Effects Of Tactile Stimulation Research Articles

The Skin as a Neurodevelopmental Interface

After completing this article, readers should be able to: 1. Characterize the incidence of severe neurodevelopmental handicaps in very low-birthweight infants over the past decade. 2. Define severe neurodevelopmental deficits. 3. Characterize the derivation of the brain and the epidermis. 4. Describe the possibilities of evoked potential testing for evaluation of brain function in asphyxiated and very low-birthweight preterm infants. 5. Characterize in utero development of the high electrical resistance of skin. “Compared with newborns of other species, the human neonate is relatively helpless in motor capabilities and relatively precocious in sensory capabilities.” —T. Berry Brazelton Behavioral Competence Avery’s Neonatology . 5th ed. 1999 Accumulating evidence suggests a connection between the developing brain and the developing skin. In this view, the skin, broadly considered, functions as a neurodevelopmental boundary in the very low-birthweight (VLBW) preterm infant. The epidermis, for example, plays a role as a specialized ectodermal derivative closely linked to both neuroperception and noninvasive monitoring in intensive care environments. The terminal differentiation product of the epidermis, the stratum corneum, is considered a prototypical smart material. The concept of the skin as a neurodevelopmental interface may be broadened to include its role as an interface with the caregiver and a boundary for primary care delivery in the neonatal intensive care unit. Recent reviews have demonstrated the persistence of a high incidence of severe neurodevelopmental disability in VLBW preterm infants (Fig 1⇓ ). (1) Severe neurodevelopmental disability generally is defined as subnormal cognitive function, cerebral palsy, blindness, deafness, or a combination of these factors. The continuing high incidence of neurodevelopmental handicap raises several questions: 1) Given the complexity and relative inaccessibility of the central nervous system (CNS), is it advantageous to consider alternative viewpoints for the etiology and therapy of neurodevelopmental handicaps? 2) Given the close embryologic connection between brain and skin, should cognition be …

Tactile hyperesthesia, altered epidermal innervation and plantar nerve injury in the hindfeet of rats housed on wire grates

The effects of wire grates on nerve injury and recovery were examined in rats housed in cages with sawdust-covered solid flooring. For the first 3 weeks of the study, 20 rats were housed on sawdust alone and 20 rats were housed in cages with wire grates placed over the sawdust. For the remaining 9 weeks, 10 animals housed on sawdust had wire grates added to their cages, while grates were removed from the cages of 10 animals. The effects of tactile stimulation on hindpaw plantar skin was measured weekly using the Von Frey filament test. Intraepidermal innervation using PGP 9.5 immunostaining and plantar nerve histology were assessed at the end of the 12-week study. After just 1 week on grates, hindpaw withdrawal thresholds were already markedly decreased and remained low until the grates were removed at 3 weeks. Thresholds returned to normal by 4 weeks after removal of the grates. Wire grates also induced increases in PGP 9.5 immunoreactive intraepidermal fine nerve endings that were normalized after grate removal. Demyelination, Wallerian degeneration and Renaut bodies were induced in the medial plantar nerve in rats housed in cages with wire-grate flooring. Nerve injury was largely resolved after 9 weeks on sawdust flooring. These data demonstrate that wire grates rapidly induce hindpaw tactile hyperesthesia and plantar neuropathy in rats and emphasize a risk of using wire-grate cage flooring in studies assessing hindlimb function and structure.

Effect of tactile stimulation on serum lactate in the newborn rat.

Maturation of the CNS in neonatal animals is dependent upon both sensory input and the constant availability of metabolic fuel. Previous reports indicate that the preferred metabolic substrate for the developing rat brain is lactate. In this study, we used the neonatal Sprague-Dawley rat to investigate a possible interactive role between touch and the regulation of serum lactate. Two hundred and fifty rats (postnatal d 0-7) were exposed to a standard tactile stimulation (TS) regimen to mimic nonspecific maternal stimulation. This regimen consisted of stroking the dorsum with a soft camel hair brush for 30 s every minute for 10 min. Serum lactate and glucose levels were measured after TS. In newborn (d 0) rats, lactate levels were increased by 207% in stroked pups versus controls. This elevation of serum lactate persisted for 30 min after cessation of TS. On d 7, TS increased lactate only 11%. Glucose levels were unaffected at all ages. In neonatal pups, pretreatment with pentobarbital blocked the effect of TS, whereas epidermal growth factor evoked a synergistic response. Capsaicin pretreatment had no effect. Mixed arteriovenous blood gases revealed a mild increase in pH and a decrease in Pco2 after TS. We conclude that TS in newborn rats is a regulator of circulating lactate. This response is maximal in the immediate postnatal period and wanes over the 1st wk of life. We speculate that the transduction of sensory signals by the skin is a mechanism regulating the availability of cerebral energy substrates in the newborn mammal.

Noncontingent Application Versus Contingent Removal of Tactile Stimulation: Effects on Self-injury in a Young Boy with Multiple Disabilities

This study examined the effects of tactile stimulation on self-injurious behaviour (SIB) in a 10-year-old boy with developmental disabilities. SIB occurred at high rates during unstructured play, suggesting an automatic reinforcement, sensory stimulation function. Noncontingent application of an alternative source of tactile stimulation produced only modest reductions in SIB, but contingent removal of the objects used to obtain tactile stimulation produced clinically significant reductions.

Norepinephrine-induced plasticity and one-trial olfactory learning in neonatal rats

The influence of norepinephrine (NE) on the acquisition of a conditioned odor preference and enhanced focal uptake of [ 14C]2-deoxyglucose (2-DG) within the olfactory bulb was assessed in neonatal rat pups. On postnatal day (PN) 6, pups were injected with either an NE receptor agonist (isoproterenol), NE receptor antagonist (propranolol or timolol), or saline before one-trial odor conditioning. The experimental conditioning group received a 10-min exposure to an odor (peppermint) and reinforcing tactile stimulation similar to that received from the dam. Control groups received only the odor, only the tactile stimulation, backwards presentation of the odor and tactile stimulation or neither of these stimuli. The next day, pups were either tested for an olfactory preference (Expts. 1 and 2) or assessed for differential olfactory bulb activity using the 2-DG technique (Expt. 3). The results indicate that early odor experience with either tactile stimulation or isoproterenol is sufficient to produce a learned behavioral preference and enhanced focal 2-DG uptake within the olfactory bulb. Moreover, an NE receptor blocker injected prior to training with odor and tactile stimulation blocks the acquisition of both behavioral preference and the enhanced 2-DG uptake. In Expt. 4, the effects of tactile stimulation and isoproterenol were further assessed. An odor paired with a moderate level of either of these stimuli produces learning. However, the simultaneous presentation of a moderate level of these stimuli paired with an odor does not result in an odor preference. An odor preference may be reinstated by simultaneous presentation of these stimuli, provided the level of each of these stimuli is too low to produce an odor preference when presented alone with an odor. These data suggest that exogenous NE and tactile stimulation are additive in their effect on learning. These results are discussed in terms of the neural mechanisms underlying reinforcement in infant rats.

Effects of tactile stimulation and gross motor movement on cognitive learning: A test of Montessori's muscular movement theory in the college classroom

A considerable amount of research has been dedicated to understanding the relationship between teacher behaviors in the classroom and student learning. Three theories (i.e., arousal theory, depth‐of‐processing theory, and muscular movement theory) have been proposed to explain increases in cognitive learning. Both arousal theory and depth‐of‐processing have been empirically tested. The purpose of the present investigation was to test the viability of muscular movement theory. A field experiment was conducted to determine if the use of tactile stimulation in conjunction with gross motor movement exercises would increase cognitive learning (i.e., examination scores) of college students. The results of the study support the hypothesis.

Effects of Tactile Stimulation on Physical Growth and Hypoxemian in Preterm Infants

Effects of Tactile Stimulation on Physical Growth and Hypoxemian in Preterm Infants

Effects of Tactile Stimulation on Physical Growth and Hypoxemian in Preterm Infants

The risk and benefit effects of tactile stimulation on hypoxemia and physical growth were evaluated on preterm infants born at 30 to 32 weeks of gestation. During 10 days, tactile stimulation was administered twice daily, for a period of 15 minutes, to the trunk and extremities. Physical growth measurements included weight, height and head circumference. Constant control of oxygen saturation and heart rate before, during and after each intervention, was used to identify hypoxemia. Tactile stimulation, as given, had no statistically significant effect on physical growth but did not provoke hypoxemia. Further studies are needed to determine the specific components of this modality which might give positive results on the physical growth of preterm infants.

Effects of Tactile Stimulation on Premature Infant Weight Gain

A study was conducted to determine the effect of continuous tactile stimulation on weight gain in premature infants. Thirty infants made up the sample. The experimental group received continuous tactile stimulation by being placed on a pile decubitus pad for a five-day period. Infants in the control group received routine nursery care. Both groups were weighed daily on the same scale. Analysis of covariance was used to analyze the data, which resulted in a failure to reject the hypotheses of no difference.

Effects of tactile stimulation on low and very low birthweight infants during the first week of life

Thirty-one low and very low birthweight infants were given tactile stimulation during the first week of life. Compared with the control group of 35 they showed less weight loss. When stimulation was started within the first 48 hours, there was significantly less weight loss than when it was started in the interval 49 to 120 hours.

Heart rate response to touch.

The effect of tactile stimulation on heart rate (HR) in humans was investigated under three conditions: 1) Experimenter outside of room in which subject is sitting; 2) experimenter in the room with the subject; 3) experimenter in the room while touching the subject's right wrist. Nonsignificant increases in HR were observed when the experimenter entered the room (X = 0.64 beats per minute (bpm)). Conversely, large decreases occurred when the experimenter placed his hand on the subject's wrist (X = 9.16 bpm, p is less than 0.05). To determine if tactile stimulation alone accounts for these differences three comparisons were made in a second experiment: 1) Experimenter out of test room, subject touches own wrist; 2) experimenter in room standing near subject; 3) experimenter touching subject's wrist. Subjects showed slightly elevated HR during the self-touch condition (X = 1.26 bpm, not significant). Although no change was noted with the experimenter standing beside the subject, there were decreases, as in Experiment I, when the experimenter touched the subject's wrist (X = 1.75 bpm, p is less than 0.05). These results suggest that the observed decreases in HR were contingent upon another person's touch. While self-tactile stimulation produced a slight increase in HR, tactile stimulation by another caused bradycardia.

The effects of tactile stimulation on imprinting in ducklings after the sensitive period

Four-day-old ducklings received visual-plus-tactile exposure to one novel object and visual-only exposure to a different novel object. In a subsequent test, strong suppression of ongoing distress vocalization was exerted only by the object to which visual-plus-tactile exposure had been given. With these results, the experimental conditions under which physical contact is known to facilitate the initiation of imprinting are extended to include subjects that are past the sensitive period.

Effects of tactile stimulation on the initiation and maintenance of the following response in Japanese quail (Coturnix coturnix japonica)

Effects of tactile contact with an imprinting stimulus object on the initiation and maintenance of the following response in neonatal Japanese quail,Coturnix coturnix japonica, were examined. Tactile contact with an imprinting stimulus object was permitted during a preexposure period and/or during a following test. Results indicated that following was stronger when tactile contact was permitted during either the preexposure or test periods than when such contact was not given. Following occurred sooner when contact was permitted during the preexposure period than during following only, or when no contact was permitted. The greatest strength of following occurred when tactile stimulation was permitted during both preexposure and testing periods. It was concluded that the results support the hypothesis that tactile stimulation can facilitate both the initiation and maintenance of following behavior, and this is interpreted as being consistent with Schneirla’s (1965) theory.