Hadronic Vacuum Polarization Contribution to the Anomalous Magnetic Moments of Leptons from First Principles.

We compute the leading, strong-interaction contribution to the anomalous magnetic moment of the electron, muon, and tau using lattice quantum chromodynamics (QCD) simulations. Calculations include the effects of u, d, s, and c quarks and are performed directly at the physical values of the quark masses and in volumes of linear extent larger than 6 fm. All connected and disconnected Wick contractions are calculated. Continuum limits are carried out using six lattice spacings. We obtain a_{e}^{LO-HVP}=189.3(2.6)(5.6)×10^{-14}, a_{µ}^{LO-HVP}=711.1(7.5)(17.4)×10^{-10} and a_{τ}^{LO-HVP}=341.0(0.8)(3.2)×10^{-8}, where the first error is statistical and the second is systematic.

Lattice Computation of the Nucleon Scalar Quark Contents at the Physical Point.

We present a QCD calculation of the u, d, and s scalar quark contents of nucleons based on 47 lattice ensembles with N_{f}=2+1 dynamical sea quarks, 5 lattice spacings down to 0.054 fm, lattice sizes up to 6 fm, and pion masses down to 120 MeV. Using the Feynman-Hellmann theorem, we obtain f_{ud}^{N}=0.0405(40)(35) and f_{s}^{N}=0.113(45)(40), which translates into σ_{πN}=38(3)(3) MeV, σ_{sN}=105(41)(37) MeV, and y_{N}=0.20(8)(8) for the sigma terms and the related ratio, where the first errors are statistical and the second errors are systematic. Using isospin relations, we also compute the individual up and down quark contents of the proton and neutron (results in the main text).

Movements restriction and alterations of the number of spines distributed along the apical shafts of layer V pyramids in motor and primary sensory cortices of the peripubertal and adult rat.

The number and distribution of spines along apical shafts of rapid-Golgi-stained layer V pyramidal cells from visual, motor and somatosensory cortical areas were analyzed in control and movement-restricted (beginning at 20 days old) Wistar rats killed at 30, 40, 80 and 120 days of age (experiment A). In other group of rats, spine density was analyzed when restriction initiates on day 40 and the animals were killed at 50, 60 and 80 days postpartum, or after restriction starting on day 80 and killed at 120 days of age (experiment B). It has been found that the restriction of movements significantly reduces the total number of spines on apical shafts in the three cortical areas, when this condition starts at 20, 40 or 80 days without changing the overall distribution of spines. Also present findings indicate that the effects of movements restriction are attenuated when they were concurrent with maturational brain processes (20-40 days) than when they occurred later in life. The question remains open of which part of the measured reduction on the number of spines is due to the immobilization and which to the stress associated with this maneuver.

Neonatal food restriction induces hypoplasia in developing facial motor neurons of rats.

The effects of neonatal food restriction upon the dendritic development of facial nucleus (FN) motor neurons of Wistar rats were analyzed. Rats neonatally underfed by daily (12 h) mother-litter separation in an incubator from 5-30 days after birth exhibited, in brain stem Golgi-Cox sections, significant reductions in the number and extension of stellate, triangular and bipolar FN neuronal dendritic prolongations with negligible effects upon perikarya measurements. Data suggest that in the underfed newborn, the ability of FN neurons to establish synaptic contacts with afferent fibers is reduced, which then interferes with their capacities for the integration and triggering of nerve impulses to modulate facial motor expression in response to sensory cues.

Effects of perinatal undernourishment on neuronal development of the facial motor nucleus in the rat.

The facial nucleus (FN) of the rat is composed of multipolar neurons generated between gestational days G12 and G15. This nucleus is involved in the mechanisms underlying muscle contraction during the sucking reflex. After birth, the neuronal substrate of this reflex is gradually organized to allow the performance of other functions such as gnawing, chewing, swallowing and drinking. Undernourishment is known to produce different degrees of delayed brain development, the greatest of which are similar to the characteristics of the premature syndrome. Neuronal morphological alterations are associated with sucking-reflex deficiencies, which interfere with feeding by the newborn. The current study shows that perinatal undernourishment leads to dendritic arbor hypoplasia and small alterations of soma size in Golgi--Cox impregnated FN neurons of rats. The data suggest that these morphological alterations of FN neurons, may be associated with shifts in the input and integration of signals, and may finally modify the elaboration of motoneuron discharges partly modulating bucolabial muscle contraction during sucking movements and facial expression. Additionally, neonatal nutritional rehabilitation modifies the effects on FN neuronal development, ameliorating the influence of early adverse nutritional conditions.

Recovery of long-term maternal behavioral deficiencies of neonatally underfed rats by early sensory stimulation: effects of successive parturitions.

The study examines the effects of two paradigms of neonatal food deprivation (daily mother-litter separation, Experiment 1 or nipple-ligation of mothers, Experiment 2) associated or not to early sensory stimulation (daily handling or the exposure to an enriched sensory environment) during the pre-weaning period of Wistar strain female rats. The effects of experimental manipulations were evaluated by measuring the nest building, retrieving latencies and nursing time of adult dams along three successive parturitions. Undernourished dams of Experiment 1, showed significant alterations in maternal responsiveness in the first delivery, which were attenuated by the maternal experience of two additional parturitions. Moreover, maternal alterations were importantly compensated by the association to early sensory stimulation (except nest building). Underfed mothers of Experiment 2 exhibited less alterations of the maternal response during the first parturition, and these were ameliorated by the maternal experience of successive parturitions. Additionally, complete recovery of maternal responsiveness alterations was obtained when sensory stimulation was associated to the maternal experience. Data suggest differential vulnerability to neonatal food and sensory deprivation of the neural mechanisms underlying maternal performance.

Development of play behavior in neonatally undernourished rats.

The effects of neonatal food and sensory deprivation on play social behavior (boxing, wrestling, and pinning) were studied in male and female Wistar strain rats from 20 to 60 days of age. Data showed that the mean frequency of total play was markedly increased in neonatally underfed subjects. Play did also increase in the females and during the interaction in pairs and in the play that occurred during the prepuberal period. These findings suggest that early food restriction and the unavoidable sensory deprivation associated to the undernourishing procedure, interfere with the neuroendocrine maturational processes of central and peripheral modulatory mechanisms underlying play behavior.

Effects of neonatal undernutrition and binaural ear occlusion on neuronal development of the superior olivary complex of rats.

Golgi-Cox-impregnated neurons of the superior olivary complex were investigated in control, binaural ear-occluded control, undernourished, and binaural ear-occluded undernourished Wistar rats of 12, 20, and 30 days of age. In neonatally undernourished and binaural ear-occluded animals, a significant reduction in the number of dendrites and dendritic intersections in the medial trapezoid body neurons was observed. Inconsistent effects upon the dendritic arbor lateral superior olivary cells were also detected. Control and undernourished rats with binaural ear occlusion exhibited a significant increase in the dendritic arbor measurements of lateral superior olivary neurons as compared with the cells of the medial trapezoid body. The cytoarchitectonic imbalance between the modulatory efferent control of these systems and the sensory auditory input to the cochlea may be important for the integration of complex auditory physiological phenomena.

Maternal Responsiveness of Neonatally Undernourished and Sensory Stimulated Rats: Rehabilitation of Maternal Behavior.

The interaction between neonatal food deprivation and early sensory stimulation on four maternal behavioral components of Wistar strain rats was investigated. Dams neonatally underfed by daily mother-litter separation (Experiment 1), showed significant reductions in nest-rating and nursing time as well as increased retrieving latencies and selfgrooming responses compared to controls. Mothers which were neonatally undernourished by the nipple-ligation of their mothers (Experiment 2), exhibited less alterations in nest ratings, nursing time and retrieving latencies with no significant differences in the frequency of self-grooming responses, in comparison to controls. Neonatal handling and the exposure to a sensory enriched environment in Experiment 1, ameliorated most of the alterations of neonatally underfed mothers. Moreover, in Experiment 2, the increase in the neonatal sensory stimulation only improves nest ratings performance without consistent effects upon other maternal behavioral responses. Data suggest that sensory stimulation at critical stages of brain ontogeny is able to compensate long-term maternal behavioral deficiencies associated to a severe neonatal undernutrition (Experiment 1), with variable effects following a mild food intake deprivation (Experiment 2).

The hindlimb hyperextension associated to the urogenital response in newborn underfed rats.

BACKGROUND: The aim of the study was to investigate how neonatal undernutrition interacts with mother-infant relationships to interfere with the expression of the urogenital response in the newborn. METHODS: The hyperextensive reflex components associated to the urogenital response (HUR) were measured between postnatal days 1-21, in control and neonatally undernourished rats with or without fullness of the bladder. RESULTS: In Experiment 1, both male and female underfed rats with different degrees of bladder fullness exhibited an increment in HUR latency and vertical hindlimb displacement, reduced transversal separation and prolonged performance of hindlimb relaxation. Experiment 2 was performed in rats after urine elicitation provoked only reduced hindlimb transversal separation in males, and prolonged latency to HUR in females. DISCUSSION: These findings may be related to the vulnerability to neonatal undernutrition of the maturational processes which take place in the spinal cord, the condition of the bladder, and hindleg muscle maturation during this period of life. CONCLUSIONS: Data suggest that neonatal undernutrition may play a role in mother-infant interaction by interfering with HUR responses to maternal anogenital licking of the pups.

Swimming and self-grooming development of pups nursed by neonatally underfed rats.

Swimming and self-grooming development were analyzed in experimental animals nursed by neonatally underfed dams by a method including the deprivation of both food and sensory cues which provoke long-term altered maternal behavior. Experimental animals obtained from these dams manifested a significant retardation in physical growth, as evidenced by a decrease in body weight and a 1-day delay in ear and eye-opening, as well as a significant delay in swimming ability, escaping from the water and an increase in self-grooming behavior. These alterations of experimental animals may be presumably related with the carelessness in maternal care and altered so-matosensory stimulation given by the neonatally underfed dams to her experimental pups. Data suggest that the poor somatosensory stimulation given by the mother to her pups, the reduced early social interaction or the motivational stage of pups may be important determinants for the development of brain mechanisms underlying reflex activity of the progeny.

Hair growth in neonatally undernourished rats.

Interaction between neonatal undernutrition and the increased self-grooming activity upon hair growth of several body areas was analyzed in rats of 10, 20 and 30 days of age. Light microscopic observations on methylene blue impregnated hairs showed that these perinatal influences delayed the growth of hair follicles and thickness and length of hair measurements of the head and thoracic areas. The hair growth of lateral abdominal regions was less affected. Data suggest that hair alterations are primarily related to food deprivation since hair follicle measures of all skin areas were more affected than the distal hair measurements. Moreover, the distribution of impaired hair growth on different body areas correlates well with the increased self-grooming components associated to neonatal undernourishment.

Dendritic arbor alterations in the medial superior olivary neurons of neonatally underfed rats.

Golgi-Cox-stained bipolar cells of the medial superior olive (MSO) were analyzed in control and undernourished Wistar strain rats at 12, 20, 30 and 40 days of age. Undernutrition significantly reduced the number of dendrites and the extension of ipsilateral dendritic prolongations, with no effects upon the cross-sectional somal area and minimal alterations in the corresponding contralateral dendritic branches. The data suggest that in underfed rate, afferents from the receptors projecting to the MSO via the anteroventral cochlear nuclei may cause an imblance in the binaural interactions which occur between the axon terminals and the ipsilateral contralateral dendritic arbors of MSO neurons.

Alterations in the thalamic reticular nucleus of rats neonatally treated with thyroxine.

Golgi-Cox impregnated loci of the thalamic reticular nucleus (TRN) of normal and neonatally T4-treated Wistar strain rats at 12, 20 and 30 days of age were analyzed. In a total of 120 TRN camera lucida drawings. The number of visible neurons, the area and the maximal transverse TRN length were quantitated. T4-treated rats showed a significant increase in the number of neurons at 12 days of age, followed by significant reductions of this parameter at 20 and 30 days old. By contrast the area of TRN hyperthyroid rats showed significant reductions on days 20 and 30 postnatally, and the maximal transverse length of the same group of rats showed a consistent significant reduction only at 30 days postpartum. The data are partly in line with previous studies showing an initial accelerated brain maturation, followed by a subsequent neuronal retardation, although the area and the maximal transverse TRN length measurements did not exhibit this sequence of development. The findings suggest that neonatal T4-treatment may interfere with the TRN morphological organization, and the modulatory actions upon the thalamic sensory transmission.

Neonatal undernutrition and self-grooming development in the rat: long-term effects.

The effect of neonatal undernutrition on six different self-grooming components was examined in male rats during the pre- and postweaning periods. Rats underfed by the maternal nipple-ligation procedure before weaning did not exhibit significant score differences in the various self-grooming measurements. In contrast, after weaning they showed a significant increment in the duration of face-washing, head-washing, fur licking and body-scratching. In all cases, the total postweaning self-grooming activity was significantly increased in the formerly underfed rats. Present data suggest that neonatal undernutrition may presumably interfere with the sequential maturational processes of central and/or peripheral mechanisms underlying some components of self-grooming behavior.

Nutrition and undernutrition in the valley of Mexico: possible transgenerational influences.

The dietary quality of several generations of inhabitants living in the Valley of Mexico City, was examined on the light of recent information obtained from experimental undernutrition studies. Socioeconomic status and environmental limitations were also considered. This essay proposes that some transgenerational effects described in animal models, such as the diminished brain and body weight, the low cerebral DNA content, the hypermotility and some learning disabilities could have equivalents in the chronically undernourished population of the Valley of Mexico City.

Effects of neonatal undernutrition on the electrocortical development of the association areas in the rat.

The electrocortical effects provoked by neonatal undernutrition and the environmental sensorial stimuli were studied in the cortical association areas of developing Wistar rats. When the interaction between these two factors was interfered (Experiment 1), the average frequency of the ECoG in the early starved rats was significantly increased than controls. Moreover, if these two factors were combined (Experiment 2) not significant differences in the ECoG average frequencies were observed. The data suggest that the maturation of cells underlying the ECoG in the association areas of the rat, requires not only an adequate supply of nutrients, but also the influence of sensory cues arising from the mother, littermates and the environmental surrounding.

Effects of thyroxine on the development of self-grooming behavior in rats.

The effects of intraperitoneal thyroxine administration (1 microgram/body weight) on postnatal days 1-3 and the subsequent alterations upon the development of six self-grooming components were measured postnatally in male Wistar rats between days 1-60. Observations on self-grooming components showed that thyroxine-treated rats did not show consistent significant differences in the duration of grooming movements of short displacement directed to the forepaws and head throughout the study, as compared to controls. By contrast, after weaning, the duration of grooming movements of long displacement directed to the fur, genital area, and body scratching were significantly increased. The findings suggest that early thyroxine treatment may primarily interfere with the neural circuitry that modulate long displacement grooming movements, rather than with the substrates controlling short displacement grooming activities. Thus, the hormone might be acting upon neural modulatory systems of self-grooming having different vulnerability in relation to the level of maturity of the brain circuits underlying each grooming component.

Undernutrition induced by early pup separation delays the development of the thalamic reticular nucleus in rats.

A Golgi-Cox study was conducted in neurons of the reticular and lateralis thalamic nuclei in normally and early undernourished Wistar rats at 12, 20, and 30 days of age. In a total of 630 neurons the cell body and the dendritic field areas, as well as the number of dendritic prolongations from camera lucida drawings were quantitated. A general and significant reduction in most reticular thalamic nucleus measurements of early-food-deprived rats was observed compared with control littermates. Additionally, reticular thalamic cells in both normal and neonatally underfed rats exhibited a progressive decline, particularly in cell body area with increasing age. In contrast, the lateral thalamic nucleus did not show significant differences between groups when similar neuronal measurements were carried out. The reticular thalamic nucleus is normally related to the control of sensory afferent transmission, and early food deprivation interferes with the growing process of this nucleus. Therefore the present data support the hypothesis that noxious perinatal environmental influences may result in a maturational deficiency of central nervous system modulatory mechanisms.