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S Pulido

Publications and source records attributed to S Pulido.

12 recordsLinked to original sources
PubMed1991

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.

Aging↗
PubMed1986

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.

Animals↗
PubMed1984

Long-term alterations in the maternal behavior of neonatally undernourished rats.

The effect of early food and sensory deprivation on the maternal responsiveness of female rats was investigated. Animals that were neonatally undernourished by daily mother-litter separation (involving both food and sensory deprivation) showed significant deficits in maternal care, consisting of a reduction in nest rating, nursing time, and retrieving responses. Moreover, they exhibited exaggerated grooming and circling movements in comparison with the controls. Dams neonatally undernourished by the nipple-ligation of their mothers (a method that minimizes sensory deprivation) displayed less alterations in maternal behavior, and no significant differences in grooming and circling from the controls. The data suggest that nest rating, nursing time, and retrieving latency are closely related to food restriction, while the frequency of grooming and circling behavior are primarily associated with sensory deprivation. These results support the view that environmental influences related to food intake and sensory stimulation, interacting at critical stages of brain development, are essential for the maturation of adult behavioral patterns.

Animals↗
PubMedDate not supplied

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.

Animals↗
PubMedDate not supplied

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.

Animals↗
PubMedDate not supplied

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.

Animals↗