TITLE:
Cortical columns (barrels) display normal size in the brain’s primary somatosensory cortex of mice carrying null mutations of the insulin receptor substrate 1 gene: A preliminary report
AUTHORS:
Marta López-Santibáñez Guevara, Eileen Uribe-Querol, Alma Lilia Fuentes Farías, Esperanza Meléndez-Herrera, Agustine Joseph D’Ercole, Gabriel Gutiérrez-Ospina
KEYWORDS:
Barrel Cortex; Neuronal Circuit Assemblage; Trophic Interactions; Constructivism
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.4 No.10,
October
18,
2013
ABSTRACT: Circuits in barrels of the rodent brain’s primary somatosensory
(S1) cortex build up following constructivist rules. Previous evidence in
mice supports that the precise addition of barrel neuropil is promoted by
insulin-like growth factor-1 (IGF-1). The signaling cascades mediating this
response remain undetermined. To address
whether the effects of IGF-1 upon the growth of S1 circuits are
mediated by insulin receptor substrate-1 (IRS-1), we studied barrel size in
adult mice having the IRS-1 gene knocked out (IRS-1 ko). Our results reveal
that barrel size is similar between wild type and IRS-1 ko mice suggesting
that IRS-1 is not essential for barrel circuitry growth. Hence, investigations
aimed at exploring other substrates activated by IGF-1, namely IRS-2 and
IRS-4, are needed to reveal signaling pathways that mediate the precise
addition of S1 neuronal circuitry.