Journal of Comparative Physiology A

, Volume 199, Issue 1, pp 1–16 | Cite as

Coding of abstract quantity by ‘number neurons’ of the primate brain



Humans share with nonhuman animals a quantification system for representing the number of items as nonverbal mental magnitudes. Over the past decade, the anatomical substrates and neuronal mechanisms of this quantification system have been unraveled down to the level of single neurons. Work with behaviorally trained nonhuman primates identified a parieto-frontal cortical network with individual neurons selectively tuned to the number of items. Such ‘number neurons’ can track items across space, time, and modality to encode numerosity in a most abstract, supramodal way. The physiological properties of these neurons can explain fundamental psychophysical phenomena during numerosity judgments. Functionally overlapping groups of parietal neurons represent not only numerable-discrete quantity (numerosity), but also innumerable-continuous quantity (extent) and relations between quantities (proportions), supporting the idea of a generalized magnitude system in the brain. These studies establish putative homologies between the monkey and human brain and demonstrate the suitability of nonhuman primates as model system to explore the neurobiological roots of the brain’s nonverbal quantification system, which may constitute the evolutionary foundation of all further, more elaborate numerical skills in humans.


Single-neuron recordings Parietal cortex Prefrontal cortex Rhesus monkey Abstract categories 



Anterior inferior temporal cortex




Broad spiking neuron


Functional magnetic resonance imaging


Intraparietal sulcus


Just noticable difference


Lateral intraparietal area


Narrow spiking neuron


Prefrontal cortex


Posterior parietal cortex


Superior parietal lobule


Ventral intraparietal area


  1. Agrillo C, Dadda M, Bisazza A (2007) Quantity discrimination in female mosquitofish. Anim Cogn 10:63–70PubMedCrossRefGoogle Scholar
  2. Ansari D, Garcia N, Lucas E, Hamon K, Dhital B (2005) Neural correlates of symbolic number processing in children and adults. NeuroReport 16:1769–1773PubMedCrossRefGoogle Scholar
  3. Barlow H (1995) The neuron doctrine in perception. In: Gazzaniga, Michael S (eds) The cognitive neurosciences. MIT Press, Cambridge, pp 415–435Google Scholar
  4. Benson-Amram S, Heinen VK, Dryer SL, Holekamp KE (2011) Numerical assessment and individual call discrimination by wild spotted hyaenas, Crocuta crocuta. Anim Behav 82:743–752CrossRefGoogle Scholar
  5. Beran MJ (2007) Rhesus monkeys (Macaca mulatta) enumerate large and small sequentially presented sets of items using analog numerical representations. J Exp Psychol Anim Behav Process 33:42–54PubMedCrossRefGoogle Scholar
  6. Bogale BA, Kamata N, Mioko K, Sugita S (2011) Quantity discrimination in jungle crows, Corvus macrorhynchos. Anim Behav 82:635–641CrossRefGoogle Scholar
  7. Bongard S, Nieder A (2010) Basic mathematical rules are encoded by primate prefrontal cortex neurons. Proc Natl Acad Sci USA 107:2277–2282PubMedCrossRefGoogle Scholar
  8. Boysen ST, Berntson GG (1989) Numerical competence in a chimpanzee (Pan troglodytes). J Comp Psychol 103:23–31PubMedCrossRefGoogle Scholar
  9. Brannon EM, Terrace HS (1998) Ordering of the numerosities 1 to 9 by monkeys. Science 282:746–749PubMedCrossRefGoogle Scholar
  10. Bremmer F, Schlack A, Shah NJ, Zafiris O, Kubischik M, Hoffmann K, Zilles K, Fink GR (2001) Polymodal motion processing in posterior parietal and premotor cortex: a human fMRI study strongly implies equivalencies between humans and monkeys. Neuron 29:287–296PubMedCrossRefGoogle Scholar
  11. Cantlon JF, Brannon EM (2005) Semantic congruity affects numerical judgments similarly in monkeys and humans. Proc Natl Acad Sci USA 102:16507–16511PubMedCrossRefGoogle Scholar
  12. Cantlon JF, Brannon EM (2006) Shared system for ordering small and large numbers in monkeys and humans. Psychol Sci 17:401–406PubMedCrossRefGoogle Scholar
  13. Cantlon JF, Libertus ME, Pinel P, Dehaene S, Brannon EM, Pelphrey KA (2009) The neural development of an abstract concept of number. J Cogn Neurosci 21:2217–2229PubMedCrossRefGoogle Scholar
  14. Castelli F, Glaser DE, Butterworth B (2006) Discrete and analogue quantity processing in the parietal lobe: a functional MRI study. Proc Natl Acad Sci USA 103:4693–4698PubMedCrossRefGoogle Scholar
  15. Chafee MV, Goldman-Rakic PS (2000) Inactivation of parietal and prefrontal cortex reveals interdependence of neural activity during memory-guided saccades. J Neurophysiol 83:1550–1566PubMedGoogle Scholar
  16. Colby CL, Goldberg ME (1999) Space and attention in parietal cortex. Annu Rev Neurosci 22:319–349PubMedCrossRefGoogle Scholar
  17. Colby CL, Duhamel JR, Goldberg ME (1993) Ventral intraparietal area of the macaque—anatomical location and visual response properties. J Neurophysiol 69:902–914PubMedGoogle Scholar
  18. Connors BW, Gutnick MJ (1990) Intrinsic firing patterns of diverse neocortical neurons. Trends Neurosci 13:99–104PubMedCrossRefGoogle Scholar
  19. Cordes S, Gelman R, Gallistel CR, Whalen J (2001) Variability signatures distinguish verbal from nonverbal counting for both large and small numbers. Psychonom Bull Rev 8:698–707CrossRefGoogle Scholar
  20. Dacke M, Srinivasan MV (2008) Evidence for counting in insects. Anim Cogn 11:683–689PubMedCrossRefGoogle Scholar
  21. Davis H, Pérusse R (1988) Numerical competence in animals: definitional issues, current evidence, and a new research agenda. Behav Brain Sci 11:561–615CrossRefGoogle Scholar
  22. Dehaene S (1992) Varieties of numerical abilities. Cognition 44:1–42PubMedCrossRefGoogle Scholar
  23. Dehaene S (2005) Evolution of human cortical circuits for reading and arithmetic: the “neuronal recycling” hypothesis. In: Dehaene S, Duhamel JR, Hauser MD, Rizzolatti G (eds) From monkey brain to human brain. MIT Press, Cambridge, pp 133–157Google Scholar
  24. Dehaene S (2011) The number sense: how the mind creates mathematics. Oxford University Press, OxfordGoogle Scholar
  25. Dehaene S, Changeux JP (1993) Development of elementary numerical abilities: a neural model. J Cogn Neurosci 5:390–407CrossRefGoogle Scholar
  26. Dehaene S, Cohen L (2007) Cultural recycling of cortical maps. Neuron 56:384–398PubMedCrossRefGoogle Scholar
  27. Dehaene S, Spelke E, Pinel P, Stanescu R, Tsivkin S (1999) Sources of mathematical thinking: behavioral and brain-imaging evidence. Science 284:970–974PubMedCrossRefGoogle Scholar
  28. Dehaene S, Molko N, Cohen L, Wilson AJ (2004) Arithmetic and the brain. Curr Opin Neurobiol 14:218–224PubMedCrossRefGoogle Scholar
  29. Desimone R (1996) Neural mechanisms for visual memory and their role in attention. Proc Natl Acad Sci USA 93:13494–13499PubMedCrossRefGoogle Scholar
  30. Diester I, Nieder A (2007) Semantic associations between signs and numerical categories in the prefrontal cortex. PLoS Biol 5:e294PubMedCrossRefGoogle Scholar
  31. Diester I, Nieder A (2008) Complementary contributions of prefrontal neuron classes in abstract numerical categorization. J Neurosci 28:7737–7747PubMedCrossRefGoogle Scholar
  32. Diester I, Nieder A (2010) Numerical values leave a semantic imprint on associated signs in monkeys. J Cogn Neurosci 22:174–183PubMedCrossRefGoogle Scholar
  33. Doricchi F, Guariglia P, Gasparini M, Tomaiuolo F (2005) Dissociation between physical and mental number line bisection in right hemisphere brain damage. Nat Neurosci 8:1663–1665PubMedCrossRefGoogle Scholar
  34. Dormal V, Dormal G, Joassin F, Pesenti M (2012) A common right fronto-parietal network for numerosity and duration processing: an fMRI study. Hum Brain Mapp 33:1490–1501PubMedCrossRefGoogle Scholar
  35. Eger E, Sterzer P, Russ MO, Giraud AL, Kleinschmidt A (2003) A supramodal number representation in human intraparietal cortex. Neuron 37:719–725PubMedCrossRefGoogle Scholar
  36. Emery NJ, Clayton NS (2004) The mentality of crows: convergent evolution of intelligence in corvids and apes. Science 306:1903–1907PubMedCrossRefGoogle Scholar
  37. Evans TA, Beran MJ, Harris EH, Rice DF (2009) Quantity judgments of sequentially presented food items by capuchin monkeys (Cebus apella). Anim Cogn 12:97–105PubMedCrossRefGoogle Scholar
  38. Evarts EV (1966) Methods for recording activity of individual neurons in moving animals. In: Rushmer RF (ed) Methods in medical research. Year Book, Chicago, pp 241–250Google Scholar
  39. Fias W, Lammertyn J, Reynvoet B, Dupont P, Orban GA (2003) Parietal representation of symbolic and nonsymbolic magnitude. J Cogn Neurosci 15:47–56PubMedCrossRefGoogle Scholar
  40. Freedman DJ, Riesenhuber M, Poggio T, Miller EK (2001) Categorical representation of visual stimuli in the primate prefrontal cortex. Science 291:312–316PubMedCrossRefGoogle Scholar
  41. Fuster JM (2001) The prefrontal cortex—an update: time is of the essence. Neuron 30:319–333PubMedCrossRefGoogle Scholar
  42. Fuster J (2008) The prefrontal cortex, 4th edn. Academic Press, LondonGoogle Scholar
  43. Fuster JM, Bodner M, Kroger JK (2000) Cross-modal and cross-temporal association in neurons of frontal cortex. Nature 405:347–351PubMedCrossRefGoogle Scholar
  44. Genovesio A, Tsujimoto S, Wise SP (2006) Neuronal activity related to elapsed time in prefrontal cortex. J Neurophysiol 95:3281–3285PubMedCrossRefGoogle Scholar
  45. Genovesio A, Tsujimoto S, Wise SP (2011) Prefrontal cortex activity during the discrimination of relative distance. J Neurosci 31:3968–3980PubMedCrossRefGoogle Scholar
  46. Gerstmann J (1940) Syndrome of finger agnosia, disorientation for right and left agraphia and acalculia. Arch Neurol Psychiatry 44:398–408CrossRefGoogle Scholar
  47. Gordon P (2004) Numerical cognition without words: evidence from Amazonia. Science 306:496–499PubMedCrossRefGoogle Scholar
  48. Gould SJVE (1982) Exaptation: a missing term in the science of form. Paleobiology 8:4–15Google Scholar
  49. Henik A, Tzelgov J (1982) Is three greater than five: the relation between physical and semantic size in comparison tasks. Mem Cogn 10:389–395CrossRefGoogle Scholar
  50. Henschen SE (1919) Über Sprach-, Musik und Rechenmechanismen und ihre Lokalisation im Großhirn. Z. ges. Neurologie und Psychiatrie 52:273–298Google Scholar
  51. Hoffmann A, Ruettler V, Nieder A (2011) Ontogeny of object permanence and object tracking in the carrion crow, Corvus corone. Anim Behav 82:359–367CrossRefGoogle Scholar
  52. Ifrah G (2000) The universal history of numbers: from prehistory to the invention of the computer. Wiley, New YorkGoogle Scholar
  53. Jacob SN, Nieder A (2008) The ABC of cardinal and ordinal number representations. Trends Cogn Sci 12:41–43PubMedCrossRefGoogle Scholar
  54. Jacob SN, Nieder A (2009a) Notation-independent representation of fractions in the human parietal cortex. J Neurosci 29:4652–4657PubMedCrossRefGoogle Scholar
  55. Jacob SN, Nieder A (2009b) Tuning to non-symbolic proportions in the human frontoparietal cortex. Eur J Neurosci 30:1432–1442PubMedCrossRefGoogle Scholar
  56. Jacob SN, Vallentin D, Nieder A (2012) Relating magnitudes: the brain’s code for proportions. Trends Cogn Sci 16:157–166PubMedCrossRefGoogle Scholar
  57. Jasper HH, Ricci G, Doane B (1960) Microelectrode analysis of cortical cell discharge during avoidance conditioning in the monkey. Int J Electroencephalogr Clin Neurophysiol Suppl 131:137–156Google Scholar
  58. Kaufmann L, Koppelstaetter F, Siedentopf C, Haala I, Haberlandt E et al (2006) Neural correlates of the number-size interference task in children. NeuroReport 17:587–591PubMedCrossRefGoogle Scholar
  59. Koehler O (1941) Vom Erlernen unbenannter Anzahlen bei Vögeln. Naturwissenschaften 29:201–218CrossRefGoogle Scholar
  60. Koehler O (1951) The ability of birds to “count”. Bull Anim Behav 9:41–45Google Scholar
  61. Kohonen T (1997) Self-organizing maps, 2nd edn. Springer, BerlinCrossRefGoogle Scholar
  62. Laubach M (2004) Wavelet-based processing of neuronal spike trains prior to discriminant analysis. J Neurosci Meth 134:159–168CrossRefGoogle Scholar
  63. Leon MI, Shadlen MN (2003) Representation of time by neurons in the posterior parietal cortex of the macaque. Neuron 38:317–327PubMedCrossRefGoogle Scholar
  64. Lewis JW, Van Essen DC (2000) Corticocortical connections of visual, sensorimotor, and multimodal processing areas in the parietal lobe of the macaque monkey. J Comp Neurol 428:112–137PubMedCrossRefGoogle Scholar
  65. Logothetis NK, Pauls J, Augath M, Trinath T, Oeltermann A (2001) Neurophysiological investigation of the basis of the fMRI signal. Nature 412:150–157PubMedCrossRefGoogle Scholar
  66. Luria AR (1966) Higher cortical functions in man. Tavistock, LondonGoogle Scholar
  67. Lyon BE (2003) Egg recognition and counting reduce costs of avian conspecific brood parasitism. Nature 422:495–499PubMedCrossRefGoogle Scholar
  68. Markram H, Toledo-Rodriguez M, Wang Y, Gupta A, Silberberg G, Wu C (2004) Interneurons of the neocortical inhibitory system. Nat Rev Neurosci 5:793–807PubMedCrossRefGoogle Scholar
  69. Matsuzawa T (1985) Use of numbers by a chimpanzee. Nature 315:57–59PubMedCrossRefGoogle Scholar
  70. McComb K, Packer C, Pusey A (1994) Roaring and numerical assessment in contests between groups of female lions, Panthera leo. Anim Behav 47:379–387CrossRefGoogle Scholar
  71. Meck WH, Church RM (1983) A mode control model of counting and timing processes. J Exp Psychol: Anim Behav Process 9:320–334CrossRefGoogle Scholar
  72. Merten K, Nieder A (2009) Compressed scaling of abstract numerosity representations in adult humans and monkeys. J Cogn Neurosci 21:333–346PubMedCrossRefGoogle Scholar
  73. Merten K, Nieder A (2012) Active encoding of decisions about stimulus absence in primate prefrontal cortex neurons. Proc Natl Acad Sci USA 109:6289–6294PubMedCrossRefGoogle Scholar
  74. Miller EK, Cohen JD (2001) An integrative theory of prefrontal cortex function. Annu Rev Neurosci 24:167–202PubMedCrossRefGoogle Scholar
  75. Miller EK, Erickson CA, Desimone R (1996) Neural mechanisms of visual working memory in prefrontal cortex of the macaque. J Neurosci 16:5154–5167PubMedGoogle Scholar
  76. Mita A, Mushiake H, Shima K, Matsuzaka Y, Tanji J (2009) Interval time coding by neurons in the presupplementary and supplementary motor areas. Nat Neurosci 12:502–507PubMedCrossRefGoogle Scholar
  77. Nieder A (2005) Counting on neurons: the neurobiology of numerical competence. Nat Rev Neurosci 6:177–190Google Scholar
  78. Nieder A (2009) Prefrontal cortex and the evolution of symbolic reference. Curr Opin Neurobiol 19:99–108PubMedCrossRefGoogle Scholar
  79. Nieder A (2012) Supramodal numerosity selectivity of neurons in primate prefrontal and posterior parietal cortices. Proc Natl Acad Sci USA 109:11860–11865PubMedCrossRefGoogle Scholar
  80. Nieder A, Dehaene S (2009) Representation of number in the brain. Annu Rev Neurosci 32:185–208PubMedCrossRefGoogle Scholar
  81. Nieder A, Merten K (2007) A labeled-line code for small and large numerosities in the monkey prefrontal cortex. J Neurosci 27:5986–5993PubMedCrossRefGoogle Scholar
  82. Nieder A, Miller EK (2003) Coding of cognitive magnitude: compressed scaling of numerical information in the primate prefrontal cortex. Neuron 37:149–157PubMedCrossRefGoogle Scholar
  83. Nieder A, Miller EK (2004a) A parieto-frontal network for visual numerical information in the monkey. Proc Natl Acad Sci USA 101:7457–7462PubMedCrossRefGoogle Scholar
  84. Nieder A, Miller EK (2004b) Analog numerical representations in rhesus monkeys: evidence for parallel processing. J Cogn Neurosci 16:889–901PubMedCrossRefGoogle Scholar
  85. Nieder A, Freedman DJ, Miller EK (2002) Representation of the quantity of visual items in the primate prefrontal cortex. Science 297:1708–1711PubMedCrossRefGoogle Scholar
  86. Nieder A, Diester I, Tudusciuc O (2006) Temporal and spatial enumeration processes in the primate parietal cortex. Science 313:1431–1435PubMedCrossRefGoogle Scholar
  87. Onoe H, Komori M, Onoe K, Takechi H, Tsukada H, Watanabe Y (2001) Cortical networks recruited for time perception: a monkey positron emission tomography (PET) study. Neuroimage 13:37–45PubMedCrossRefGoogle Scholar
  88. Piazza M, Dehaene S (2004) From number neurons to mental arithmetic: the cognitive neuroscience of number sense. In: Gazzaniga M (ed) The cognitive neurosciences, 3rd edn. MIT Press, CambridgeGoogle Scholar
  89. Piazza M, Izard V, Pinel P, Le Bihan D, Dehaene S (2004) Tuning curves for approximate numerosity in the human intraparietal sulcus. Neuron 44:547–555PubMedCrossRefGoogle Scholar
  90. Pica P, Lemer C, Izard V, Dehaene S (2004) Exact and approximate arithmetic in an Amazonian indigene group. Science 306:499–503PubMedCrossRefGoogle Scholar
  91. Pinel P, Piazza M, Le Bihan D, Dehaene S (2004) Distributed and overlapping cerebral representations of number, size, and luminance during comparative judgments. Neuron 41:983–993PubMedCrossRefGoogle Scholar
  92. Quintana J, Fuster JM, Yajeya J (1989) Effects of cooling parietal cortex on prefrontal units in delay tasks. Brain Res 503:100–110PubMedCrossRefGoogle Scholar
  93. Rainer G, Rao SC, Miller EK (1999) Prospective coding for objects in primate prefrontal cortex. J Neurosci 19:5493–5505PubMedGoogle Scholar
  94. Rivera SM, Reiss AL, Eckert MA, Menon V (2005) Developmental changes in mental arithmetic: evidence for increased functional specialization in the left inferior parietal cortex. Cereb Cortex 15:1779–1790PubMedCrossRefGoogle Scholar
  95. Roitman JD, Brannon EM, Platt ML (2007) Monotonic coding of numerosity in macaque lateral intraparietal area. PLoS Biol 8:e208CrossRefGoogle Scholar
  96. Sawamura H, Shima K, Tanji J (2002) Numerical representation for action in the parietal cortex of the monkey. Nature 415:918–922PubMedCrossRefGoogle Scholar
  97. Sawamura H, Shima K, Tanji J (2010) Deficits in action selection based on numerical information after inactivation of the posterior parietal cortex in monkeys. J Neurophysiol 104:902–910PubMedCrossRefGoogle Scholar
  98. Scarf D, Hayne H, Colombo M (2011) Pigeons on par with primates in numerical competence. Science 334:1664PubMedCrossRefGoogle Scholar
  99. Smirnova AA, Lazareva OF, Zorina ZA (2000) Use of number by crows: investigation by matching and oddity learning. J Exp Anal Behav 73:163–176PubMedCrossRefGoogle Scholar
  100. Stoet G, Snyder LH (2004) Single neurons in posterior parietal cortex of monkeys encode cognitive set. Neuron 42:1003–1012PubMedCrossRefGoogle Scholar
  101. Stoet G, Snyder LH (2009) Neural correlates of executive control functions in the monkey. Trends Cogn Sci 13:228–234PubMedCrossRefGoogle Scholar
  102. Stoianov I, Zorzi M (2012) Emergence of a ‘visual number sense’ in hierarchical generative models. Nat Neurosci 15:194–196PubMedCrossRefGoogle Scholar
  103. Tanaka K (1996) Inferotemporal cortex and object vision. Annu Rev Neurosci 19:109–139PubMedCrossRefGoogle Scholar
  104. Tomita H, Ohbayashi M, Nakahara K, Hasegawa I, Miyashita Y (1999) Top-down signal from prefrontal cortex in executive control of memory retrieval. Nature 401:699–703PubMedCrossRefGoogle Scholar
  105. Tudusciuc O, Nieder A (2007) Neuronal population coding of continuous and discrete quantity in the primate posterior parietal cortex. Proc Natl Acad Sci USA 104:14513–14518PubMedCrossRefGoogle Scholar
  106. Tudusciuc O, Nieder A (2009) Contributions of primate prefrontal and posterior parietal cortices to length and numerosity representation. J Neurophysiol 101:2984–2994PubMedCrossRefGoogle Scholar
  107. Tudusciuc O, Nieder A (2010) Comparison of length judgments and the Müller-Lyer illusion in monkeys and humans. Exp Brain Res 207:221–231PubMedCrossRefGoogle Scholar
  108. Uller C, Jaeger R, Guidry G, Martin C (2003) Salamanders (Plethodon cinereus) go for more: rudiments of number in an amphibian. Anim Cogn 6:105–112PubMedGoogle Scholar
  109. Vallentin D, Nieder A (2008) Behavioural and prefrontal representation of spatial proportions in the monkey. Curr Biol 18:1420–1425PubMedCrossRefGoogle Scholar
  110. Vallentin D, Nieder A (2010) Representations of visual proportions in the primate posterior parietal and prefrontal cortices. Eur J Neurosci 32:1380–1387PubMedCrossRefGoogle Scholar
  111. Vallentin D, Bongard S, Nieder A (2012) Numerical rule coding in the prefrontal, premotor, and posterior parietal cortices of macaques. J Neurosci 32:6621–6630PubMedCrossRefGoogle Scholar
  112. Verguts T, Fias W (2004) Representation of number in animals and humans: a neural model. J Cogn Neurosci 16:1493–1504PubMedCrossRefGoogle Scholar
  113. Wallis JD, Anderson KC, Miller EK (2001) Single neurons in prefrontal cortex encode abstract rules. Nature 411:953–956PubMedCrossRefGoogle Scholar
  114. Walsh V (2003) A theory of magnitude: common cortical metrics of time, space and quantity. Trends Cogn Sci 7:483–488PubMedCrossRefGoogle Scholar
  115. Washburn DA (1994) Stroop-like effects for monkeys and humans: processing speed or strength of association? Psychol Sci 5:375–379PubMedCrossRefGoogle Scholar
  116. Washburn DA, Rumbaugh DM (1991) Ordinal judgments of numerical symbols by macaques (Macaca mulatta). Psychol Sci 2:190–193PubMedCrossRefGoogle Scholar
  117. Whalen J, Gallistel CR, Gelman R (1999) Nonverbal counting in humans: the psychophysics of number representation. Psychol Sci 10:130–137CrossRefGoogle Scholar
  118. Wilson ML, Kahlenberg SM, Wells M, Wrangham RW (2012) Ecological and social factors affect the occurrence and outcomes of intergroup encounters in chimpanzees. Anim Behav 83:277–291CrossRefGoogle Scholar
  119. Wonders CP, Anderson SA (2006) The origin and specification of cortical interneurons. Nat Rev Neurosci 7:687–696PubMedCrossRefGoogle Scholar
  120. Xia L, Emmerton J, Siemann M, Delius JD (2001) Pigeons (Columba livia) learn to link numerosities with symbols. J Comp Psychol 115:83–91PubMedCrossRefGoogle Scholar

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© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Animal Physiology, Institute of NeurobiologyUniversity of TübingenTübingenGermany

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