Cortical area size dictates performance at modality-specific behaviors

TY - JOUR

T1 - Cortical area size dictates performance at modality-specific behaviors

AU - Leingärtner, Axel

AU - Thuret, Sandrine

AU - Kroll, Todd T

AU - Chou, Shen-Ju

AU - Leasure, J Leigh

AU - Gage, Fred H

AU - O'Leary, Dennis D M

PY - 2007/3/6

Y1 - 2007/3/6

N2 - The mammalian neocortex is organized into unique areas that serve functions such as sensory perception and modality-specific behaviors. The sizes of primary cortical areas vary across species, and also within a species, raising the question of whether area size dictates behavioral performance. We show that adult mice genetically engineered to overexpress the transcription factor EMX2 in embryonic cortical progenitor cells, resulting in reductions in sizes of somatosensory and motor areas, exhibit significant deficiencies at tactile and motor behaviors. Even increasing the size of sensorimotor areas by decreasing cortical EMX2 levels can lead to diminished sensorimotor behaviors. Genetic crosses that retain ectopic Emx2 transgene expression subcortically but restore cortical Emx2 expression to wild-type levels also restore cortical areas to wild-type sizes and in parallel restore tactile and motor behaviors to wild-type performance. These findings show that area size can dictate performance at modality-specific behaviors and suggest that areas have an optimal size, influenced by parameters of its neural system, for maximum behavioral performance. This study underscores the importance of establishing during embryonic development appropriate levels of regulatory proteins that determine area sizes, thereby influencing behavior later in life.

AB - The mammalian neocortex is organized into unique areas that serve functions such as sensory perception and modality-specific behaviors. The sizes of primary cortical areas vary across species, and also within a species, raising the question of whether area size dictates behavioral performance. We show that adult mice genetically engineered to overexpress the transcription factor EMX2 in embryonic cortical progenitor cells, resulting in reductions in sizes of somatosensory and motor areas, exhibit significant deficiencies at tactile and motor behaviors. Even increasing the size of sensorimotor areas by decreasing cortical EMX2 levels can lead to diminished sensorimotor behaviors. Genetic crosses that retain ectopic Emx2 transgene expression subcortically but restore cortical Emx2 expression to wild-type levels also restore cortical areas to wild-type sizes and in parallel restore tactile and motor behaviors to wild-type performance. These findings show that area size can dictate performance at modality-specific behaviors and suggest that areas have an optimal size, influenced by parameters of its neural system, for maximum behavioral performance. This study underscores the importance of establishing during embryonic development appropriate levels of regulatory proteins that determine area sizes, thereby influencing behavior later in life.

KW - Animals

KW - Behavior, Animal

KW - Body Weight

KW - Brain

KW - Brain Mapping

KW - Genotype

KW - Heterozygote

KW - Mice

KW - Mice, Knockout

KW - Mice, Transgenic

KW - Models, Anatomic

KW - Models, Genetic

KW - Motor Neurons

KW - Neocortex

U2 - 10.1073/pnas.0611723104

DO - 10.1073/pnas.0611723104

M3 - SCORING: Journal article

C2 - 17360492

VL - 104

SP - 4153

EP - 4158

JO - P NATL ACAD SCI USA

JF - P NATL ACAD SCI USA

SN - 0027-8424

IS - 10

ER -