Behavioral effects of protein deprivation and rehabilitation in adult rats: relevance to morphological alterations in the hippocampal formation.

In the present study we have analyzed the behavioral and neuroanatomical effects of protein deprivation in adult rats. Starting at 2 months of age, animals were maintained on 8%-casein diet either for 8 months (malnourished group), or for 6 months followed by a 2-month period of nutritional rehabilitation (17%-protein diet, rehabilitated group). Malnourished rats exhibited reduced emotional reactivity and impaired habituation in the open field. In a water maze, these animals did not differ from controls during training, but showed retention deficits on the probe trial. However, working memory, sensorimotor abilities and passive avoidance behavior were not significantly impaired in malnourished rats. The performance of rehabilitated group was similar to that of the control group throughout behavioral testing. Postmortem morphological analysis revealed that the total number of neurons in the granular layer of the dentate gyrus, and in CA3 and CA1 hippocampal fields was reduced in protein-deprived and rehabilitated rats relative to controls. In addition, it was found that protein deprivation caused a 30% loss of synapses established between mossy fibers and dendrites of CA3 pyramidal cells, whereas nutritional rehabilitation resulted in a reversal of this effect. These results show that prolonged malnutrition in adult rats produces marked loss of hippocampal neurons and synapses accompanied by substantial impairments of hippocampal-dependent behaviors. The fact that nutritional rehabilitation results in restoration of the total number of hippocampal synapses and parallel amelioration of the behavioral impairments suggests that the mature CNS possesses a remarkable potential for structural and functional recovery from the damage induced by this type of dietary insult.

Utilizaçäo da ictiofauna acompanhante da captura do camaräo sete-barbas na forma e produto salgado, prensado e seco: características física, química e nutricional / Utilization of seabob shrimp by catch as a salted, pressed and dried product: physical, chemical and nutricional characteristics

O objetivo do presente estudo foi avaliar as características de produto salgado, prensado a seco, obtido da mistura de diferentes espécies de peixes capturados junto com o camaräo sete-barbas, através de análises física, química e nutricional. Com base em tais análises, verifica-se que o produto possui qualidades adequadas para uso em alimentos destinados à suplementaçäo alimentar de dietas deficientes de proteínas. O teste biológico mostrou um CEP de 3.23, considerando bom, quando comparado com o CEP de 2,97 da caseina.Foram preparados vários produtos com o bloco de pescado salgado, prensado e seco, sendo aceitos para alimentaçäo

Visual discrimination in rats: the effects of rehabilitation following intergenerational malnutrition.

The effect of rehabilitation following intergenerational malnutrition in rats was observed using 3 tests of visual discrimination (Lashley tests). The following groups were studied at 3 months of age: animals nutritionally deprived of protein for many generations (intergenerational malnutrition), those from the same stock rehabilitated for 1 to 2 generations at an adequate protein level, and controls from a stock never exposed to malnutrition. Males rehabilitated for 2 generations showed some improvement in performance in the Lashley tests, but did not attain the level of well-nourished controls. In agreement with the earlier data, females were less susceptible to behavioral deficits from intergenerational malnutrition and recovery was observed after 1 generation of rehabilitation. Growth of both males and females rehabilitated for 1 or 2 generations was superior to that of control rats.

Effects of rehabilitation on the jaws and teeth of protein-deficient and calorie-deficient pigs.

The growth of the jaws and teeth was examined in pigs which had been fed protein-deficient and calorie-deficient diets for the first year of life and thereafter allowed unlimited food. After 2 years of rehabilitation, jaw size had almost reached that of well-fed controls, although in the mandible the labial alveolar process remained abnormally proclined and in both jaws the crowns of third permanent molars were smaller than in control animals. Calorie-deficient pigs did not recover as well as did protein-deficient animals. Pigs fed a calorie-deficient diet for the first 2 years of life before rehabilitation also made a good recovery and were only slightly smaller in most dimensions than those undernourished for 1 year and then rehabilitated. Despite the excellent recovery in jaw dimensions, some malposition of teeth persisted after rehabilitation, especially in animals which had been undernourished for 2 years.

The role of mucosal iron binding proteins in adaptation of iron absorption during protein deficiency and rehabilitation.

1. A state of protein deficiency has been produced in rats by feeding a low protein diet, thereafter a period of rehabilitation with a normal protein but a low iron supply followed. 2. For characterization of the iron metabolism during both periods haemoglobin, total iron binding capacity, liver non-haemin iron, intestinal iron absorption and the uptake of 59Fe in the liver was determined. 3. Under these conditions the amount of 59Fe incorporated into the mucosal transferrin and the ferritin fractions has been measured. Both fractions were obtained from the supernatant of a mucosal homogenate after chromatography on sepharose 6B. 4. In anemia due to protein deficiency the typical increase of 59Fe incorporation into the fraction of mucosal transferrin--usually occuring in iron deficiency--could not be observed. This coincides with the absence of an increased iron absorption. Moreover a decrease of iron absorption is observed, which is associated with a decreased 59Fe ratio of transferrin/ferritin-fraction. 5. After normalization of the protein supply the ratio of 59Fe incorporated into the mucosal transferrin and ferritin fractions was changed remarkably in favor to transferrin together with a several fold increase of the intestinal iron absorption. 6. The conclusion is drawn that mucosal transferrin and ferritin enable the body not only to adapt the absorption to a higher but also to a lower requirement as it is the case in protein deficiency.

Early protein malnutrition in the rat: behavioral changes during rehabilitation.

Behavioral development was studied in 2 groups of rats during the postweaning period. Pups were selected from litters nursed by dams fed either a standard protein (25% casein by weight) or a low protein diet (12% casein) during lactation. Two pups from each litter were housed together and fed the control diet throughout rehabilitation. Behavioral observations were made by repeated time-lapse photography at 5-day intervals. Differences in home cage behavior were observed at the onset of rehabilitation in the postnatally malnourished rats. Increased feeding behavior was observed during the 1st week of rehabilitation. Locomotor behavior was depressed during the rehabilitation period in the experimental animals. Climbing activity, however, was significantly greater. Self-grooming activity was elevated throughout rehabilitation in post-natally malnourished animals. During the course of rehabilitation, the behavioral differences between the 2 groups gradually disappeared.