title: Architectonic subdivisions of neocortex in the gray squirrel (Sciurus carolinensis).
abstract: Squirrels are highly visual mammals with an expanded cortical visual system and a number of well-differentiated architectonic fields. To describe and delimit cortical fields, subdivisions of cortex were reconstructed from serial brain sections cut in the coronal, sagittal, or horizontal planes. Architectonic characteristics of cortical areas were visualized after brain sections were processed with immunohistochemical and histochemical procedures for revealing parvalbumin, calbindin, neurofilament protein, vesicle glutamate transporter 2, limbic-associated membrane protein, synaptic zinc, cytochrome oxidase, myelin or Nissl substance. In general, these different procedures revealed similar boundaries between areas, suggesting that functionally relevant borders were being detected. The results allowed a more precise demarcation of previously identified areas as well as the identification of areas that had not been previously described. Primary sensory cortical areas were characterized by sparse zinc staining of layer 4, as thalamocortical terminations lack zinc, as well as by layer 4 terminations rich in parvalbumin and vesicle glutamate transporter 2. Primary areas also expressed higher levels of cytochrome oxidase and myelin. Primary motor cortex was associated with large SMI-32 labeled pyramidal cells in layers 3 and 5. Our proposed organization of cortex in gray squirrels includes both similarities and differences to the proposed of cortex in other rodents such as mice and rats. The presence of a number of well-differentiated cortical areas in squirrels may serve as a guide to the identification of homologous fields in other rodents, as well as a useful guide in further studies of cortical organization and function.
authors.affiliation: Department of Psychology, Vanderbilt University, Nashville, Tennessee, USA.
authors.forename: Peiyan
authors.initials: P
authors.lastname: Wong
authors.forename: Jon H
authors.initials: JH
authors.lastname: Kaas
mesh_terms: D000818:Animals; D005625:Frontal Lobe / Q000033:anatomy & histology; D006179:Gyrus Cinguli / Q000033:anatomy & histology; D009044:Motor Cortex / Q000033:anatomy & histology; D019579:Neocortex / Q000033:anatomy & histology*; D009778:Occipital Lobe / Q000033:anatomy & histology; D012589:Sciuridae / Q000033:anatomy & histology*; D013702:Temporal Lobe / Q000033:anatomy & histology; D014793:Visual Cortex / Q000033:anatomy & histology*
references.citation: J Comp Neurol. 2008 Mar 10;507(2):1151-68
references.pmid: 18175349
references.citation: Histochemistry. 1982;76(3):281-93
references.pmid: 6186642
references.citation: Brain Behav Evol. 2002;59(5-6):262-72
references.pmid: 12207083
references.citation: J Neurophysiol. 1965 Mar;28:229-89
references.pmid: 14283058
references.citation: Brain Res. 1991 Oct 18;562(1):39-47
references.pmid: 1799871
references.citation: Hear Res. 2003 Jul;181(1-2):116-30
references.pmid: 12855370
references.citation: J Comp Neurol. 2003 Aug 25;463(3):317-40
references.pmid: 12820165
references.citation: J Hirnforsch. 1986;27(2):121-43
references.pmid: 3722803
references.citation: J Comp Neurol. 1973 Jan 15;147(2):163-79
references.pmid: 4630151
references.citation: J Comp Neurol. 1993 Mar 1;329(1):53-67
references.pmid: 8384221
references.citation: J Nutr. 2000 May;130(5S Suppl):1471S-83S
references.pmid: 10801962
references.citation: J Comp Neurol. 1988 Feb 8;268(2):181-203
references.pmid: 3360984
references.citation: Vis Neurosci. 2006 Sep-Oct;23(5):765-78
references.pmid: 17020632
references.citation: Science. 2007 Oct 26;318(5850):655-8
references.pmid: 17962567
references.citation: J Comp Neurol. 1978 May 15;179(2):425-49
references.pmid: 417097
references.citation: J Comp Neurol. 1987 Feb 8;256(2):246-56
references.pmid: 3558880
references.citation: Brain Res. 1971 Mar 5;26(2):277-92
references.pmid: 5547178
references.citation: Anat Embryol (Berl). 1980;159(3):335-60
references.pmid: 6970009
references.citation: Cereb Cortex. 1992 Nov-Dec;2(6):435-43
references.pmid: 1477524
references.citation: J Comp Neurol. 2007 Mar 1;501(1):121-49
references.pmid: 17206607
references.citation: Prog Brain Res. 2001;134:285-95
references.pmid: 11702549
references.citation: J Physiol. 1973 Jul;232(2):275-83
references.pmid: 4727082
references.citation: Cereb Cortex. 1998 Jun;8(4):362-71
references.pmid: 9651131
references.citation: J Chem Neuroanat. 1997 Dec;14(1):1-19
references.pmid: 9498163
references.citation: J Comp Neurol. 1976 Apr 15;166(4):387-401
references.pmid: 1270613
references.citation: Hippocampus. 2007;17(9):709-22
references.pmid: 17604355
references.citation: Eur J Neurosci. 1993 Jul 1;5(7):882-97
references.pmid: 8281300
references.citation: J Chem Neuroanat. 2005 May;29(3):193-208
references.pmid: 15820621
references.citation: Cereb Cortex. 2004 Nov;14(11):1173-84
references.pmid: 15142953
references.citation: Brain Res. 1986 Mar;396(1):77-96
references.pmid: 3708387
references.citation: Physiol Rev. 1983 Jan;63(1):206-31
references.pmid: 6401864
references.citation: Exp Neurol. 1973 Mar-Apr;39(2):270-6
references.pmid: 4702821
references.citation: Anat Embryol (Berl). 1990;181(1):67-73
references.pmid: 2407148
references.citation: Proc Natl Acad Sci U S A. 2007 Jul 3;104(27):11459-64
references.pmid: 17592148
references.citation: J Comp Neurol. 2006 Jul 1;497(1):133-54
references.pmid: 16680767
references.citation: J Comp Neurol. 1987 Nov 22;265(4):549-80
references.pmid: 2448348
references.citation: J Comp Neurol. 2001 Aug 13;437(1):17-41
references.pmid: 11477594
references.citation: J Comp Neurol. 1981 Sep 10;201(2):265-83
references.pmid: 7287929
references.citation: Neuropsychologia. 1996 Aug;34(8):741-74
references.pmid: 8817506
references.citation: J Comp Neurol. 1989 Apr 8;282(2):191-205
references.pmid: 2496154
references.citation: J Physiol. 1980 Feb;299:247-76
references.pmid: 7381768
references.citation: J Comp Neurol. 2004 Nov 8;479(2):156-67
references.pmid: 15452827
references.citation: J Comp Neurol. 1999 Aug 30;411(3):503-23
references.pmid: 10413783
references.citation: J Comp Neurol. 1992 Jul 15;321(3):357-72
references.pmid: 1380516
references.citation: Cereb Cortex. 2004 Nov;14(11):1276-86
references.pmid: 15166101
references.citation: J Comp Neurol. 1998 Aug 24;398(2):179-205
references.pmid: 9700566
references.citation: J Comp Neurol. 1982 Apr 10;206(3):227-42
references.pmid: 7085930
references.citation: J Comp Neurol. 1979 Jun 15;185(4):657-78
references.pmid: 447876
references.citation: J Comp Neurol. 2004 Sep 13;477(2):172-87
references.pmid: 15300788
references.citation: Brain Behav Evol. 2000 Oct;56(4):212-34
references.pmid: 11155000
references.citation: Cereb Cortex. 2000 Mar;10(3):206-19
references.pmid: 10731217
references.citation: J Neurophysiol. 1971 May;34(3):437-52
references.pmid: 5560040
references.citation: Science. 1984 Jan 20;223(4633):299-301
references.pmid: 6199842
references.citation: J Neurosci. 1991 Jan;11(1):226-37
references.pmid: 1702464
references.citation: Brain Res. 1969 Feb;12(2):296-320
references.pmid: 4185473
references.citation: Neurol Res. 1979;1(2):203-9
references.pmid: 95356
references.citation: J Comp Neurol. 2004 Nov 22;479(4):360-73
references.pmid: 15514982
references.citation: J Comp Neurol. 1982 Nov 20;212(1):76-88
references.pmid: 6294151
references.citation: Brain Res. 1998 Jan 19;781(1-2):137-47
references.pmid: 9507093
references.citation: J Comp Neurol. 1984 Oct 20;229(2):199-213
references.pmid: 6438190
references.citation: Exp Brain Res. 1993;94(1):1-15
references.pmid: 8335065
references.citation: J Neurophysiol. 2007 May;97(5):3621-38
references.pmid: 17376842
references.citation: Brain Behav Evol. 1970;3(1):155-68
references.pmid: 5522341
references.citation: Brain Res. 1975 Jul 25;93(1):133-9
references.pmid: 49213
references.citation: J Comp Neurol. 1983 Apr 1;215(2):135-53
references.pmid: 6853769
references.citation: Brain Behav Evol. 1994;43(3):162-72
references.pmid: 8193908
references.citation: J Comp Neurol. 1983 May 10;216(2):192-210
references.pmid: 6863602
references.citation: Proc Natl Acad Sci U S A. 1993 Feb 15;90(4):1425-9
references.pmid: 8434002
references.citation: J Cogn Neurosci. 1995 Winter;7(1):1-24
references.pmid: 23961750
references.citation: J Comp Neurol. 1981 Feb 1;195(4):603-25
references.pmid: 7462444
references.citation: Histochemistry. 1981;71(1):1-16
references.pmid: 6785259
references.citation: J Comp Neurol. 1956 Oct;105(3):417-537
references.pmid: 13385382
references.citation: Exp Brain Res. 1984;54(2):240-52
references.pmid: 6723844
references.citation: J Comp Neurol. 1998 May 18;394(4):475-95
references.pmid: 9590556
references.citation: Brain Res. 1977 Jul 1;129(2):346-52
references.pmid: 69471
references.citation: Neurosci Res. 2002 Apr;42(4):243-50
references.pmid: 11985876
references.citation: J Comp Neurol. 1979 Apr 1;184(3):473-89
references.pmid: 422752
references.citation: Brain Res. 1979 Feb 9;161(3):539-43
references.pmid: 421136
references.citation: Vis Neurosci. 1994 Jul-Aug;11(4):731-41
references.pmid: 7918223
references.citation: J Comp Physiol Psychol. 1980 Dec;94(6):1087-100
references.pmid: 7204699
references.citation: Brain Res. 1991 Nov 1;563(1-2):293-6
references.pmid: 1786543
references.citation: J Neurosci. 1989 Nov;9(11):3741-52
references.pmid: 2479724
references.citation: Cereb Cortex. 2000 Feb;10(2):192-203
references.pmid: 10667987
references.citation: J Comp Neurol. 1986 Dec 8;254(2):143-65
references.pmid: 3794004
references.citation: Brain Res. 1982 Jun 24;242(2):332-6
references.pmid: 6180800
references.citation: J Comp Neurol. 1975 Nov 15;164(2):247-63
references.pmid: 1184785
references.citation: J Comp Neurol. 2005 Nov 14;492(2):145-77
references.pmid: 16196030
references.citation: J Comp Neurol. 2003 Dec 1;467(1):105-18
references.pmid: 14574683
references.citation: J Comp Neurol. 1989 Mar 15;281(3):426-46
references.pmid: 2703555
references.citation: Exp Brain Res. 2000 Jun;132(4):445-56
references.pmid: 10912825
references.citation: Somatosens Mot Res. 1990;7(3):315-35
references.pmid: 2248004
references.citation: J Neurophysiol. 1997 Jun;77(6):3193-217
references.pmid: 9212268
references.citation: Brain Res. 1980 May;203(1):1-43
references.pmid: 6994855
references.citation: Neuroscience. 2006;138(2):523-35
references.pmid: 16426767
references.citation: Somatosens Mot Res. 1992;9(1):3-36
references.pmid: 1317625
references.citation: Brain Res. 1970 Jan 20;17(2):205-42
references.pmid: 4904874
references.citation: Brain Res. 1997 Aug 29;767(1):148-53
references.pmid: 9365028
references.citation: Anat Embryol (Berl). 1991;184(5):461-8
references.pmid: 1741478
references.citation: Science. 1986 Feb 28;231(4741):995-7
references.pmid: 3945815
references.citation: Exp Neurol. 2002 Apr;174(2):215-29
references.pmid: 11922663
references.citation: J Comp Neurol. 1976 Aug 15;168(4):459-81
references.pmid: 939818
references.citation: J Comp Neurol. 1990 Apr 8;294(2):262-80
references.pmid: 2332532
references.citation: J Comp Neurol. 2001 Jul 2;435(3):379-87
references.pmid: 11406819
references.citation: Vis Neurosci. 1989 Jul;3(1):59-69
references.pmid: 2487092
references.citation: J Comp Neurol. 1990 Oct 22;300(4):593-606
references.pmid: 2273095
references.citation: Braz J Med Biol Res. 1989;22(1):121-38
references.pmid: 2758167
references.citation: J Comp Neurol. 1997 Oct 6;386(4):652-60
references.pmid: 9378858
references.citation: Cereb Cortex. 2007 Dec;17(12):2805-19
references.pmid: 17337746
references.citation: J Neurophysiol. 1986 Dec;56(6):1521-41
references.pmid: 3027273
references.citation: Neuroscience. 2005;133(1):193-207
references.pmid: 15893643
references.citation: Neuroscience. 1991;40(3):725-33
references.pmid: 1676494
references.citation: J Comp Neurol. 1946 Apr;84:221-75
references.pmid: 20982805
references.citation: J Comp Neurol. 2006 Jun 1;496(4):544-55
references.pmid: 16572432
references.citation: J Chem Neuroanat. 1999 Feb;16(2):77-116
references.pmid: 10223310
references.citation: J Comp Neurol. 2007 May 20;502(3):339-57
references.pmid: 17366604
references.citation: J Comp Neurol. 2000 Jul 17;423(1):140-77
references.pmid: 10861543
references.citation: J Comp Neurol. 2000 Jan 24;416(4):521-39
references.pmid: 10660882
references.citation: Behav Biol. 1978 Jan;22(1):1-22
references.pmid: 623604
references.citation: Neuroscience. 1995 Nov;69(1):71-81
references.pmid: 8637634
references.citation: Brain Behav Evol. 1980;17(6):432-53
references.pmid: 7437898
references.citation: J Comp Neurol. 1979 Feb 1;183(3):647-63
references.pmid: 103941
references.citation: Brain Res. 1994 Apr 11;642(1-2):267-80
references.pmid: 8032888
references.citation: Anat Rec (Hoboken). 2008 Oct;291(10):1301-33
references.pmid: 18780299
references.citation: Vision Res. 1988;28(12):1297-302
references.pmid: 3256146
references.citation: J Comp Neurol. 1984 Jul 1;226(3):391-402
references.pmid: 6611357
references.citation: J Comp Neurol. 1980 Sep 1;193(1):187-202
references.pmid: 6776164
references.citation: J Comp Neurol. 1975 Nov 1;164(1):79-94
references.pmid: 809494
references.citation: J Neurosci. 1990 Jan;10(1):73-90
references.pmid: 1688937
references.citation: Prog Brain Res. 2001;134:353-66
references.pmid: 11702554
references.citation: Brain Res Dev Brain Res. 1996 Oct 23;96(1-2):261-76
references.pmid: 8922688
references.citation: Cereb Cortex. 2001 Sep;11(9):849-67
references.pmid: 11532890
references.citation: J Comp Neurol. 1984 Feb 20;223(2):259-301
references.pmid: 6200520
references.citation: Biol Signals. 1994 May-Jun;3(3):127-39
references.pmid: 7531563
references.citation: J Neurosci. 1988 Dec;8(12):4653-61
references.pmid: 3199199
references.citation: J Comp Neurol. 1979 Jan 1;183(1):185-204
references.pmid: 102666
references.citation: J Neurosci. 1983 Aug;3(8):1648-69
references.pmid: 6875661
references.citation: Neurosci Biobehav Rev. 2001 Jul;25(5):395-407
references.pmid: 11566478
references.citation: Brain Res. 1986 Aug 6;379(2):329-41
references.pmid: 3742225
references.citation: Brain Res. 1991 Jan 11;538(2):351-7
references.pmid: 2012978
references.citation: Brain Behav Evol. 1972;6(1):457-83
references.pmid: 4122728
references.citation: J Comp Neurol. 1975 Feb 15;159(4):439-60
references.pmid: 1127139
references.citation: Mol Biol Evol. 2002 Jul;19(7):1053-65
references.pmid: 12082125
references.citation: Brain Res. 1974 Dec 20;82(1):173-7
references.pmid: 4611594
references.citation: Adv Exp Med Biol. 1986;203:83-98
references.pmid: 2431606
references.citation: J Comp Neurol. 1977 May 15;173(2):389-416
references.pmid: 853144
references.citation: Nature. 2001 May 10;411(6834):141-2
references.pmid: 11346770
references.citation: Eur J Neurosci. 1989 May;1(3):222-246
references.pmid: 12106154
references.citation: J Comp Neurol. 1990 Aug 1;298(1):1-22
references.pmid: 2170466
references.citation: Science. 2003 Mar 7;299(5612):1568-72
references.pmid: 12595609
references.citation: J Comp Neurol. 1972 Jul;145(3):273-305
references.pmid: 5030907
references.citation: J Comp Neurol. 1987 Aug 1;262(1):27-45
references.pmid: 2442207
references.citation: J Comp Neurol. 1992 Sep 8;323(2):167-97
references.pmid: 1401255
references.citation: Eur J Neurosci. 2000 Jul;12(7):2425-51
references.pmid: 10947821
references.citation: Behav Brain Res. 2003 Nov 30;146(1-2):3-17
references.pmid: 14643455
references.citation: J Comp Neurol. 2004 Mar 22;471(1):97-111
references.pmid: 14983479
references.citation: J Neurosci. 2003 Feb 15;23(4):1372-82
references.pmid: 12598625
references.citation: Brain Res Rev. 2007 Oct;55(2):285-96
references.pmid: 17433837
references.citation: J Comp Neurol. 1989 Sep 1;287(1):38-63
references.pmid: 2477399
references.citation: Brain Res. 1977 Feb 11;122(1):15-31
references.pmid: 837217
references.citation: Neuroscience. 1988 Feb;24(2):379-431
references.pmid: 2452377
references.citation: J Comp Neurol. 1977 Jan 15;171(2):157-91
references.pmid: 64477
references.citation: J Comp Neurol. 1992 Dec 15;326(3):451-69
references.pmid: 1334980
references.citation: J Comp Neurol. 2000 Apr 10;419(3):306-19
references.pmid: 10723007
references.citation: J Comp Neurol. 1996 Nov 11;375(2):274-88
references.pmid: 8915830
references.citation: J Histochem Cytochem. 2005 Feb;53(2):141-53
references.pmid: 15684327
references.citation: Proc Natl Acad Sci U S A. 2004 Feb 17;101(7):2167-72
references.pmid: 14766982
references.citation: Proc Natl Acad Sci U S A. 1988 Mar;85(6):1998-2002
references.pmid: 2450354
references.citation: Neurosci Res. 1990 Apr;8(1):40-7
references.pmid: 2163048
references.citation: J Comp Neurol. 1983 Dec 10;221(3):329-40
references.pmid: 6655087
references.citation: Brain Res. 1983 May 16;267(2):201-16
references.pmid: 6871673
references.citation: Brain Res. 1979 Jul 27;171(1):11-28
references.pmid: 223730
references.citation: J Comp Neurol. 2005 Apr 18;484(4):458-73
references.pmid: 15770654
references.citation: Neuroscience. 2001;105(3):553-69
references.pmid: 11516823
references.citation: J Comp Neurol. 1998 Oct 26;400(3):349-62
references.pmid: 9779940
references.citation: Brain Res. 1984 Feb 6;292(2):251-60
references.pmid: 6692158
references.citation: Neuroscience. 1990;36(1):165-74
references.pmid: 1977100
references.citation: Brain Res. 1971 Dec 10;35(1):89-106
references.pmid: 5002564
references.citation: Neuroimage. 2004 Jan;21(1):15-26
references.pmid: 14741638
references.citation: Trends Neurosci. 1999 Jun;22(6):242-8
references.pmid: 10354599
references.citation: Exp Brain Res. 1994;100(1):67-84
references.pmid: 7813654
references.citation: J Comp Neurol. 1986 Aug 22;250(4):403-30
references.pmid: 3760247
references.citation: J Comp Neurol. 1983 Jul 10;217(4):390-404
references.pmid: 6886060
references.citation: Brain Res. 1982 Jul;256(3):275-84
references.pmid: 6179578