Early Environmental Stimulation Research Articles

Early social enrichment rescues adult behavioral and brain abnormalities in a mouse model of fragile X syndrome.

Converging lines of evidence support the use of environmental stimulation to ameliorate the symptoms of a variety of neurodevelopmental disorders. Applying these interventions at very early ages is critical to achieve a marked reduction of the pathological phenotypes. Here we evaluated the impact of early social enrichment in Fmr1-KO mice, a genetic mouse model of fragile X syndrome (FXS), a major developmental disorder and the most frequent monogenic cause of autism. Enrichment was achieved by providing male KO pups and their WT littermates with enhanced social stimulation, housing them from birth until weaning with the mother and an additional nonlactating female. At adulthood they were tested for locomotor, social, and cognitive abilities; furthermore, dendritic alterations were assessed in the hippocampus and amygdala, two brain regions known to be involved in the control of the examined behaviors and affected by spine pathology in Fmr1-KOs. Enrichment rescued the behavioral FXS-like deficits displayed in adulthood by Fmr1-KO mice, that is, hyperactivity, reduced social interactions, and cognitive deficits. Early social enrichment also eliminated the abnormalities shown by adult KO mice in the morphology of hippocampal and amygdala dendritic spines, namely an enhanced density of immature vs mature types. Importantly, enrichment did not induce neurobehavioral changes in WT mice, thus supporting specific effects on FXS-like pathology. These findings show that early environmental stimulation has profound and long-term beneficial effects on the pathological FXS phenotype, thereby encouraging the use of nonpharmacological interventions for the treatment of this and perhaps other neurodevelopmental diseases.

Detection of long-term influence of prenatal temperature stimulation on hypothalamic type-II iodothyronine deiodinase in juvenile female broiler chickens using a novel immunohistochemical amplification protocol

It has been clearly shown that early environmental stimulation may have long-lasting influence on body functions. Because of the strong relationship between thermoregulation and other homeostatic linked physiological parameters, perinatal thermal manipulation will also have an impact on other body functions like reproduction. As a maturation stimulant for later reproductive performance, hypothalamic type-2 iodothyronine deiodinase (Dio2) expression was investigated in 35day old immature female broilers with and without embryonic temperature stimulation. For the first time, human-specific Dio2 primary antibodies combined with additional amplification enabled the immunohistochemical detection of hypothalamic Dio2 protein in birds. The novel protocol includes an additional amplification step involving swine-anti-rabbit/mouse/goat antibodies against both goat anti-Dio2 primary and rabbit anti-goat biotinylated secondary commercial antibodies in the standard diaminobenzidine protocol. However, significant Dio2 expression was exclusively found in perinatally short-term temperature stimulated hens. Caudal but not rostral hypothalamic slices revealed that elevating incubation temperature by 1°C for 2h daily, from day 18 of embryonic development until hatching, induced a statistical significant expression of Dio2 within the subcommisural organ and the median eminence. This ample expression of Dio2 protein within caudal but not rostral hypothalamic slices of embryonic temperature stimulated chickens, leads to the assumption of a novel physiological prospective for embryonic thermal manipulation involving the suppression of thyroid hormone and the boosting of hypothalamic Dio2-induced FSH secretion to considerably advance the age of photoinduced egg production. It could be also of practicable relevance for broiler breeder females, and needs further investigations.

Environmental Novelty Activates β2-Adrenergic Signaling to Prevent the Impairment of Hippocampal LTP by Aβ Oligomers

A central question about human brain aging is whether cognitive enrichment slows the development of Alzheimer changes. Here, we show that prolonged exposure to an enriched environment (EE) facilitated signaling in the hippocampus of wild-type mice that promoted long-term potentiation. Akey feature of the EE effect was activation of β2-adrenergic receptors and downstream cAMP/PKA signaling. This EE pathway prevented LTP inhibition by soluble oligomers of amyloid β-protein (Aβ) isolated from AD cortex. Protection by EE occurred in both young and middle-aged wild-type mice. Exposure to novelty afforded greater protection than did aerobic exercise. Mice chronically fed a β-adrenergic agonist without EE were protected from hippocampal impairment by Aβ oligomers. Thus, EE enhances hippocampal synaptic plasticity by activating β-adrenoceptor signaling and mitigating synaptotoxicity of human Aβ oligomers. These mechanistic insights support using prolonged exposure to cognitive novelty and/or oral β-adrenergic agonists to lessen the effects of Aβ accumulation during aging.

Early Enriched Environment Promotes Neonatal GABAergic Neurotransmission and Accelerates Synapse Maturation

Environmental stimulation is critical for brain development. Here, we report that natural stimulation through enriched environment (EE) rearing during the first 2 weeks of mouse postnatal development promotes GABAergic neurotransmission and accelerates maturation of GABAergic and glutamatergic synapses. Using whole-cell recordings from CA1 pyramidal neurons in acute hippocampal slices, we found that EE-reared mice exhibited higher amplitude of miniature GABAergic postsynaptic currents (mGPSCs) at 1 week of postnatal development, as well as accelerated transition of GABA action from excitation to inhibition, compared with mice reared under standard housing conditions. This enhanced GABAergic synaptic transmission persisted until the end of the second postnatal week, when GABA mostly acts as an inhibitory neurotransmitter. Consistent with these electrophysiological results, we observed elevated levels of GABA(A) receptors and the K(+)-Cl(-) cotransporter KCC2. Similarly, increased levels of excitatory synaptic components, including NMDA and AMPA receptors and the scaffolding protein PSD95, were detected in synaptosomal fractions from the forebrain/hippocampus of EE-reared mice during the first two postnatal weeks. Functional increase in glutamatergic synaptic transmission, as measured by increased amplitude of miniature and spontaneous EPSCs, was also detected during the second postnatal week. Together, these results demonstrate that early environmental stimulation through EE rearing enhances early postnatal GABAergic neurotransmission, which is known to play important trophic functions in many aspects of neural development.

Cleft palate: modern technology and neuroscience merge.

This is a report of a cleft palate-craniofacial team's experience with 768 patients that have had clefting over 22 years, with a primary focus on function and prevention of communication disorders associated traditionally with cleft palate. The treatment philosophy is based on tenets of child development and the dependency of neuropsychobiological development on the child's inherent competency, and early environmental stimulation and support. The applied treatments include ensuring early and adequate hearing, psychosocial adaptation of the parent and child through training for applications of indirect therapies, and early fistula-free surgical closure of the cleft that produces minimal scarring and a mobile velum. Team members have extensive backgrounds in child development that seem to have helped the majority of families in their complex efforts of daily care and sensory stimulation, and their children have developed early the ability to adapt modified structures to normal functions. Only one of these patients has needed or received secondary palatal surgery for correction of velopalatal insufficiency. Fifty-six children who did not achieve acceptable 2 to 3-year old communication criteria were referred for speech and language evaluation and therapy. These patients were reported to exhibit oral motor deficits described as developmental verbal dyspraxia.

Infant Stimulation and Development

Abstract The last several years have witnessed a growing interest in infant development, and growing concern about infant stimulation. This discussion examines the assumptions about development that underlie the premise that developmental outcomes can be significantly improved by providing early environmental stimulation. Those assumptions include: (a) that infant development is more influenced by environmental factors than by biological/genetic factors; (b) that development is linear and continuous, and that infant development is predictive of later function; (c) that early experiences determine later development; (d) that the normal social environment may be inadequate for optimal development and require improving. Research and theory from developmental psychology provide a different perspective, and a different set of assumptions. Implications for infant intervention and stimulation programs are discussed.

Predicting intellectual outcomes: Sex differences in response to early environmental stimulation

Sex differences in parent-child interaction and infant development patterns were examined in a longitudinal sample of 193 parent-infant pairs. Few differences were found. However, there were differences in the patterns of prediction of later intellectual and linguistic outcomes for boys and girls. Stronger predictions of IQ or language skill were obtained for boys from measures of the mother's developmental expectations, the extent of the father's involvement in the infant's early care, the provision of appropriate play materials, and the extent of parental life change. Stronger predictions were found for girls for a measure of restriction and punishment. The combination of these two groups of findings — lack of difference on measures of environment and parent-child interaction, and the presence of differences in prediction — suggest that the same experiences produce difference effects for boys and girls.

Visual and tactual variation seeking in the rat: intermodal effects of early rearing.

AbstractConditions of variation and constancy for both tactual and visual stimulation were arranged in a 2 × 2 factorial. Hooded rats were reared under these conditions from 23 to 39 days of age, following which they lived in standard laboratory cages until 49 days of age. Preference tests for variation vs. constancy in both tactual and visual preference tests were conducted at 48 and 49 days of age. Ss previously exposed to the variable stimulation conditions, either tactual and/or visual, showed equal preference for variable stimulation in both tests. This was in contrast to the controls, which preferred the less variable stimulation in both tests. The intermodal effects of the early environmental stimulation were discussed in terms of Fiske and Maddi's activation model.