P.A.&Prince, D.A.‘Spontaneous GAB-AA receptor-mediated inhibitory currents in adult rat somatosensory cortex’.Journal of Neurophysiology ,75,1573-88(1996).Katz, B.&Miledi, R.‘The measurement of synaptic delay, and the time course of acetylcholine release at the neuromuscular junction’.Proceedings of the Royal Society of London B.Biological Sciences ,161,483-95(1965).Sayer, R.J.,Friedlander, M.J.&Redman, S.J.‘The time course and amplitude of EPSPs evoked at synapses between pairs of CA3/CA1 neurons in the hippocampal slice’.Journal of Neuroscience ,10,826-36(1990).
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49 尽管我们不能完全排除这样一个事实,即皮层内回路的传导速度仅为正常速度的四分之一,但也有证据表明,如果有可能的话,他会提高到正常速度的十倍。Salami, M.et al.‘Change of conduction velocity by regional myelination yields constant latency irrespective of distance between thalamus and cortex’.Proceedings of the National Academy of Sciences of the United States of America ,100,6174-9(2003).
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50 Taber, K. H.&Hurley, R.A.‘Volume transmission in the brain:beyond the synapse’.Journal of Neuropsychiatry and Clinical Neuro-science ,26,iv,1-4(2014);另请参阅Agnati, L.F.et al.‘Information handling by the brain:proposal of a new“paradigm”involving the roamer type of volume transmission and the tunneling nanotube type of wiring transmission’.Journal of Neural Transmission (2014).
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51 Cheramy, A.,Leviel, V.&Glowinski, J.‘Dendritic release of dopamine in the substantia nigra’.Nature ,289,537-42(1981). Greenfield, S.et al.‘In vivo release of acetylcholinesterase in cat substantia nigra and caudate nucleus’.Nature ,284,355-7(1980).Greenfield, S.A.‘The signifcance of dendritic release of transmitter and protein in the substantia nigra’.Neurochemistry International ,7,887-901(1985).Nedergaard, S.,Bolam, J.P.&Greenfield, S.A.‘Facilitation of a dendritic calcium conductance by 5-hydroxytryptamine in the substantia nigra’.Nature ,333,174-7(1988).Chen, B.T.et al.‘Differential calcium dependence of axonal versus somatodendritic dopamine release, with characteristics of both in the ventral tegmental area’.Frontiers in Systems Neuroscience ,5,39(2011).Mercer, L.,del Fiacco, M.&Cuello, A.C.‘The smooth endoplasmic reticulum as a possible storage site for dendritic dopamine in substantia nigra neurones’.Experientia ,35,101-3(1979).
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52 在哺乳动物中,大脑皮层的传导速度在0.1到0.5米/秒之间;也就是说,动作电位沿着轴突(axon)传递的速度是100到500毫米/秒(0.1到0.5毫米/毫秒)。与这一速度一致的是,当刺激从其来源发出后(例如,丘脑,一个突触,间距有2.5毫米),大脑皮层中神经元集合形成的第一个信号出现在5毫秒的时候(图10)。但随后,一旦出现了两个区域之间的突触传递,神经元集合需要额外花费15至20毫秒来达到最大速度,这一速度慢的惊人,以至于突触无法靠其自身进行传递,当然对于被动扩散来说这一速度还是太快了。González-Burgos, G.,Barrionuevo, G.&Lewis, D.A.‘Horizontal synaptic connections in monkey prefrontal cortex:anin vitro elec-trophysiological study’.Cerebral Cortex ,10,82-92(2000).Stuart, G.,Schiller, J.&Sakmann, B.‘Action potential initiation and propagation in rat neocortical pyramidal neurons’.Journal of Physiology ,505(Pt 3)617-32(1997).
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53 两个并列的细胞分别形成一个半通道共同组成了间隙连接,这两个半通道由蛋白质(连接类蛋白)构成。
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54 Draguhn, A. et al.‘Electrical coupling underlies high-frequency oscillations in the hippocampusin vitro ‘.Nature ,394,189-92(1998).
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55 纯粹就“高速的”神经活动而言,200Hz震荡与神经元集合中的信号强度有多大的可比性呢?这一速度的频率意味着动作电位通常每5毫秒产生一次,因此,在一个神经元集合时间窗口中大约有60次动作电位:我们目前的计算能够解释这种活动水平,该活动可以通过电磁机制在荧光信号中,以周期性超极化的形式显现出来,因为自体波(self-substance wave)震荡的快慢没有限制。Huang H.et al.‘Remote control of ion channels and neurones through magnetic-feld heating of nanoparticles’,Nature Nanotechnology ,5,602(2011).Anastassiou C.A.et al.‘The effect of spatially inhomo-geneous extracellular electric fields on neurones’.Journal of Neuroscience ,30,1925(2010).
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56 Masson, G. S.&Ilg, U.W.Dynamics of Visual Motion Processing:Neuronal, Behavioral and Computational Approaches .(Springer,2010).
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57 例如,视网膜中缝隙连接的表达与神经递质多巴胺的可用性成反比,此外人们认为电信号连接和化学突触通常作为一个相互协调的整体共同发挥作用。He, S.,Weiler, R.&Vaney, D.I.‘Endogenous dopaminergic regulation of horizontal cell coupling in the mammalian retina’.Journal of Comparative Neurology ,418,33-40(2000).Pereda, A.E.‘Electrical synapses and their functional interactions with chemical synapses’.Nature Reviews Neuroscience ,15,250-63(2014).
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58 Chakraborty, Sandberg&Greenfield,2007.
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59 Bachmann, T.Microgenetic Approach to the Conscious Mind .(John Benja-mins,2000).
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60 Vogel, E. K.,Luck, S.J.&Shapiro, K.L.‘Electrophysiological evidence for a postperceptual locus of suppression during the attentional blink’.Journal of Experimental Psychology.Human Perception and Performance ,24,1656-74(1998);另请参阅 Sergent, Baillet&Dehaene,2005.
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61 Collins, T. F.T.et al.‘Dynamics of neuronal assemblies are modulated by anaesthetics but not analgesics’.European Journal of Anaesthesiology ,24,609-14(2007).
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62 Chakraborty, Sandberg&Greenfield,2007.
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63 Kendig, J. J.,Grossman, Y.&MacIver, M.B.‘Pressure reversal of anaesthesia:a synaptic mechanism’.British Journal of Anaesthesia ,60,806-16(1988).
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64 Wlodarczyk, A.,McMillan, P. F.&Greenfield, S.A.‘High pressure effects in anaesthesia and narcosis’.Chemical Society Reviews ,35,890-8(2006).
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65 Wu, J.-Y.,Xiaoying Huang&Chuan Zhang.‘Propagating waves of activity in the neocortex:what they are, what they do’. Neuroscientist,14,487-502(2008);另请参阅Muller, L.&Destexhe, A.‘Propagating waves in thalamus, cortex and the thalamocortical system:experiments and models’.Journal of Physiology-Paris ,106,222-38(2012).
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66 Ferreira, P. G.The State of the Universe .(Phoenix,2007).
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