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1.
Child Dev ; 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38563146

ABSTRACT

Most language use is displaced, referring to past, future, or hypothetical events, posing the challenge of how children learn what words refer to when the referent is not physically available. One possibility is that iconic cues that imagistically evoke properties of absent referents support learning when referents are displaced. In an audio-visual corpus of caregiver-child dyads, English-speaking caregivers interacted with their children (N = 71, 24-58 months) in contexts in which the objects talked about were either familiar or unfamiliar to the child, and either physically present or displaced. The analysis of the range of vocal, manual, and looking behaviors caregivers produced suggests that caregivers used iconic cues especially in displaced contexts and for unfamiliar objects, using other cues when objects were present.

2.
Obes Surg ; 34(5): 1523-1527, 2024 May.
Article in English | MEDLINE | ID: mdl-38443570

ABSTRACT

PURPOSE: Overly rigid forms of dietary restraint are associated with poorer weight loss outcomes. Dichotomous ("all or nothing") thinking has been shown to mediate this relationship in non-clinical participants, but this finding has yet to be replicated in clinical samples of individuals who have had weight-loss surgery. MATERIALS AND METHODS: A cross-sectional design was used, adopting quantitative questionnaires with 129 individuals who had previously underwent bariatric surgery at least 12 months prior to participation. Bootstrapped mediation analysis was used to establish the mediating role of dichotomous thinking. RESULTS: Eating-specific dichotomous thinking was shown to fully mediate the relationship between dietary restraint and post-surgical weight loss. In contrast, no mediation effect was found for generalised dichotomous thinking. CONCLUSION: Dichotomous thinking specifically about food/eating may play a central role in weight loss maintenance after weight-loss surgery. Pre-surgical assessment of dichotomous thinking, and provision of psychological therapy to think more flexibly about food, is suggested.


Subject(s)
Bariatric Surgery , Obesity, Morbid , Humans , Obesity, Morbid/surgery , Cross-Sectional Studies , Diet , Surveys and Questionnaires , Feeding Behavior/psychology
3.
Int J Speech Lang Pathol ; 26(2): 257-266, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37337670

ABSTRACT

PURPOSE: Semantic fluency is potentially a useful tool for vocabulary assessment in children with vision impairment because it contains no visual test stimuli. It is not known whether in the primary school years children with vision impairment perform more poorly on semantic fluency tasks compared to their sighted peers. METHOD: We compared semantic fluency performance of two groups of 5- to 11-year-old British English speaking children-one group with vision impairment and one without. We also investigated within-group differences in performance, based on severity of vision impairment. We administered one category (animals) to children with vision impairment (n = 45) and sighted children (n = 30). Participants had one minute to respond. Responses were coded for accuracy, error type, clusters, and switches. RESULT: Correct responses increased with age within each group. Groups did not differ significantly on any outcome measure. Severity of vision impairment did not impact task performance. CONCLUSION: Results suggested that semantic fluency performance-at least for the category animals-is not different in children with vision impairment compared to sighted children. Findings also suggest that semantic fluency could be a suitable addition to the tools that speech-language pathologists use to assess language abilities in children with vision impairment.


Subject(s)
Language , Semantics , Child , Humans , Child, Preschool , Vocabulary , Language Tests , Schools , Verbal Behavior/physiology
4.
Nature ; 621(7980): 788-795, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37730989

ABSTRACT

Oxytocin is a neuropeptide that is important for maternal physiology and childcare, including parturition and milk ejection during nursing1-6. Suckling triggers the release of oxytocin, but other sensory cues-specifically, infant cries-can increase the levels of oxytocin in new human mothers7, which indicates that cries can activate hypothalamic oxytocin neurons. Here we describe a neural circuit that routes auditory information about infant vocalizations to mouse oxytocin neurons. We performed in vivo electrophysiological recordings and photometry from identified oxytocin neurons in awake maternal mice that were presented with pup calls. We found that oxytocin neurons responded to pup vocalizations, but not to pure tones, through input from the posterior intralaminar thalamus, and that repetitive thalamic stimulation induced lasting disinhibition of oxytocin neurons. This circuit gates central oxytocin release and maternal behaviour in response to calls, providing a mechanism for the integration of sensory cues from the offspring in maternal endocrine networks to ensure modulation of brain state for efficient parenting.


Subject(s)
Maternal Behavior , Neural Pathways , Neurons , Oxytocin , Vocalization, Animal , Animals , Female , Mice , Cues , Hypothalamus/cytology , Hypothalamus/physiology , Maternal Behavior/physiology , Neurons/metabolism , Oxytocin/metabolism , Photometry , Thalamic Nuclei/physiology , Vocalization, Animal/physiology , Wakefulness
5.
Res Sq ; 2023 Mar 27.
Article in English | MEDLINE | ID: mdl-37034806

ABSTRACT

Oxytocin is a neuropeptide critical for maternal physiology and social behavior, and is thought to be dysregulated in several neuropsychiatric disorders. Despite the biological and neurocognitive importance of oxytocin signaling, methods are lacking to activate oxytocin receptors with high spatiotemporal precision in the brain and peripheral mammalian tissues. Here we developed and validated caged analogs of oxytocin which are functionally inert until cage release is triggered by ultraviolet light. We examined how focal versus global oxytocin application affected oxytocin-driven Ca2+ wave propagation in mouse mammary tissue. We also validated the application of caged oxytocin in the hippocampus and auditory cortex with electrophysiological recordings in vitro, and demonstrated that oxytocin uncaging can accelerate the onset of mouse maternal behavior in vivo. Together, these results demonstrate that optopharmacological control of caged peptides is a robust tool with spatiotemporal precision for modulating neuropeptide signaling throughout the brain and body.

6.
Neuron ; 111(11): 1795-1811.e7, 2023 06 07.
Article in English | MEDLINE | ID: mdl-37023755

ABSTRACT

Neurons in the prefrontal cortex (PFC) can provide top-down regulation of sensory-affective experiences such as pain. Bottom-up modulation of sensory coding in the PFC, however, remains poorly understood. Here, we examined how oxytocin (OT) signaling from the hypothalamus regulates nociceptive coding in the PFC. In vivo time-lapse endoscopic calcium imaging in freely behaving rats showed that OT selectively enhanced population activity in the prelimbic PFC in response to nociceptive inputs. This population response resulted from the reduction of evoked GABAergic inhibition and manifested as elevated functional connectivity involving pain-responsive neurons. Direct inputs from OT-releasing neurons in the paraventricular nucleus (PVN) of the hypothalamus are crucial to maintaining this prefrontal nociceptive response. Activation of the prelimbic PFC by OT or direct optogenetic stimulation of oxytocinergic PVN projections reduced acute and chronic pain. These results suggest that oxytocinergic signaling in the PVN-PFC circuit constitutes a key mechanism to regulate cortical sensory processing.


Subject(s)
Chronic Pain , Paraventricular Hypothalamic Nucleus , Rats , Animals , Paraventricular Hypothalamic Nucleus/metabolism , Oxytocin/metabolism , Hypothalamus/metabolism , Prefrontal Cortex/metabolism
7.
J Speech Lang Hear Res ; 65(9): 3456-3470, 2022 09 12.
Article in English | MEDLINE | ID: mdl-36001863

ABSTRACT

PURPOSE: This study offers the first description of misspellings across elementary school using the Phonological, Orthographic and Morphological Assessment of Spelling (POMAS), a linguistic framework based on Triple Word Form theory, adapted for French (POMAS-FR). It aims to test the "universality" of POMAS and its suitability to track development in French spelling. METHOD: One hundred ninety-four typically developing French children (Grades 1-5) produced a written narrative and words-to-dictation. These were analyzed for productivity and accuracy. Misspellings were then analyzed using POMAS-FR. RESULTS: Productivity and accuracy were better in the later grades. POMAS-FR provided a novel framework for tracking error types in our French sample. The data showed a linear trend for text production, whereby the proportion of phonological errors decreased rapidly in the early grades, while orthographic errors decreased and morphological errors increased throughout elementary school. Words-to-dictation showed a more stable pattern, with a steady decrease in phonological errors, and a stable proportion of orthographic and morphological errors. The specific error types found within each linguistic category are described for both tasks. CONCLUSIONS: The POMAS-FR allowed for the characterization of linguistic knowledge involved in learning to spell French across elementary school. Interplays between different types of linguistic knowledge were evident at all grades. In comparison with other writing systems, French text spelling competence relied heavily on morphological knowledge. These results suggest POMAS may be applied to other orthographic systems. It also highlights the importance of task and word selection for the qualitative evaluation of spelling. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.20520774.


Subject(s)
Language , Phonetics , Child , Humans , Language Tests , Reading , Students , Writing
8.
Front Psychol ; 13: 895880, 2022.
Article in English | MEDLINE | ID: mdl-35664149

ABSTRACT

A key challenge when learning language in naturalistic circumstances is to extract linguistic information from a continuous stream of speech. This study investigates the predictors of such implicit learning among adults exposed to a new language in a new modality (a sign language). Sign-naïve participants (N = 93; British English speakers) were shown a 4-min weather forecast in Swedish Sign Language. Subsequently, we tested their ability to recognise 22 target sign forms that had been viewed in the forecast, amongst 44 distractor signs that had not been viewed. The target items differed in their occurrence frequency in the forecast and in their degree of iconicity. The results revealed that both frequency and iconicity facilitated recognition of target signs cumulatively. The adult mechanism for language learning thus operates similarly on sign and spoken languages as regards frequency, but also exploits modality-salient properties, for example iconicity for sign languages. Individual differences in cognitive skills and language learning background did not predict recognition. The properties of the input thus influenced adults' language learning abilities at first exposure more than individual differences.

9.
J Deaf Stud Deaf Educ ; 26(4): 490-500, 2021 09 15.
Article in English | MEDLINE | ID: mdl-34476479

ABSTRACT

Several studies have reported poor executive function (EF) development in deaf children with subsequent impacts on their social and academic attainment. This paper describes the results of a music-based EF intervention designed for deaf children and carried out in two sets of primary schools. This is the first classroom-based EF training study with deaf children, and it also incorporates a replication phase. The intervention was a within-subject crossover design, with 29 deaf children aged 7-11 years who participated in both an EF and an art class control activity, each lasting 10 hours over 5 weeks. Non-verbal EF skills were assessed at pre-test, the crossover point, and post-test. Findings indicated that the EF intervention led to an improvement in participants' working memory and inhibitory skills in comparison with their performance on the same tasks after the control activity. The findings were not uniform for all EFs targeted nor for all cognitive ability levels in the sample. We discuss the implications of our findings for deaf children with different ability levels and for how EF interventions can be further improved.


Subject(s)
Music Therapy , Music , Child , Executive Function , Humans , Memory, Short-Term , Schools
10.
Nature ; 596(7873): 553-557, 2021 08.
Article in English | MEDLINE | ID: mdl-34381215

ABSTRACT

Maternal care, including by non-biological parents, is important for offspring survival1-8. Oxytocin1,2,9-15, which is released by the hypothalamic paraventricular nucleus (PVN), is a critical maternal hormone. In mice, oxytocin enables neuroplasticity in the auditory cortex for maternal recognition of pup distress15. However, it is unclear how initial parental experience promotes hypothalamic signalling and cortical plasticity for reliable maternal care. Here we continuously monitored the behaviour of female virgin mice co-housed with an experienced mother and litter. This documentary approach was synchronized with neural recordings from the virgin PVN, including oxytocin neurons. These cells were activated as virgins were enlisted in maternal care by experienced mothers, who shepherded virgins into the nest and demonstrated pup retrieval. Virgins visually observed maternal retrieval, which activated PVN oxytocin neurons and promoted alloparenting. Thus rodents can acquire maternal behaviour by social transmission, providing a mechanism for adapting the brains of adult caregivers to infant needs via endogenous oxytocin.


Subject(s)
Learning , Maternal Behavior/psychology , Mothers/psychology , Neurons/metabolism , Oxytocin/metabolism , Paraventricular Hypothalamic Nucleus/cytology , Sexual Abstinence/psychology , Teaching , Animals , Female , Housing, Animal , Litter Size , Mice , Nesting Behavior , Neuronal Plasticity
11.
PLoS One ; 16(5): e0251050, 2021.
Article in English | MEDLINE | ID: mdl-33979380

ABSTRACT

Some deaf children continue to show difficulties in spoken language learning after cochlear implantation. Part of this variability has been attributed to poor implicit learning skills. However, the involvement of other processes (e.g. verbal rehearsal) has been underestimated in studies that show implicit learning deficits in the deaf population. In this study, we investigated the relationship between auditory deprivation and implicit learning of temporal regularities with a novel task specifically designed to limit the load on working memory, the amount of information processing, and the visual-motor integration skills required. Seventeen deaf children with cochlear implants and eighteen typically hearing children aged 5 to 11 years participated. Our results revealed comparable implicit learning skills between the two groups, suggesting that implicit learning might be resilient to a lack of early auditory stimulation. No significant correlation was found between implicit learning and language tasks. However, deaf children's performance suggests some weaknesses in inhibitory control.


Subject(s)
Education of Hearing Disabled/methods , Learning/physiology , Memory, Short-Term/physiology , Child , Child, Preschool , Cochlear Implantation/education , Cochlear Implantation/psychology , Cochlear Implants/psychology , Deafness/surgery , Female , Hearing/physiology , Humans , Language , Language Development , Male , Memory/physiology , Persons With Hearing Impairments/psychology , Speech/physiology
12.
Dev Sci ; 24(3): e13066, 2021 05.
Article in English | MEDLINE | ID: mdl-33231339

ABSTRACT

A key question in developmental research concerns how children learn associations between words and meanings in their early language development. Given a vast array of possible referents, how does the child know what a word refers to? We contend that onomatopoeia (e.g. knock, meow), where a word's sound evokes the sound properties associated with its meaning, are particularly useful in children's early vocabulary development, offering a link between word and sensory experience not present in arbitrary forms. We suggest that, because onomatopoeia evoke imagery of the referent, children can draw from sensory experience to easily link onomatopoeic words to meaning, both when the referent is present as well as when it is absent. We use two sources of data: naturalistic observations of English-speaking caregiver-child interactions from 14 up to 54 months, to establish whether these words are present early in caregivers' speech to children, and experimental data to test whether English-speaking children can learn from onomatopoeia when it is present. Our results demonstrate that onomatopoeia: (a) are most prevalent in early child-directed language and in children's early productions, (b) are learnt more easily by children compared with non-iconic forms and (c) are used by caregivers in contexts where they can support communication and facilitate word learning.


Subject(s)
Language Development , Symbolism , Child , Humans , Language , Verbal Learning , Vocabulary
13.
Nature ; 587(7834): E2, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33154579

ABSTRACT

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

14.
Nature ; 587(7834): 426-431, 2020 11.
Article in English | MEDLINE | ID: mdl-33029014

ABSTRACT

Infant cries evoke powerful responses in parents1-4. Whether parental animals are intrinsically sensitive to neonatal vocalizations, or instead learn about vocal cues for parenting responses is unclear. In mice, pup-naive virgin females do not recognize the meaning of pup distress calls, but retrieve isolated pups to the nest after having been co-housed with a mother and litter5-9. Distress calls are variable, and require co-caring virgin mice to generalize across calls for reliable retrieval10,11. Here we show that the onset of maternal behaviour in mice results from interactions between intrinsic mechanisms and experience-dependent plasticity in the auditory cortex. In maternal females, calls with inter-syllable intervals (ISIs) from 75 to 375 milliseconds elicited pup retrieval, and cortical responses were generalized across these ISIs. By contrast, naive virgins were neuronally and behaviourally sensitized to the most common ('prototypical') ISIs. Inhibitory and excitatory neural responses were initially mismatched in the cortex of naive mice, with untuned inhibition and overly narrow excitation. During co-housing experiments, excitatory responses broadened to represent a wider range of ISIs, whereas inhibitory tuning sharpened to form a perceptual boundary. We presented synthetic calls during co-housing and observed that neurobehavioural responses adjusted to match these statistics, a process that required cortical activity and the hypothalamic oxytocin system. Neuroplastic mechanisms therefore build on an intrinsic sensitivity in the mouse auditory cortex, and enable rapid plasticity for reliable parenting behaviour.


Subject(s)
Auditory Cortex/physiology , Maternal Behavior/physiology , Neuronal Plasticity/physiology , Acoustic Stimulation , Animals , Auditory Cortex/cytology , Excitatory Postsynaptic Potentials , Female , Housing, Animal , Maternal Behavior/psychology , Mice , Neural Inhibition/physiology , Oxytocin/metabolism , Synapses/metabolism , Time Factors , Vocalization, Animal
15.
Front Psychol ; 11: 1789, 2020.
Article in English | MEDLINE | ID: mdl-32793078

ABSTRACT

Children with Developmental Language Disorder (DLD) often struggle learning to spell. However, it is still unclear where their spelling difficulties lie, and whether they reflect on-going difficulties with specific linguistic domains. It is also unclear whether the spelling profiles of these children vary in different orthographies. The present study compares the spelling profiles of monolingual children with DLD in France and England at the end of primary school. By contrasting these cohorts, we explored the linguistic constraints that affect spelling, beyond phono-graphemic transparency, in two opaque orthographies. Seventeen French and 17 English children with DLD were compared to typically developing children matched for age or spelling level. Participants wrote a 5 min sample of free writing and spelled 12 controlled dictated words. Spelling errors were analyzed to capture areas of difficulty in each language, in the phonological, morphological, orthographic and semantic domains. Overall, the nature of the errors produced by children with DLD is representative of their spelling level in both languages. However, areas of difficulty vary with the language and task, with more morphological errors in French than in English across both tasks and more orthographic errors in English than in French dictated words. The error types produced by children with DLD also differed in the two languages: segmentation and contraction errors were found in French, whilst morphological ending errors were found in English. It is hypothesized that these differences reflect the phonological salience of the units misspelled in both languages. The present study also provides a detailed breakdown of the spelling errors found in both languages for children with DLD and typical peers aged 5-11.

16.
Child Dev ; 91(2): e400-e414, 2020 03.
Article in English | MEDLINE | ID: mdl-30740665

ABSTRACT

Numerous studies suggest an association between language and executive function (EF), but evidence of a developmental relationship remains inconclusive. Data were collected from 75 deaf/hard-of-hearing (DHH) children and 82 hearing age-matched controls. Children were 6-11 years old at first time of testing and completed a battery of nonverbal EF tasks and a test of expressive vocabulary. These tasks were completed again 2 years later. Both groups improved their scores on all tasks over this period. DHH children performed significantly less well than hearing peers on some EF tasks and the vocabulary test at both time points. Cross-lagged panel models showed that vocabulary at Time 1 predicted change in EF scores for both DHH and hearing children but not the reverse.


Subject(s)
Deafness/psychology , Executive Function , Verbal Behavior , Vocabulary , Child , Child, Preschool , Female , Hearing , Humans , Language Development , Language Tests , Longitudinal Studies , Male , Peer Group , Reference Values
17.
Int J Lang Commun Disord ; 55(2): 200-215, 2020 03.
Article in English | MEDLINE | ID: mdl-31697020

ABSTRACT

BACKGROUND: Children with dyslexia and/or developmental language disorder (hereafter children with DDLD) have been reported to retrieve fewer words than their typically developing (TD) peers in semantic fluency tasks. It is not known whether this retrieval difficulty can be attributed to the semantic structure of their lexicon being poor or, alternatively, to words being retrieved more slowly despite semantic structure being intact. AIMS: To test two theoretical models that could potentially account for retrieval difficulties in semantic fluency tasks, namely, the Poor Lexical-Semantic Structure Model and the Slow-Retrieval Model. Both models predict that children with DDLD will retrieve fewer items compared with TD children. However, while the Poor Lexical-Semantic Structure Model predicts a less sophisticated network of semantic connections between words in the lexicon, as evidenced by smaller clusters of related items in children with DDLD, the Slow-Retrieval Model predicts intact inter-item associations in the lexicon, as evidenced by the two groups' clusters being of a similar size. The groups' semantic fluency performance was therefore compared. How semantic fluency performance related to children's language, literacy, and phonological skills was also investigated. METHODS & PROCEDURES: A total of 66 children with DDLD aged 7-12 years and 83 TD children aged 6-12 years, all monolingual Greek speakers, were tested on semantic fluency, using the categories 'animals', 'foods' and 'objects from around the house'. The numbers of correct and incorrect responses, clusters and switches, and the average cluster size were computed. Children were also assessed on non-verbal IQ, language, literacy and phonological tasks. OUTCOMES & RESULTS: In both groups, productivity in semantic fluency tasks correlated strongly with the numbers of clusters and switches, but not with average cluster size. The DDLD group produced significantly fewer correct responses and fewer clusters compared with the TD group, but the two groups showed similar switching and average cluster size. Children's language, literacy and phonological skills significantly predicted the number of correct responses produced, beyond the significant effect of age. CONCLUSIONS & IMPLICATIONS: We conclude that poorer semantic fluency performance in children with DDLD results not from a lexicon with poor semantic structure, but rather from slower retrieval processes from a lexicon with intact semantic structure. The underlying causes of slow lexical retrieval still need further investigation.


Subject(s)
Dyslexia/psychology , Language Development Disorders/psychology , Semantics , Child , Female , Humans , Language Tests , Male
18.
Cell Rep ; 29(6): 1419-1428.e5, 2019 11 05.
Article in English | MEDLINE | ID: mdl-31693884

ABSTRACT

One long-standing model of striatal function divides the striatum into compartments called striosome and matrix. While some anatomical evidence suggests that these populations represent distinct striatal pathways with differing inputs and outputs, functional investigation has been limited by the methods for identifying and manipulating these populations. Here, we utilize hs599CreER mice as a new tool for targeting striosome projection neurons and testing their functional connectivity. Extending anatomical work, we demonstrate that striosome neurons receive greater synaptic input from prelimbic cortex, whereas matrix neurons receive greater input from primary motor cortex. We also identify functional differences in how striosome and matrix neurons process excitatory input, providing the first electrophysiological method for delineating striatal output neuron subtypes. Lastly, we provide the first functional demonstration that striosome neurons are the predominant striatal output to substantia nigra pars compacta dopamine neurons. These results identify striosome and matrix as functionally distinct striatal pathways.


Subject(s)
Corpus Striatum/physiology , Dopaminergic Neurons/physiology , Motor Cortex/physiology , Neural Pathways/physiology , Neurogenesis , Prefrontal Cortex/physiology , Animals , Corpus Striatum/embryology , Corpus Striatum/metabolism , Dopaminergic Neurons/cytology , Dopaminergic Neurons/drug effects , Dopaminergic Neurons/metabolism , Mice , Mice, Transgenic , Motor Cortex/cytology , Motor Cortex/metabolism , Neurogenesis/drug effects , Prefrontal Cortex/cytology , Prefrontal Cortex/metabolism , Substantia Nigra/cytology , Substantia Nigra/metabolism , Substantia Nigra/physiology
19.
Front Psychol ; 10: 638, 2019.
Article in English | MEDLINE | ID: mdl-31031666

ABSTRACT

It is well-established that children with dyslexia and/or Developmental Language Disorder (hereafter children with DDLD) perform poorly on phonological tasks compared to typically developing (TD) children. However, there has been some debate as to whether their phonological deficit arises directly from an impairment in phonological representations, or instead from deficient access to (intact) phonological representations. This study tested the Degraded Phonological Representations Hypothesis and the Deficient Phonological Access Hypothesis using a task that is not often used with children with DDLD, namely phonological fluency. Both hypotheses predict that children with DDLD will retrieve fewer items than their TD peers in the phonological fluency task. However, while the Degraded Phonological Representations Hypothesis predicts smaller clusters of phonologically related items in children with DDLD, the Deficient Phonological Access Hypothesis predicts that the two groups will not differ in cluster size. How phonological fluency performance related to children's language, literacy, and phonological skills was investigated. Further, the specificity of a phonological fluency deficit in children with DDLD was tested using a nonverbal (design) fluency task. Sixty-six children with DDLD aged 7-12 years and 83 TD children aged 6-12 years, all monolingual Greek speakers, were tested on three phonological fluency categories, on nonverbal IQ, language, literacy, and phonological tasks, and on a design fluency task. The DDLD group produced significantly fewer correct responses and fewer switches compared to the TD group, but the two groups showed similar clustering and average cluster size. After controlling for age, children's language, literacy, and phonological skills significantly predicted the number of correct responses produced. The two groups did not differ significantly on the number of unique designs generated in the design fluency task. Furthermore, children with DDLD showed poorer phonological fluency performance relative to their TD peers even after design fluency performance was controlled, demonstrating the specificity of their phonological fluency deficit. This study adds to the theoretical debate on the locus of the phonological deficit in dyslexia and DLD. The findings support the hypothesis that the phonological deficit in dyslexia and DLD lies in deficient explicit access to intact phonological representations.

20.
Cell Rep ; 23(12): 3438-3446.e5, 2018 06 19.
Article in English | MEDLINE | ID: mdl-29924988

ABSTRACT

Action selection relies on the coordinated activity of striatal direct and indirect pathway medium spiny neurons (dMSNs and iMSNs, respectively). Loss of dopamine in Parkinson's disease is thought to disrupt this balance. While dopamine replacement with levodopa may restore normal function, the development of involuntary movements (levodopa-induced dyskinesia [LID]) limits therapy. How chronic dopamine loss and replacement with levodopa modulate the firing of identified MSNs in behaving animals is unknown. Using optogenetically labeled striatal single-unit recordings, we assess circuit dysfunction in parkinsonism and LID. Counter to current models, we found that following dopamine depletion, iMSN firing was elevated only during periods of immobility, while dMSN firing was dramatically and persistently reduced. Most notably, we identified a subpopulation of dMSNs with abnormally high levodopa-evoked firing rates, which correlated specifically with dyskinesia. These findings provide key insights into the circuit mechanisms underlying parkinsonism and LID, with implications for developing targeted therapies.


Subject(s)
Corpus Striatum/pathology , Dyskinesia, Drug-Induced/pathology , Levodopa/adverse effects , Parkinsonian Disorders/pathology , Action Potentials , Animals , Behavior, Animal , Corpus Striatum/physiopathology , Dopamine/metabolism , Dopamine Agonists/pharmacology , Dyskinesia, Drug-Induced/physiopathology , Mice, Inbred C57BL , Mice, Transgenic , Motor Activity/drug effects , Neurons/pathology , Optogenetics , Parkinsonian Disorders/physiopathology , Receptors, Dopamine/metabolism
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