Dietary iron absorption during early postnatal life

BioMetals ◽  
2019 ◽  
Vol 32 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Sheridan L. Helman ◽  
Gregory J. Anderson ◽  
David M. Frazer
Keyword(s):  
Iron Absorption ◽  
Postnatal Life ◽  
Dietary Iron ◽  
Early Postnatal Life

Regulation of motor neuron dendrite growth by NMDA receptor activation

Development ◽  
1994 ◽  
Vol 120 (11) ◽  
pp. 3063-3071 ◽  
Author(s):  
R.G. Kalb
Keyword(s):  
Nmda Receptor ◽  
Motor Neuron ◽  
Cell Body ◽  
Motor Neurons ◽  
Receptor Activation ◽  
Dendrite Growth ◽  
Postnatal Life ◽  
Receptor Antagonism ◽  
Neuron Cell Body ◽  
Early Postnatal Life

Spinal motor neurons undergo great changes in morphology, electrophysiology and molecular composition during development. Some of this maturation occurs postnatally when limbs are employed for locomotion, suggesting that neuronal activity may influence motor neuron development. To identify features of motor neurons that might be regulated by activity we first examined the structural development of the rat motor neuron cell body and dendritic tree labeled with cholera toxin-conjugated horseradish peroxidase. The motor neuron cell body and dendrites in the radial and rostrocaudal axes grew progressively over the first month of life. In contrast, the growth of the dendritic arbor/cell and number of dendritic branches was biphasic with overabundant growth followed by regression until the adult pattern was achieved. We next examined the influence of neurotransmission on the development of these motor neuron features. We found that antagonism of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor inhibited cell body growth and dendritic branching in early postnatal life but had no effect on the maximal extent of dendrite growth in the radial and rostrocaudal axes. The effects of NMDA receptor antagonism on motor neurons and their dendrites was temporally restricted; all of our anatomic measures of dendrite structure were resistant to NMDA receptor antagonism in adults. These results suggest that the establishment of mature motor neuron dendritic architecture results in part from dendrite growth in response to afferent input during a sensitive period in early postnatal life.

scholarly journals A STEREOLOGICAL ANALYSIS OF THE EFFECT OF EARLY POSTNATAL ETHANOL EXPOSURE ON NEURONAL NUMBERS IN RAT DENTATE GYRUS

2011 ◽  
Vol 19 (2) ◽  
pp. 99 ◽  
Author(s):  
Takanori Miki ◽  
Simon J Harris ◽  
Peter Wilce ◽  
Yoshiki Takeuchi ◽  
Kuldip S Bedi
Keyword(s):  
Dentate Gyrus ◽  
Hippocampal Formation ◽  
Ethanol Exposure ◽  
Learning Ability ◽  
Ethanol Ingestion ◽  
High Dose ◽  
Postnatal Life ◽  
Numerical Density ◽  
Rat Pups ◽  
Early Postnatal Life

Maternal ethanol ingestion during pregnancy can cause fetal alcohol syndrome (FAS) in their offspring. Among the symptoms of FAS, damage to the central nervous system has emerged as one of the most serious problems. We have previously shown that a relatively high dose of ethanol exposure during early postnatal life can cause alterations in spatial learning ability. This ability is controlled, at least in part, by the hippocampal formation. The purpose of the present study was to determine whether exposure of rat pups to ethanol during early postnatal life had effects on the total number of the dentate gyrus neurons. Wistar rats were exposed to a relatively high daily dose of ethanol between postnatal days 10 to 15. Ethanol exposure was achieved by placing rat pups in a chamber containing ethanol vapour for 3 hours a day. The blood ethanol concentration was found to be about 430 mg/dL at the end of the exposure period. Groups of ethanol treated (ET), separation controls (SC) and mother reared controls (MRC) were anaesthetised and killed at 16-days-of-age by perfusion with phosphate-buffered 2.5% glutaraldehyde. The Cavalieri principle was used to determine the volume of subdivisions of the dentate gyrus, and the physical disector method was used to estimate the numerical densities of neurons within each subdivision. The total number of neurons was calculated by multiplying estimates of the numerical density with the volume. There was, on average, about 421,000 granule cells in all three treatment groups. In the hilus region, ET rats had about 27,000 neuronal cells. This value was significantly smaller than the average of 38,000 such neurons estimated to be present in both MRC and SC animals. It is concluded that neurons in the hilus region of the dentate gyrus may be particularly vulnerable to the effects of a high dose of ethanol exposure during PND 10-15. It is likely that this deficit was due to neuronal death induced by some mechanisms related to the ethanol exposure.

scholarly journals Leptin levels at birth and in early postnatal life in small- and appropriate-for-gestational-age infants

Medicina ◽  
2007 ◽  
Vol 43 (10) ◽  
pp. 784 ◽  
Author(s):  
Margarita Valūnienė ◽  
Rasa Verkauskienė ◽  
Margaret Boguszewski ◽  
Jovanna Dahlgren ◽  
Danutė Lašienė ◽  
...  
Keyword(s):  
Birth Weight ◽  
Gestational Age ◽  
Small For Gestational Age ◽  
Venous Blood ◽  
Postnatal Life ◽  
Abrupt Decrease ◽  
Blood Samples ◽  
Appropriate For Gestational Age ◽  
Early Postnatal Life ◽  
The Impact

The aim of this study was to evaluate leptin concentration at birth and in early postnatal life in small- and appropriate-for-gestational-age infants and to assess its relationship with infants’ anthropometry at birth and some characteristics of maternal pregnancy. Materials and methods. A total of 367 infants born after 32–42 weeks of gestation were enrolled in the study. Umbilical cord blood samples were collected from 80 small- and 287 appropriate- for-gestational-age newborns. Altogether, 166 venous blood samples were taken from these neonates on days 2–6 of life. Results. Cord leptin levels were significantly lower in small- compared to appropriate-forgestational- age infants. We observed a positive correlation between cord leptin and birth weight, all neonatal anthropometric parameters, placental weight, and some maternal nutritional factors. In multivariate analysis, cord leptin concentration explained up to 15% of the variation in sum of newborn’s skinfold thickness but only 5% of the variation in birth weight. Postnatally, leptin concentration decreased markedly to the similar low levels in both infant groups and remained so during the first postnatal week. Conclusions. Significantly lower cord leptin concentration in small-for-gestational-age neonates reflects a lower fat mass content compared to appropriate-for-gestational-age infants. However, an abrupt decrease in leptin levels shortly after birth in both groups suggests that placenta could be an important source of leptin in fetal circulation. The impact of low leptin levels at birth in small-for-gestational-age infants on their postnatal appetite and weight gain remains to be elucidated in future studies.

Sign in / Sign up

Export Citation Format

Share Document