41. Wada M, Yoshimi K, Higo N, Ren YR, Mochizuki H, et al. (2006) Statistical parametric mapping of immunopositive cell density. Neurosci Res. 56: 96–102. 42. Schwarz AJ, Danckaert A, Reese T, Gozzi A, Paxinos G, et al. (2006) A stereotaxic MRI template set for the rat brain with tissue class distribution maps and co-registered anatomical atlas: application to pharmacological MRI. Neuroimage 32: 538–550. 43. Van Essen DC, Drury HA, Joshi S, Miller MI (1998) Functional and structural mapping of human cerebral cortex: solutions are in the surfaces. Proc Natl Acad Sci U S A 95: 788–795. 44. Welker C (1976) Receptive fields of barrels in the somatosensory neocortex of the rat. J Comp Neurol 166: 173–189. 45. Chapin JK, Sadeq M, Guise JL (1987) Corticocortical connections within the primary somatosensory cortex of the rat. J Comp Neurol 263: 326–346. 46. Fabri M, Burton H (1991) Ipsilateral cortical connections of primary somatic sensory cortex in rats. J Comp Neurol 311: 405–424. 47. Killackey HP, Sherman SM (2003) Corticothalamic projections from the rat primary somatosensory cortex. J Neurosci. 23: 7381–7384. 48. Arnault P, Roger M (1990) Ventral temporal cortex in the rat: connections of secondary auditory areas Te2 and Te3. J Comp Neurol 302: 110–123. 49. Paxinos G, Watson C (1997) The Rat Brain in Stereotaxic Coordinates (3rd ed.). Sydney: Academic Press. 50. Swanson L (2004) Brain maps: structure of the rat brain (3rd ed.). Amsterdam: Elsevier Academic Press. 51. Geyer S, Matelli M, Luppino G, Schleicher A, Jansen Y, et al. (1998) Receptor autoradiographic mapping of the mesial motor and premotor cortex of the macaque monkey. J Comp Neurol 397: 231–250. 52. Livingstone MS, Hubel DH (1982) Thalamic inputs to cytochrome oxidase-rich regions in monkey visual cortex. Proc Natl Acad Sci U S A 79: 6098–6101. 53. Ding Y, Casagrande VA (1998) Synaptic and neurochemical characterization of parallel pathways to the cytochrome oxidase blobs of primate visual cortex. J Comp Neurol 391: 429–443. ISH Profiling of Rat Cortex 54. Wong Riley M (1979) Changes in the visual system of monocularly sutured or enucleated cats demonstrable with cytochrome oxidase histochemistry. Brain Res 171: 11–28. 55. Wong Riley MT, Welt C (1980) Histochemical changes in cytochrome oxidase of cortical barrels after vibrissal removal in neonatal and adult mice. Proc Natl Acad Sci U S A 77: 2333–2337. 56. Dragunow M (1996) A role for immediate-early transcription factors in learning and memory. Behav Genet 26: 293–299. 57. Mataga N, Fujishima S, Condie BG, Hensch TK (2001) Experience-dependent plasticity of mouse visual cortex in the absence of the neuronal activity- dependent marker egr1/zif268. J Neurosci 21: 9724–9732. 58. Sur M, Rubenstein JL (2005) Patterning and plasticity of the cerebral cortex. Science 310: 805–810. 59. Lu SM, Lin RC (1993) Thalamic afferents of the rat barrel cortex: a light- and electron-microscopic study using Phaseolus vulgaris leucoagglutinin as an anterograde tracer. Somatosens Mot Res 10: 1–16. 60. Pierret T, Lavallee P, Deschenes M (2000) Parallel streams for the relay of vibrissal information through thalamic barreloids. J Neurosci 20: 7455–7462. 61. Douglas RJ, Martin KA (2004) Neuronal circuits of the neocortex. Annu Rev Neurosci 27: 419–451. 62. Bishop KM, Goudreau G, O’Leary DD (2000) Regulation of area identity in the mammalian neocortex by Emx2 and Pax6. Science 288: 344–349. 63. Bayer SA, Altman J (1991) Neocortical development. New York: Raven Press. 64. Liang F, Hatanaka Y, Saito H, Yamamori T, Hashikawa T (2000) Differential expression of gamma-aminobutyric acid type B receptor-1a and -1b mRNA variants in GABA and non-GABAergic neurons of the rat brain. J Comp Neurol 416: 475–495. 65. Briggman KL, Abarbanel HD, Kristan WB Jr (2005) Optical imaging of neuronal populations during decision-making. Science 307: 896–901. PLoS ONE | www.plosone.org 13 September 2008 | Volume 3 | Issue 9 | e3266