Stella Maris Scientific Institute

Pisa, Italy

Stella Maris Scientific Institute

Pisa, Italy
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Baldini S.,Normal School of Pisa | Baldini S.,Stella Maris Scientific Institute | Restani L.,National Research Council Italy | Baroncelli L.,National Research Council Italy | And 7 more authors.
Journal of Neuroscience | Year: 2013

Early life experiences can affect brain development, contributing to shape interindividual differences in stress vulnerability and anxiety-like behavior. In rodents, high levels of maternal care have long-lasting positive effects on the behavior of the offspring and stress response; postweaning rearing in an enriched environment (EE) or massage counteract the negative effects of maternal separation or prenatal stressors. We recently found that insulin-like growth factor 1 (IGF-1) is a key mediator of early EE or massage on brain development. Whether early enrichment of experience can induce long-lasting effects on anxiety-like behavior and whether IGF-1 is involved in these effects is not known. We assessed anxiety-like behavior by means of the elevated plus maze in control adult rats and in adult rats subjected to early EE or to massage. We found that both EE and massage reduced adult anxiety-like behavior. Early IGF-1 systemic injections in rat pups reared in standard condition mimic the effects of EE and massage, reducing anxiety-like behavior in the adult; blocking early IGF-1 action in massaged and EE animals prevents massage and EE effects. In EE and IGF-1-treated animals, we assessed the hippocampal expression of glucocorticoid receptors (GRs) at postnatal day 12 (P12) and P60, finding a significantly higher GR expression at P60 for both treatments. These results suggest that IGF-1 could be involved in mediating the long-lasting effects of early life experiences on vulnerability/resilience to stress in adults. © 2013 the authors.

Apicella F.,Stella Maris Scientific Institute | Sicca F.,Stella Maris Scientific Institute | Federico R.R.,University of Pisa | Campatelli G.,Stella Maris Scientific Institute | And 2 more authors.
Behavioural Brain Research | Year: 2013

Face processing is a neural mechanism that allows understanding social information and cues conveyed by faces, whose dysfunction has been postulated to underlie some of the behavioral impairments characterizing Autism Spectrum Disorders (ASD). A special region of the cortex, the Fusiform Gyrus (FG), is believed to be the specific area for processing face features and emotions. However, behavioral, fMRI and ERP studies addressed to investigate the role of FG dysfunction in ASD have led to conflicting results. Using a high-density EEG system, we recorded the face-sensitive ERP to neutral and emotional (happiness and fearful) faces, as a measure of early activity of the FG, in children with high functioning ASD. By controlling a number of experimental and clinical variables that could have biased previous research - such as gaze direction, attention to tasks, stimulus appearance and clinical profiles - we aimed to assess the effective role of the FG in the face emotion processing deficit hypothesized in ASD. No significant differences in early face-sensitive ERP components were found between ASD and neurotypical children. However, a systematic latency delay and amplitude reduction of all early potentials were observed in the ASD group, regardless of the stimulus, although more evident for emotions. Therefore, we can assume a diffuse dysfunction of neural mechanisms and networks in driving and integrating social information conveyed by faces, in particular when emotions are involved, rather than a specific impairment of the FG-related face processing circuit. Nevertheless, there is need of further investigation. © 2012 Elsevier B.V..

Castaldi E.,University of Florence | Frijia F.,CNR Institute of Neuroscience | Montanaro D.,CNR Institute of Neuroscience | Tosetti M.,Stella Maris Scientific Institute | And 2 more authors.
European Journal of Neuroscience | Year: 2013

Animal physiological and human psychophysical studies suggest that an early step in visual processing involves the detection and identification of features such as lines and edges, by neural mechanisms with even- and odd-symmetric receptive fields. Functional imaging studies also demonstrate mechanisms with even- and odd-receptive fields in early visual areas, in response to luminance-modulated stimuli. In this study we measured fMRI BOLD responses to 2-D stimuli composed of only even or only odd symmetric features, and to an amplitude-matched random noise control, modulated in red-green equiluminant colour contrast. All these stimuli had identical power but different phase spectra, either highly congruent (even or odd symmetry stimuli) or random (noise). At equiluminance, V1 BOLD activity showed no preference between congruent- and random-phase stimuli, as well as no preference between even and odd symmetric stimuli. Areas higher in the visual hierarchy, both along the dorsal pathway (caudal part of the intraparietal sulcus, dorsal LO and V3A) and the ventral pathway (V4), responded preferentially to odd symmetry over even symmetry stimuli, and to congruent over random phase stimuli. Interestingly, V1 showed an equal increase in BOLD activity at each alternation between stimuli of different symmetry, suggesting the existence of specialised mechanisms for the detection of edges and lines such as even- and odd-chromatic receptive fields. Overall the results indicate a high selectivity of colour-selective neurons to spatial phase along both the dorsal and the ventral pathways in humans. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons.

Gori M.,Italian Institute of Technology | Tinelli F.,Stella Maris Scientific Institute | Tinelli F.,University of Florence | Sandini G.,Italian Institute of Technology | And 4 more authors.
Neuropsychologia | Year: 2012

Multisensory integration of spatial information occurs late in childhood, at around eight years (Gori, Del Viva, Sandini, & Burr, 2008). For younger children, the haptic system dominates size discrimination and vision dominates orientation discrimination: the dominance may reflect sensory calibration, and could have direct consequences on children born with specific sensory disabilities. Here we measure thresholds for visual discrimination of orientation and size in children with movement disorders of upper limbs. Visual orientation discrimination was very similar to the age-matched typical children, but visual size discrimination thresholds were far worse, in all eight individuals with early-onset movement disorder. This surprising and counterintuitive result is readily explained by the cross-sensory calibration hypothesis: when the haptic sense is unavailable for manipulation, it cannot be readily used to estimate size, and hence to calibrate the visual experience of size: visual discrimination is subsequently impaired. This complements a previous study showing that non-sighted children have reduced acuity for haptic orientation, but not haptic size, discriminations (Gori, Sandini, Martinoli, & Burr, 2010). Together these studies show that when either vision or haptic manipulation is impaired, the impairment also impacts on complementary sensory systems that are calibrated by that one. © 2012 Elsevier Ltd.

Belmonti V.,Stella Maris Scientific Institute | Belmonti V.,University of Pisa | Cioni G.,Stella Maris Scientific Institute | Cioni G.,University of Pisa | Berthoz A.,Collège de France
Experimental Brain Research | Year: 2013

In goal-oriented locomotion, healthy adults generate highly stereotyped trajectories and a consistent anticipatory head orienting behaviour, both evidence of top-down, open-loop control. The aim of this study is to describe the typical development of anticipatory orienting strategies and trajectory formation. Our hypothesis is that full-blown anticipatory control requires advanced navigational skills. Twenty-six healthy subjects (14 children: 4-11 years; 6 adolescents: 13-17 years; 6 adults) were asked to walk freely towards one of the three visual targets, in a randomised order. Movement was captured via an optoelectronic system, with 15 body markers. The whole-body displacement, yaw orientation of head, trunk and pelvis, heading direction and foot placements were extracted. Head-heading anticipation, trajectory curvature, indexes of variability of trajectories, foot placements and kinematic profiles were studied. The mean head-heading anticipation time and trajectory curvature did not significantly differ among age groups. In children, however, head anticipation was more often lacking (χ 2 = 9.55, p < 0.01), and there were significant intra- and inter-subject variations. Trajectory curvature was often very high in children, while it became consistently lower in adolescence (χ 2 = 78.59, p < 10-17). The indexes of spatial and kinematic variability all followed a decreasing developmental trend (R 2 > 0.5, p < 0.0001). In conclusion, children under 11 do not perform curvilinear locomotor trajectories as adolescents and adults do. Anticipatory head orientation and trajectory formation develop in late childhood, well after gait maturation. Navigational skills, such as path planning and shifting from ego- to allocentric spatial reference frames, are proposed as necessary requisites for mature locomotor control. © 2013 Springer-Verlag Berlin Heidelberg.

Cioni G.,Stella Maris Scientific Institute | Cioni G.,University of Pisa | D'Acunto G.,University of Pisa | Guzzetta A.,Stella Maris Scientific Institute | Guzzetta A.,University of Queensland
Progress in Brain Research | Year: 2011

During the perinatal period, the nervous system is very vulnerable to insult. At this time, the brain undergoes fast and complex maturational processes such as synaptogenesis, arborization, and apoptosis, and the response to the insult is highly dependent on its exact timing. There is evidence that some of the neuroplastic mechanisms adopted by the young brain after damage are unavailable at a later stage of maturation. This applies, for example, to the reorganization of language, the sensorimotor system, or the visual system. Expanding our knowledge on these mechanisms could help the development of early therapeutic interventions aimed at supporting and enhancing functional reorganization at a time of greatest potential brain plasticity. © 2011 Elsevier B.V.

Cosottini M.,IMAGO7 Foundation | Frosini D.,University of Pisa | Pesaresi I.,Neuroradiology Unit | Costagli M.,IMAGO7 Foundation | And 4 more authors.
Radiology | Year: 2014

Purpose: To evaluate the anatomy of the substantia nigra (SN) in healthy subjects by performing 7-T magnetic resonance (MR) imaging of the SN, and to prospectively define the accuracy of 7-T MR imaging in distinguishing Parkinson disease (PD) patients from healthy subjects on an individual basis. Materials and Methods: The 7-T MR imaging protocol was approved by the Italian Ministry of Health and by the local competent ethics committee. SN anatomy was described ex vivo on a gross brain specimen by using highly resolved proton-density (spin-echo proton density) and gradient-recalled-echo (GRE) images, and in vivo in eight healthy subjects (mean age, 40.1 years) by using GRE three-dimensional multiecho susceptibility-weighted images. After training on appearance of SN in eight healthy subjects, the SN anatomy was evaluated twice by two blinded observers in 13 healthy subjects (mean age, 54.7 years) and in 17 PD patients (mean age, 56.9 years). Deviations from normal SN appearance were described and indicated as abnormal, and both diagnostic accuracy and intra-and interobserver agreement for diagnosis of PD with 7-T MR imaging were calculated. Results: Three-dimensional multiecho susceptibility-weighted 7-T MR imaging reveals a three-layered organization of the SN allowing readers to distinguish pars compacta ventralis and dorsalis from pars reticulata. The abnormal architecture of the SN allowed a discrimination between PD patients and healthy subjects with sensitivity and specificity of 100% and 96.2% (range, 92.3%-100%), respectively. Intraobserver agreement (k = 1) and interobserver agreement (k = 0.932) were excellent. Conclusion: MR imaging at 7-T allows a precise characterization of the SN and visualization of its inner organization. Threedimensional multiecho susceptibility-weighted images can be used to accurately differentiate healthy subjects from PD patients, which provides a novel diagnostic opportunity. © 2014 RSNA.

Fiori S.,Stella Maris Scientific Institute | Guzzetta A.,Stella Maris Scientific Institute | Guzzetta A.,University of Pisa
Seminars in Perinatology | Year: 2015

Over the last decade, the application of novel advanced neuroimaging techniques to study congenital brain damage has provided invaluable insights into the mechanisms underlying early neuroplasticity. The concept that is clearly emerging, both from human and nun-human studies, is that functional reorganization in the immature brain is substantially different from that of the more mature, developed brain. This applies to the reorganization of language, the sensorimotor system, and the visual system. The rapid implementation and development of higher order imaging methods will offer increased, currently unavailable knowledge about the specific mechanisms of cerebral plasticity in infancy, which is essential to support the development of early therapeutic interventions aimed at supporting and enhancing functional reorganization during a time of greatest potential brain plasticity. © 2015.

Pooresmaeili A.,Stella Maris Scientific Institute
Journal of vision | Year: 2012

Recently, M. Boi, H. Ogmen, J. Krummenacher, T. U. Otto, & M. H. Herzog (2009) reported a fascinating visual effect, where the direction of apparent motion was disambiguated by cues along the path of apparent motion, the Ternus-Pikler group motion, even though no actual movement occurs in this stimulus. They referred to their study as a "litmus test" to distinguish "non-retinotopic" (motion-based) from "retinotopic" (retina-based) image processing. We adapted the test to one with simple grating stimuli that could be more readily modeled and replicated their psychophysical results quantitatively with this stimulus. We then modeled our experiments in 3D (x, y, t) Fourier space and demonstrated that the observed perceptual effects are readily accounted for by integration of information within a detector that is oriented in space and time, in a similar way to previous explanations of other motion illusions. This demonstration brings the study of Boi et al. into the more general context of perception of moving objects.

Brizzolara D.,Stella Maris Scientific Institute | Brizzolara D.,University of Pisa | Gasperini F.,Stella Maris Scientific Institute | Pfanner L.,Stella Maris Scientific Institute | And 3 more authors.
Cortex | Year: 2011

Specific language impairment (SLI) diagnosed in the pre-school years is frequently associated with reading and writing difficulties at school age. The nature of this relationship is unclear, despite the availability of a large number of studies, mostly on English speaking children. Phonological processing deficits have been considered the prominent cause of both difficulties. However recent findings in both children with SLI and in children with reading difficulties are not easily accommodated within a single dimensional model explaining the relationship between oral and written language deficits.Our study focuses on the long-term reading and spelling outcome in relation to preschool oral language skills in a group of Italian adolescents with a documented history of SLI.Sixteen Italian adolescents diagnosed as SLI at our Hospital in the pre-school years and 32 normal controls were submitted to an extensive assessment of oral and written language skills. At a group level SLI adolescents had weak oral and written language skills in almost all tests.Results show that reading difficulties have some features in common with those of Italian developmental dyslexics but also have distinct characteristics, since reading accuracy and written comprehension, usually relatively spared in Italian developmental dyslexics, were impaired in adolescents with SLI.Longitudinal analyses showed that expressive morpho-syntactic and lexical abilities at pre-school age were the oral language skills that best predicted reading and spelling outcomes in adolescents with SLI.However, also children with severe phonological impairment in the absence of other oral language deficits showed later literacy difficulties, although less severe and mainly limited to reading accuracy.Our study supports the notion that there is a complex relationship between oral and written language difficulties which may change at different developmental time points, not captured by a single deficit model, but best conceptualized considering multiple interactions between language skills and literacy abilities. © 2011 Elsevier Srl.

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