| 1. |
|
|
| 2. |
|
|
| 3. |
- Andin, Josefine, 1979-, et al.
(author)
-
Arithmetic in the adult deaf signing brain
- 2020
-
In: Journal of Neuroscience Research. - : John Wiley & Sons. - 0360-4012 .- 1097-4547. ; 98:4, s. 643-654
-
Journal article (peer-reviewed)abstract
- We have previously shown that deaf signers recruit partially different brain regions during simple arithmetic compared to a group of hearing non-signers, despite similar performance. Specifically, hearing individuals show more widespread activation in brain areas that have been related to the verbal system of numerical processing, i.e., the left angular and inferior frontal gyrus, whereas deaf individuals engaged brain areas that have been related to the quantity system of numerical processing, i.e., the right horizontal intraparietal sulcus. This indicates that compared to hearing non-signers, deaf signers can successfully make use of processes located in partially different brain areas during simple arithmetic. In this study, which is a conceptual replication and extension of the above-presented study, the main aim is to understand similarities and differences in neural correlates supporting arithmetic in deaf compared to hearing individuals. The primary objective is to investigate the role of the right horizontal intraparietal gyrus, the left inferior frontal gyrus, the hippocampus, and the left angular gyrus during simple and difficult arithmetic and how these regions are connected to each other. A second objective is to explore what other brain regions support arithmetic in deaf signers. Up to 34 adult deaf signers and the same amount of hearing non-signers will be enrolled in an functional magnetic resonance imaging study that will include simple and difficult subtraction and multiplication. Brain imaging data will be analyzed using whole-brain analysis, region of interest analysis and connectivity analysis. This is the first study to investigate neural underpinnings of arithmetic of different difficulties in deaf individuals.
|
|
| 4. |
- Andin, Josefine, 1979-, et al.
(author)
-
Arithmetic in the signing brain : Differences and similarities in arithmetic processing between deaf signers and hearing non-signers
- 2023
-
In: Journal of Neuroscience Research. - : John Wiley & Sons. - 0360-4012 .- 1097-4547. ; 101:1, s. 172-195
-
Journal article (peer-reviewed)abstract
- Deaf signers and hearing non-signers have previously been shown to recruit partially different brain regions during simple arithmetic. In light of the triple code model, the differences were interpreted as relating to stronger recruitment of the verbal system of numerical processing, that is, left angular and inferior frontal gyrus, in hearing non-signers, and of the quantity system of numerical processing, that is, right horizontal intraparietal sulcus, for deaf signers. The main aim of the present study was to better understand similarities and differences in the neural correlates supporting arithmetic in deaf compared to hearing individuals. Twenty-nine adult deaf signers and 29 hearing non-signers were enrolled in an functional magnetic resonance imaging study of simple and difficult subtraction and multiplication. Brain imaging data were analyzed using whole-brain analysis, region of interest analysis, and functional connectivity analysis. Although the groups were matched on age, gender, and nonverbal intelligence, the deaf group performed generally poorer than the hearing group in arithmetic. Nevertheless, we found generally similar networks to be involved for both groups, the only exception being the involvement of the left inferior frontal gyrus. This region was activated significantly stronger for the hearing compared to the deaf group but showed stronger functional connectivity with the left superior temporal gyrus in the deaf, compared to the hearing, group. These results lend no support to increased recruitment of the quantity system in deaf signers. Perhaps the reason for performance differences is to be found in other brain regions not included in the original triple code model.
|
|
| 5. |
- Andin, Josefine, 1979-
(author)
-
Biologisk nivå
- 2021
-
In: Att leva som andra. - Lund : Studentlitteratur AB. - 9789144121437 ; , s. 39-66
-
Book chapter (other academic/artistic)
|
|
| 6. |
- Andin, Josefine, 1979-, et al.
(author)
-
fMRI Evidence of Magnitude Manipulation during Numerical Order Processing in Congenitally Deaf Signers
- 2018
-
In: Neural Plasticity. - : HINDAWI LTD. - 2090-5904 .- 1687-5443.
-
Journal article (peer-reviewed)abstract
- Congenital deafness is often compensated by early sign language use leading to typical language development with corresponding neural underpinnings. However, deaf individuals are frequently reported to have poorer numerical abilities than hearing individuals and it is not known whether the underlying neuronal networks differ between groups. In the present study, adult deaf signers and hearing nonsigners performed a digit and letter order tasks, during functional magnetic resonance imaging. We found the neuronal networks recruited in the two tasks to be generally similar across groups, with significant activation in the dorsal visual stream for the letter order task, suggesting letter identification and position encoding. For the digit order task, no significant activation was found for either of the two groups. Region of interest analyses on parietal numerical processing regions revealed different patterns of activation across groups. Importantly, deaf signers showed significant activation in the right horizontal portion of the intraparietal sulcus for the digit order task, suggesting engagement of magnitude manipulation during numerical order processing in this group.
|
|
| 7. |
- Andin, Josefine, 1979-, et al.
(author)
-
Influence of environmental enrichment on steady-state mRNA levels for EAAC1, AMPA1 and NMDA2A receptor subunits in rat hippocampus
- 2007
-
In: Brain Research. - : Elsevier BV. - 0006-8993 .- 1872-6240. ; 1174:1, s. 18-27
-
Journal article (peer-reviewed)abstract
- Interaction with the environment has a key role in refining the neuronal circuitry required for normal brain function throughout life. Profound effects of enriched environment have been shown on neuronal structure and chemistry in experimental animals. Epidemiological studies imply that this is true also in man, thus cognitive stimulation has a protective effect on neurodegeneration, e.g., in Alzheimer's disease. Glutamatergic pathways are imperative for cognitive functions, such as memory, learning and long-term potentiation, and relies on the AMPA and NMDA glutamate receptors and the hippocampus, with its specific subregions, is an important anatomical substrate in this. The glutamate signalling is also dependent on a fine-tuned transport system, in the hippocampus primarily achieved by the glutamate transporter EAAC1. In this study we show how environmental enrichment modulates these parts of the glutamatergic system using quantitative in situ hybridisation. This work demonstrates for the first time that environmental enrichment modulates the mRNA expression of EAAC1 which is significantly and region specifically decreased in the hippocampus. We also provide evidence for regional and hemisphere-specific upregulation of NMDA mRNA in the hippocampus after environmental enrichment. The current work also shows that AMPA mRNA of the hippocampus is not per se changed by environmental enrichment in adult animals. Taken together, our results extend the knowledge of the glutamatergic system of specific regions of the hippocampus and its modulation by environmental enrichment and could contribute to the development of strategies aimed at limiting pathological changes associated with glutamatergic dysfunctions. © 2007.
|
|
| 8. |
- Andin, Josefine, 1979-, et al.
(author)
-
Modulation of neuronal glutamate transporter rEAAC1 mRNA expression in rat brain by amitriptyline
- 2004
-
In: Brain Research. Molecular Brain Research. - : Elsevier BV. - 0169-328X .- 1872-6941. ; 126:1, s. 74-77
-
Journal article (peer-reviewed)abstract
- Glutamate transporters regulate the glutamate concentration in the synaptic cleft within the CNS, a regulation required for normal brain function. In several neurological conditions, the amount of glutamate is altered. One reason for the changes in glutamate concentration might be impaired glutamate transporter function. In this study, an in situ hybridisation technique has been used to elucidate changes in mRNA expression of the glutamate transporter, excitatory amino acid carrier 1 (EAAC1), after treatment with the tricyclic antidepressant (TCA) amitriptyline. The results lead to the suggestion that treatment with tricyclic antidepressants leads to changes in the EAAC1 mRNA expression in rat brain suggesting involvement of the glutamate system in the tricyclic treatment of depression.
|
|
| 9. |
- Andin, Josefine, 1979-, et al.
(author)
-
Multiplication engages phonological networks in Broca's area differently for deaf signers and hearing non-signers
- 2012
-
Conference paper (other academic/artistic)abstract
- In hearing individuals, multiplication relies mainly on the phonological loop while subtraction relies on the visuo-spatial sketchpad (VSSP; Lee & Kang, 2002). Little is known about arithmetic neural networks in deaf signers (DS). Since DS often perform worse than hearing non-signers (NH) on arithmetic in general and multiplication in particular (Traxler, 2000), we hypothesized that there are strategic differences between how groups recruit the phonological loop in multiplication, but not in subtraction, leading to differential activation of phonological processing areas in left inferior frontal gyrus (Broca’s area). We investigated this using a blocked fMRI-design in which nine DS and 17 HN matched on age, gender, education and non-verbal intelligence (Raven & Raven, 1998) were tested on tasks of multiplication, subtraction and phonology (rhyme). The contrasts rhyme versus multiplication and rhyme versus subtraction were examined across groups within the region of interest defined by a probability map of Broca’s area (Amunts, 1999). We observed a significant interaction between task (multiplication and rhyme) and group (F = 12.64, p = .034, FWE-corrected), where the HN showed higher activation for rhyme than for multiplication (T = 4.55, p = .001, FWE-corrected) whereas there were no differences in activations between tasks for DS. For subtraction versus rhyme no interaction with group was found. These results suggest that there are differences between DS and HN in the phonology dependent neural networks in Broca’s area used during multiplication, which may be part of the explanation for poorer performance in DS.
|
|
| 10. |
- Andin, Josefine, 1979-
(author)
-
Pharmacological and environmental modulations of the rat glutamatergic system
- 2006
-
Licentiate thesis (other academic/artistic)abstract
- Glutamate is the principal excitatory neurotransmitter in the central nervous system and it is implicated in neural transmission, learning, memory processes and neuronal plasticity. In the glutamatergic synapse two main components are present; the glutamate receptors and the glutamate transporters. The receptors, the NMDA, AMPA, kainite and the metabotroptic receptors, are responsible for conveying neural transmission, including long term potentiation (LTP), synaptic strengthening and modification. The transporters, located to the neuronal membrane and to the membranes of surrounding astrocytes, regulates the extracellular concentration of glutamate and thereby the duration of the synaptic signal.Alterations in both receptor and transporter systems have been suggested to be important in the pathogenesis of several acute and chronic nervous system diseases, such as psychosis, mood disorders, epilepsy, Parkinson's disease and Alzheimer's disease. The pathophysiology of these disorders is not yet completely understood and the involvement of glutamate is unclear. In this thesis we have sought to investigate the role of the glutamatergic system in the treatment of mood disorders and dementia. The antidepressant drug amitriptyline exerts its main effects on the serotonergic and noradrenergic systems and the antidementia drug rivastigmine acts mainly on the cholinergic system. However, given the close relationship between different neurotransmitter systems we have investigated the influence of amitriptyline and rivastigmine on the mRNA expression of the neuronal transporter, EAAC1, in rats. The results showed for the first time an involvement of EAAC1 in amitriptyline and rivastigmine treatment. Amitriptyline induced an acute increase in EAAC1 mRNA expression, which 24 hour after administration returned to baseline levels. Chronic treatment, on the other hand, induces a significant decrease in cortical areas, which we suggest results in enhanced neuronal transmission. Rivastigmine treatment, acute as well as chronic, induced increases in the mRNA expression in hippocampus. We hypothesize that this counteracts the excitotoxic glutamate levels seen in Alzheimer's disease.Further, environmental enrichment has been shown to have beneficial effects on capillary supply, the number of glial cells and dendritic spines, the thickness and weight of cortex, the concentration of cholinesterase, LTP and synaptic strength in animals. It has also been reported that humans that lead an active life have a reduced risk of developing Alzheimer's disease. This suggests that an active and stimulated life may have a protective effect against dementia in man, by creating a cognitive reserve which provides a buffer against brain pathology or age-related changes. We investigated the influence of environmental enrichment on the mRNA expression of NMDA and AMPA receptors and on EAACl and showed for the first time that EAAC1 mRNA is decreased after environmental enrichment. This is probably followed by an increase of glutamate in the synapse, which in turn leads to enhanced neuronal transmission including enhanced memory formation and learning. Furthermore, we confirmed in greater detail previous findings on the upregulation of NMDA mRNA and show that the regulation is regionally and hemisphere specific. We also confirm that AMPA mRNA is not per se changed by environmental enrichment in adult animals.This work provides further evidence about the involvement of the glutamatergic system in affective and cognitive disorders. Improved knowledge of the glutamatergic system will contribute to the development of strategies aimed at limiting pathological changes associated with glutamatergic dysfunctions.
|
|
