alexa Prenatal protein restriction alters synaptic mechanisms of callosal connections in the rat visual cortex.


Brain Disorders & Therapy

Author(s): SotoMoyano R, Alarcn S, Belmar J, Kusch C, Prez H,

Abstract Share this page

Abstract Mild prenatal protein malnutrition, induced by reduction of the casein content of the maternal diet from 25 to 8\%, calorically compensated by the addition of excess carbohydrates, leads to so-called "hidden" malnutrition in the rat. This form of malnutrition results in normal body and brain weights of pups at birth, but in significant alterations of their central nervous system neurochemical profiles. Since severe forms of prenatal malnutrition induce morpho-functional deficits on callosal interhemispheric communication together with brain neurochemical disturbances, we evaluated, in rats born from mothers submitted to an 8\% casein diet, the potassium-induced release of [3H]-noradrenaline in visual cortex slices, as well as functional properties of callosal-cortical synapses by determining cerebral cortical excitability to callosal inputs and fatigability and temporal summation of transcallosal evoked responses. Rats born from mothers submitted to a 25\% casein diet served as controls. At birth prenatally malnourished pups had significantly higher cortical percent net noradrenaline release (14.79 +/- 1.11) than controls (9.14 +/- 1.26). At 45-50 days of age, rehabilitated previously malnourished rats showed, when compared to controls; (i) significantly reduced percent net noradrenaline release in the visual cortex (4.50 +/- 0.52 vs 11.31 +/- 1.14); (ii) decreased cortical excitability to callosal inputs as revealed by significantly increased chronaxie (607.2 +/- 82.8 microseconds vs 351.3 +/- 47.7 microseconds); (iii) enhanced fatigability of transcallosal evoked responses as revealed by significantly decreased stimulus frequency required to fatigate the responses (4.9 +/- 0.8 Hz vs 9.2 +/- 1.3 Hz); and (iv) decreased ability of callosal-cortical synapses to perform temporal summation, as revealed by significantly reduced percent response increment to double-shock (54.2 +/- 6.2 vs 83.0 +/- 11.0, for a 3.2-ms interstimulus time interval). These changes, resulting from mild prenatal protein restriction, are discussed in relationship to developmental processes leading to the formation of synaptic contacts between callosal axons and their appropriate cortical target during perinatal age.
This article was published in Int J Dev Neurosci and referenced in Brain Disorders & Therapy

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version