title: Mild prenatal protein malnutrition increases alpha2C-adrenoceptor density in the cerebral cortex during postnatal life and impairs neocortical long-term potentiation and visuo-spatial performance in rats.
abstract: Mild reduction in the protein content of the mother's diet from 25 to 8% casein, calorically compensated by carbohydrates, does not alter body and brain weights of rat pups at birth, but leads to significant enhancements in the concentration and release of cortical noradrenaline during early postnatal life. Since central noradrenaline and some of its receptors are critically involved in long-term potentiation (LTP) and memory formation, this study evaluated the effect of mild prenatal protein malnutrition on the alpha2C-adrenoceptor density in the frontal and occipital cortices, induction of LTP in the same cortical regions and the visuo-spatial memory. Pups born from rats fed a 25% casein diet throughout pregnancy served as controls. At day 8 of postnatal age, prenatally malnourished rats showed a threefold increase in neocortical alpha2C-adrenoceptor density. At 60 days-of-age, alpha2C-adrenoceptor density was still elevated in the neocortex, and the animals were unable to maintain neocortical LTP and presented lower visuo-spatial memory performance. Results suggest that overexpression of neocortical alpha2C-adrenoceptors during postnatal life, subsequent to mild prenatal protein malnutrition, could functionally affect the synaptic networks subserving neocortical LTP and visuo-spatial memory formation.
authors.affiliation: Institute of Nutrition and Food Technology, University of Chile, Santiago, Chile. rsoto@inta.cl
authors.forename: Rubén
authors.initials: R
authors.lastname: Soto-Moyano
authors.forename: Luis
authors.initials: L
authors.lastname: Valladares
authors.forename: Walter
authors.initials: W
authors.lastname: Sierralta
authors.forename: Hernán
authors.initials: H
authors.lastname: Pérez
authors.forename: Mauricio
authors.initials: M
authors.lastname: Mondaca
authors.forename: Victor
authors.initials: V
authors.lastname: Fernández
authors.forename: Héctor
authors.initials: H
authors.lastname: Burgos
authors.forename: Alejandro
authors.initials: A
authors.lastname: Hernández
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002540:Cerebral Cortex / Q000378:metabolism*; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D017774:Long-Term Potentiation; D044342:Malnutrition / Q000378:metabolism*; D008568:Memory; D019579:Neocortex / Q000503:physiopathology; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D020033:Protein Isoforms / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018341:Receptors, Adrenergic, alpha-2 / Q000378:metabolism*; D013028:Space Perception; D014796:Visual Perception
chemical_list: D004044:Dietary Proteins; D020033:Protein Isoforms; D018341:Receptors, Adrenergic, alpha-2