BACKGROUND: Williams syndrome (WMS) is a rare, genetically based syndrome associated with a hemideletion in chromosome 7 (7q11.22-23) and characterized by a unique constellation of somatic, brain, and cognitive features. Individuals with WMS demonstrate an unusual and uneven neuropsychological profile showing cognitive and visual spatial deficits juxtaposed with relative language preservation and excellent facial recognition. OBJECTIVES: A neuroanatomical hypothesis for these behavioral findings suggests predominant involvement of the dorsal portions of the hemispheres relative to the ventral portions, including preferential involvement of peripheral visual field cortical representations over central representation. Predominant involvement of magnocellular visual pathways, as opposed to parvocellular pathways, is also suggested by this hypothesis. SUBJECTS: We examined primary visual cortical area 17 in the right and left hemispheres in 6 age- and sex-matched autopsy specimens from 3 WMS-affected brains (1 male and 2 females; mean [SD] age, 44 [14] years) and 3 control brains (1 male and 2 females; mean age, 43 [11] years). DESIGN: Neurons in layers II, III, IVA, IVB, IVCalpha, IVCbeta, V, and VI were measured using an optical dissector method to determine possible differences between WMS-affected and control brains in cell-packing density, neuronal size, and neuronal size distribution. RESULTS: We found abnormalities in peripheral visual cortex in WMS-affected brains, but not in magnocellular subdivisions. There was a hemisphere by layer IV interaction and a layer IV left hemisphere and diagnosis interaction in cell-packing density. Williams syndrome-affected brains showed increased cell-packing density in left sublayer IVCbeta and an excess of small neurons in left layers IVA, IVCalpha, IVCbeta, V, and VI. CONCLUSIONS: Cell measurements differ in peripheral visual cortical fields of WMS, with significantly smaller, more closely packed cells in some layers on the left side. These cell-packing density and neuronal size differences may be related to visuospatial deficits in this population.
BACKGROUND:Williams syndrome (WMS) is a rare, genetically based syndrome associated with a hemideletion in chromosome 7 (7q11.22-23) and characterized by a unique constellation of somatic, brain, and cognitive features. Individuals with WMS demonstrate an unusual and uneven neuropsychological profile showing cognitive and visual spatial deficits juxtaposed with relative language preservation and excellent facial recognition. OBJECTIVES: A neuroanatomical hypothesis for these behavioral findings suggests predominant involvement of the dorsal portions of the hemispheres relative to the ventral portions, including preferential involvement of peripheral visual field cortical representations over central representation. Predominant involvement of magnocellular visual pathways, as opposed to parvocellular pathways, is also suggested by this hypothesis. SUBJECTS: We examined primary visual cortical area 17 in the right and left hemispheres in 6 age- and sex-matched autopsy specimens from 3 WMS-affected brains (1 male and 2 females; mean [SD] age, 44 [14] years) and 3 control brains (1 male and 2 females; mean age, 43 [11] years). DESIGN: Neurons in layers II, III, IVA, IVB, IVCalpha, IVCbeta, V, and VI were measured using an optical dissector method to determine possible differences between WMS-affected and control brains in cell-packing density, neuronal size, and neuronal size distribution. RESULTS: We found abnormalities in peripheral visual cortex in WMS-affected brains, but not in magnocellular subdivisions. There was a hemisphere by layer IV interaction and a layer IV left hemisphere and diagnosis interaction in cell-packing density. Williams syndrome-affected brains showed increased cell-packing density in left sublayer IVCbeta and an excess of small neurons in left layers IVA, IVCalpha, IVCbeta, V, and VI. CONCLUSIONS: Cell measurements differ in peripheral visual cortical fields of WMS, with significantly smaller, more closely packed cells in some layers on the left side. These cell-packing density and neuronal size differences may be related to visuospatial deficits in this population.
Authors: Eileen Luders; Margherita Di Paola; Francesco Tomaiuolo; Paul M Thompson; Arthur W Toga; Stefano Vicari; Michael Petrides; Carlo Caltagirone Journal: Neuroreport Date: 2007-02-12 Impact factor: 1.837
Authors: Anna Järvinen-Pasley; Ralph Adolphs; Anna Yam; Kiley J Hill; Mark Grichanik; Judy Reilly; Debra Mills; Allan L Reiss; Julie R Korenberg; Ursula Bellugi Journal: Neuropsychologia Date: 2010-04-10 Impact factor: 3.139
Authors: Andrew T N Tebbenkamp; Luis Varela; Jinmyung Choi; Miguel I Paredes; Alice M Giani; Jae Eun Song; Matija Sestan-Pesa; Daniel Franjic; André M M Sousa; Zhong-Wu Liu; Mingfeng Li; Candace Bichsel; Marco Koch; Klara Szigeti-Buck; Fuchen Liu; Zhuo Li; Yuka I Kawasawa; Constantinos D Paspalas; Yann S Mineur; Paolo Prontera; Giuseppe Merla; Marina R Picciotto; Amy F T Arnsten; Tamas L Horvath; Nenad Sestan Journal: Cell Date: 2018-11-01 Impact factor: 41.582
Authors: D L Mills; L Dai; I Fishman; A Yam; L G Appelbaum; M St George; A Galaburda; U Bellugi; J R Korenberg Journal: Dev Neuropsychol Date: 2013 Impact factor: 2.253
Authors: Anna Järvinen-Pasley; Ursula Bellugi; Judy Reilly; Debra L Mills; Albert Galaburda; Allan L Reiss; Julie R Korenberg Journal: Dev Psychopathol Date: 2008