The histoenzymic activity of gyrus cinguli in the course of postnatal ontogeny of the rat.

Histochemical investigations concerning the activity of several dehydrogenases and hydrolases in the area cinguli during postnatal ontogenic development of the rat were performed. Brain sections corresponding to the region of area cinguli, obtained from rats aged 1, 3, 8, 17, 40 and 60 days postnatal, were subjected to histochemical assays for various dehydrogenases, phosphatases and esterases. The developmental changes concerning histoenzymic reactivity of the callosal gyrus with regard to several respiratory and hydrolytic enzymes were assessed and described. Considerable differences in enzymic reactivity, appertaining particularly to the phosphatases and esterases, between the anterior and posterior parts of the callosal gyrus were found. The unusual enzymic reactivity of glial cells in the individual regions of the area cinguli has been pointed out.     

The formation of interhemispheric asymmetry in human ontogeny during the perception of emotions in normal speech and in stuttering]

Age peculiarities of functional brain asymmetry in perception of emotional information of speech have been revealed. It was shown that the age of 4-7 years is most important for formation of this asymmetry in emotional perception. It is in this age that functional reorganization of perception in stuttering children is observed. These data indicate that correction of emotional activity in stutterers should be made at early periods of their life.     

Maternal perception of fetal motor activity.

A technique using real-time ultrasound for comprehensive recording of fetal motor activity was used in 20 subjects in the third trimester of pregnancy. Maternal awareness of fetal movement correlated with the number of fetal parts contributing to the movement but not with maternal parity or obesity, gestational age, placental site, or duration of the fetal movement. Some subjects recorded fetal breathing, passive fetal displacement, and Braxton Hicks''s contractions as fetal movement. Most of our subjects were consistent and accurate in their perception of major fetal movements, but a few were inconsistent and one was completely unaware of major fetal movements. These results suggest that kick counts kept by most mothers will be accurate. Low counts of fetal movement should be an indication for fetal monitoring by other means and not, unconfirmed, for intervention.     

The perception of painful and nonpainful stimuli during voluntary motor activity in man

Previous studies have shown that voluntary movement diminishes the transmission of cutaneous afferent input through the dorsal column-medial lemniscal system, and also raises the threshold for detecting nonpainful, cutaneous stimuli (electrical shocks). Although there is some evidence that pain elicited by electrical stimulation is diminished during movement, no studies have tested the effect of movement on the perception of pain produced by natural stimulation. For this reason, we tested the effects of voluntary motor activity on the perception of noxious thermal stimuli in human volunteers. We first developed a motor paradigm in which the thermal stimulation could be applied to the immobile limb (isometric elbow flexion-extension). Both isometric and isotonic muscle contractions about the elbow increased the threshold for detecting weak cutaneous stimuli (electrical shocks) applied to the forearm, and to a lesser extent the detection of stimuli applied to the dorsum of the hand. Afterwards, noxious and innocuous heat stimuli were applied to the forearm during isometric contractions and at rest. Magnitude estimates for the intensity of the pain, as well as latency measures of the onset of pain, were recorded. We found no evidence that isometric motor activity diminished either the threshold for pain or the subjective intensity of the noxious and innocuous thermal stimuli. Thus, motor activity decreases the ability to detect weak low-threshold cutaneous inputs, but has no effect on the perception of warmth and heat pain.     

The effect of different anamnesis during ontogeny on higher nervous activity in rats.

The consequences of malnutrition, experimental experience and sensory deprivation during early postnatal life were investigated in adult rats. The higher nervous activity of experimental animals was evaluated by means of a battery of tests (exploratory activity, avoidance reaction, preference of a small chamber and a water maze). Rats were divided into 5 groups, i. e. control, trained (with previous experimental experience), light deprived, malnourished naive (12-14 animals in the litter) and malnourished trained. From experimental data obtained it may be concluded that the level of nutrition as well as sensory deprivation or additional stimulation during development are important factors the influence of which persists and modifies the somatic development and the higher nervous activity in adult animals. Light deprived and malnourished rats showed retarded somatic development and worse parameters of higher nervous activity. The difference between groups could be altered by augmented stimulation. Previous experimental experience and intensive handling seems to be an important factor which influences the higher nervous activity of experimental animals.     

The effect of phosphorus on nodule formation and function in the Casuarina-Frankia symbiosis

A study was conducted to investigate the effects of phosphorus on nodule formation and function in the Casuarina-Frankia symbiosis. The effects of P on growth and survival of Frankia in the rhizosphere was assessed by examing Frankia growth and survival in flasks of basal nutrient solution. There was no growth in the nutrient solution during the experimental period. However, the viability of Frankia in the nutrient solution without P supply was half that of the initial level, whereas, with P supply, there was only a minor decline during the first week. In a growth pouch experiment, supplying P increased plant and nodule growth, irrespective of P status of the inoculant Frankia culture. There were no effects of P status on any growth or nodulation parameters measured when the inoculants had been standardized on the basis of viability. In a split root experiment, Frankia inoculation and application of P together or separately did not cause any significant difference. This suggests that growth and nodulation respond only to total P supply. Increasing P from 0.1 to 10 M significantly increased plant growth but not N concentrations. Both nitrogen-fixation and nitrate supported growth were strongly increased as P increased from 0.1 to 1.0 M. This study indicates that P deficiency limits the growth of host plants more severely than nitrogen fixation processes and P deficiency on nodulation and symbiotic nitrogen fixation in Casuarina cunninghamiana operated indirectly via reducing host plant growth.     

The characteristics of motor asymmetry in the ontogeny of calves]

The side of preference (first turn of head) was recorded in calves in situation of free equal probability two-sides choice, and rate of reconstruction of conditioned reflex to food presented from the left or from the right was determined. Initially the calves preferred the left turn, i.e. manifested motor asymmetry. Preference to the left turn changed depending on the calves age with the period of 22-23 days. The rate of conditioned reflexes reconstruction was higher in calves with the left-side preference. Correlation of the motor asymmetry and rate of conditioned reflex reconstruction in calves of different age changed in analogy with age changes of asymmetry. Probably the observed periodical changes of asymmetry and its correlation with the rate of reconstruction reflect formation of interhemispheric interactions in regulation of the organism functions in animals ontogenesis.     

The formation of predatory aggressiveness in the ontogeny of rats

In tests on outbred male rats the problem was studied of the existence of "sensitive periods" in the formation of rats predatory aggression. Breeding of small rats together with mice from the first till 60-th postnatal day considerably inhibits their muricidity in the adult age, what is manifest in tests of predatory aggressiveness till the 270-th day of rats life. Breeding of mice together with rats in the age of 1-20, 20-40, 40-60 and 20-60 postnatal days does not influence significantly their muricidity. Antiaggressive effect of breeding of mice with adult rats from the 150-th to the 210-th day is a short-term one, and breeding of mice with old rats in the age of 540-600 postnatal days does not significantly effect the muricidity.     

The formation of activity-rest cycles in early ontogeny

The cyclic variations of the motor activity consist of many rhythmic components which appear nonsimultaneously in the ontogenesis. The earliest component is the autogenic periodic motility with the duration about one minute which can be observed in rats during first two-three weeks after the birth. From the second week a new type of cyclic activity appears. It can be qualified as a sleep-wakefulness cycle with the duration about several minutes. It is suggested that this cycle is a true novel rhythm which is able to modulate the earliest more frequent periodicity.     

The time course of synapse formation of mouse neuroblastoma cells in monolayer cultures

Summary Neuroblastoma cells grown on substrates in culture develop long processes and assume the morphology of normal neurons as judged light microscopically. The development of synapses in the cultured tissue is studied by periodic electron microscopic examination of the areas of contact between cells. The initial expiants are free of any apparent synaptic contacts. After 48 h in culture, simple swellings or boutons are detected at the periphery of the cells or at the end of the fine processes. These initial synaptic profiles contain a few vesicles but lack mitochondria. The synaptic vesicles appear to originate from the smooth endoplasmic reticulum. Further expiants remain primitive, only the number of vesicles in the cytoplasmic swellings or boutons increases. These clusters of vesicles are 40–60 nm in diameter and morphologically distinguishable from the synaptic vesicles of normal neurons. There are no postsynaptic folds or membrane thickenings. Specialized cell contacts between cells are also present.     

The effect of noise and vibration on motor activity and behavioral tests in rats

The investigations were carried out on 80 Albino rats. It was found that a single exposure to noise alone or noise coupled with vibratio;n increase locomotor and exploratory activities of the rats. On the other hand, repeated exposures to noise and low frequency vibration failed to change the exploratory activity and behavioral tests of rats. No significant differences were found between the effects of noise alone and associated with vibration.     

The ontogeny and maintenance of adult symmetry properties in the ctenophore, Mnemiopsis mccradyi

Ctenophores are biradially symmetrical animals. The body is composed of four identical quadrants which are organized along an oral-aboral axis. Most species have eight comb rows, two tentacles, and an apical organ (located on the aboral surface). During embryogenesis there is a fixed pattern of cleavage, a precocious specification of blastomere developmental potential, and an inability to regulate for portions of the embryo that have been removed. When blastomeres are separated at the two-cell stage each blastomere develops into a "half-animal" with four comb rows, one tentacle, and half an apical organ. In contrast, adult ctenophores regenerate readily. When an adult ctenophore is cut in half to produce "half-animals," in most cases each half regenerates the missing half. In some cases, however, bisected animals remain as "half-animals" which repair the wound site but do not replace all of the missing structures. When animals are cut in half along the tentacular or esophageal axis at different stages of embryogenesis a transition period is detected when the capacity for adult regeneration begins. This transition occurs at the time when the formation of the apical organ is complete and comb row function becomes coordinated. Embryos bisected prior to this time remain as "half-animals" even after growing to large reproductive sizes, while animals bisected after the transition period usually regenerate the missing structures within 2-3 days. When adult "half-animals" (produced by bisection either before or after the transition period) are cut into "quarter-pieces," the pieces regenerate to form either "half-animals" or whole animals. Thus, "half-animals" produced prior to the transition period--although they failed to undergo embryonic regulation--have not irreversibly lost the capacity to form whole animals if challenged to regenerate during adult stages. When aboral blastomeres destined to form the apical organ, tentacles, and comb rows are removed from early cleavage stages (prior to the transition period), the embryo does not form these structures at the appropriate time. However, the resulting deficient adults spontaneously form these structures from remaining blastomere lineages soon after hatching. These experiments suggest that as long as some quadrant-specific cells of the oral pole are present at the time of the transition period, the structures of that quadrant will be spontaneously replaced during the adult period.(ABSTRACT TRUNCATED AT 400 WORDS)     

The effect of pentagastrin and ornithine-tetragastrin on motor activity of the stomach in skates and scorpion-fish]

Low doses of pentagastrin (50 mug/kg b. w.) have no physiological effect on motor activity of the stomach in the skate Dasyatis pastinaca. Average doses (100-200 mug/kg) stimulate the activity, whereas high ones (300 mug/kg) inhibit the frequency of stomach contractions, slightly increasing their amplitude. Ornithine tetragastrin in a dose 2000 mug/kg does not affect motor activity of the stomach in skates. In the scorpion-fish Scorpaena porcus, ornithine tetragastrin (1000 and 2000 mug/kg) inhibits motor activity of the stomach.