Moradi, Z., Najlerahim, A., Macrae, C. N., & Humphreys, G. W. (2020).
There is ample evidence demonstrating intergroup biases on cognition and emotion. However, it remains unclear how exactly group identification influences these processes, with issues of context sensitivity and goal dependence remaining open to scrutiny. Providing a range of interdisciplinary material, the current review attempts to inform understanding of these issues. Specifically, we provide evidence revealing that individuals show enhanced attention for stimuli associated with an ingroup compared to an outgroup. At the attentional level, such biases can be explained by the assignment of different levels of saliency to ingroup versus outgroup targets. Critically, however, salience assignment is not fixed but varies as a function of context and goal-directed behavior. We suggest that the network in the brain previously associated with social and emotional saliency and attention–notably the anterior insula, posterior superior temporal sulcus, and dorsolateral prefrontal cortex–underpins these effects. Moreover, although attention typically favors ingroup targets, outgroup members can be prioritized on occasion. The implications of this viewpoint and future lines of investigation are considered. © ۲۰۲۰, © ۲۰۲۰ Informa UK Limited, trading as Taylor & Francis Group.
Volume 15, Issue 3, 3 May 2020, Pages 324-333
Najlerahim. A., Watson, R.E.B., and Bennet. J.P
Cells containing mRNA for the gamma-aminobutyric acid (GABA) transporter GAT-1 were identified in rat brain by in situ hybridisation. They were found in most of the known locations of GABAergic neurons, as defined by the distribution of mRNA for glutamic acid decarboxylase, the synthetic enzyme for GABA. Within the cerebellum there was substantial labelling of basket and stellate cells in the molecular layer, and of Golgi cells but no others in the granule cell layer. Many Purkinje cells were unlabelled while others, particularly in the hemispheres, were moderately labelled. Many of the Purkinje cells negative for GAT-1 mRNA had adjacent intensely labelled small cells whose size and position corresponded to Bergmann glia. Numerical comparison of cells labelling for GAT-1 mRNA and the mRNAs for the two known isoforms of glutamic acid decarboxylase were made on serial sections of cerebral cortex. Cells positive for GAT-1 mRNA were more numerous, indicating that expression of the transporter is not just limited to GABAergic cells and we suggest that it may also be expressed postsynaptically by some non-GABAergic neurons.
J. Anat. ۱۸۵ (۱۹۹۴) ۳۱۵ -۳۲۳
Najlerahim, A., & Moradi, Z. (2009).
A decline in the ability to process facial expression of emotions has been reported in individuals with Alzheimer’s disease (AD). However, the low number of participants and the lack of diversity in the tasks being used in previous studies leaves a gap in our knowledge about this issue. Gap, we recruited 169 participants including healthy older adults (HOA), participants with mild cognitive impairment (MCI) and AD patients at different stages of the disease (mild to moderate). Four tasks including recognition, selection, matching and declarative knowledge about facial expression of emotions were used. Face identification was used as a control task. Our results revealed that compared with HOA, MCI participants did not show any significant deficits in none of the tasks. AD patients did not show any impairment in the control task. However, they were impaired in the processing of facial expression of negative emotions across all four affective tasks. Interestingly, recognition and selection of happiness were intact in AD patients at the mild stage of the disease. Our findings suggest that despite the pathology affecting distributed areas in the brain, the less challenging aspects (recognition and selection) of the ability to process the facial expression of happiness were preserved at the early stage of the disease. By recruiting a large number of participants together using with several different tasks our study provides a comprehensive picture of the disorders of facial emotion processing in Alzheimer’s Disease. Our findings have significant implications for improving the AD patients’ quality of life and the quality of their social interaction with others. Future studies might start to investigate the processing of emotions in AD patients in other modalities rather than visual
Najlerahim. A
In situ hybridization histochemistry (ISHH) has been used to study the differential distribution and relative abundance of mRNAs encoding a stimulatory alpha subunit of the G-protein (Gs alpha) and glutamic acid decarboxylase (GAD) in the dorsal hippocampus in adult rat brain. The present quantitative study shows that GABAergic neurons containing high levels of GAD mRNA, express considerably more Gs alpha message than excitatory principal neurons, the granule cells of the dentate gyrus and the pyramidal cells of CA1 subfield. A subpopulation of basket cells of the dentate gyrus exhibited a uniquely high level of Gs alpha mRNA, in addition to GAD. These findings may indicate a specific functional role for Gs alpha in these GABAergic neurons in the hippocampus.
Res 18 (1993) 291 – 295
Swan. M., Najlerahim . A., and Pearson, R.C. A
The messenger RNA encoding glutamic acid decarboxylase (GAD) has been examined in the pallidum of the rat using in situ hybridization histochemistry following damage of the striatum and overlying frontal neocortex of one side. Following a postoperative survival time of 5 weeks, ipsilateral shrunken pallidal neurons showed significant decrease in GAD mRNA. The mRNA for GAD is significantly increased in neurons of the contralateral pallidum. These neurons are also significantly enlarged. These findings may be related to pathological changes in pallidal neurons in Huntington’s disease.
Neurol., 118 (1992) 352 -356
Najlerahim, A., Showell, D.G.L., and Pearson, R.C.A
In situ hybridization histochemistry (ISHH) was used to study the expression of glutamic acid decarboxylase (GAD) mRNA changes in the rat cerebral cortex following unilateral frontal and somatosensory cortical lesion by devascularisation. 4 days after the lesion, a significant transient increase in GAD mRNA level in the ipsilateral cortex was observed when compared with contralateral, ipsi-sham operated and ipsi-normal control cortices. The change occurred throughout the ipsilateral neocortex, with no significant difference between the magnitude of increase in frontal, parieto-occipital, parieto-temporal, cingulate or retrosplenial areas; no obvious change was seen in pyriform, entorhinal or hippocampal cortices. This unexpected GAD mRNA increase in neocortex may be part of a long term adaptive functional alteration and changes in the gene expression of the cerebral cortex following focal cortical injury.
Exo brain Res 87 (1991) 113 _118
Najlerahim, A., Harrison, P.J., Barton, A.J.L., Hefferman, J., and Pearson, R.C.A
In situ hybridization histochemistry (ISHH) using synthetic oligonucleotide probes has been used to identify cells containing the mRNAs coding for glutaminase (GluT), aspartate aminotransferase (AspT) and glutamic acid decarboxylase (GAD). The distribution of GAD mRNA confirms previous descriptions and matches the distribution of GAD detected using specific antibodies. AspT mRNA is widely distributed in the brain, but is present at high levels in GABAergic neuronal populations, some that may be glutamatergic, and in a subset of neurons which do not contain significant levels of either GAD or GluT mRNA. Particularly prominent are the neurons of the magnocellular division of the red nucleus, the large cells in the deep cerebellar nuclei and the vestibular nuclei and neurons of the lateral superior olivary nucleus. GluT mRNA does not appear to be present at high levels in all GAD-containing neurons, but is seen prominently in many neuronal populations that may use glutamate as a neurotransmitter, such as neocortical and hippocampal pyramidal cells, the granule cells of the cerebellum and neurons of the dentate gyrus of the hippocampus. The heaviest labelling of GluT mRNA is seen in the lateral reticular nucleus of the medulla. ISHH using probes directed against the mRNAs encoding these enzymes may be an important technique for identifying glutamate and aspartate using neuronal populations and for examining their regulation in a variety of experimental and pathological circumstances.
Mol Brain Res 7 (1990) 317 -333
Najlerahim, A., Barton , A.J.L., Harrison, P.J., Heffernan, J., and Pearson, R.C.A.
A 30 base synthetic oligonucleotide probe was used to detect the mRNA encoding the rat D2 dopaminergic receptor. On Northern analysis, the probe identified a single species of mRNA of approximately 2.9 kb, present at highest levels in the striatum but also found in the brainstem, neocortex and diencephalon. On sections, neurons containing high levels of the mRNA were detected in the striatum, the substantia nigra pars compacta and the ventral tegmental area. Lower levels of signal were seen over neurons in the hypothalamus, the frontal neocortex, and the globus pallidus.
FEBS Lett 255 (1989) 335- 339
Bowen. D.M., Najlerahim, A., Procter, A.W., Francis, P.T., and Murphy, E
The extent and distribution of biochemical abnormalities thought to reflect disorders of subpopulations of neurons have been determined in the cerebral cortex from brains of patients with Alzheimer-type dementia and depressive illness who died of natural causes. In dementia, loss of gray matter from areas of the parietal and temporal lobes is most obvious. In depression, these areas are not affected, but the pars opercularis and temporal pole are smaller than in controls. Results expressed per unit mass of total protein indicate selective reductions in both disorders of serotonin 2 recognition sites in all areas examined and of somatostatin content in only the temporal pole of the six areas examined. In dementia alone a selective loss was found of somatostatin content of the superior parietal lobule and of serotonin 1A sites and choline acetyltransferase activity in all areas examined. Results for depression expressed per entire area indicate additionally reduced somatostatin content and serotonin 1A sites in the pars opercularis and serotonin 1A sites in the temporal pole. These multiple analyses performed on each sample provide further support for a prominent disorder of pyramidal neurons in dementia as well as more evidence for alterations in cortical neurons in depression, either as a result of the disease itself or its treatment.
Acad Sci USA 86 (1989) 9504 _9508
Najlerahim, A., Francis, P., T., and Bowen, , D.M
The excitatory amino acids as neurotransmitters in the neocortex, hippocampus, striatum, thalamus, amygdala, nucleus basalis of Meynert and cerebellum from rats aged 4 months, 12 months and 24 months have been examined by measuring sodium-dependent high affinity uptake of D-[3H]-aspartate into preparations containing synaptosomes. Calcium-dependent K(+)-stimulated release of endogenous glutamate from the nucleus basalis was also measured. The hippocampus and cerebellum failed to show significant age-related changes in uptake of D-[3H]-aspartate. D-[3H]-aspartate uptake decreased significantly in the neocortex (29%), striatum (29%), nucleus basalis (26%), amygdala (19%) and thalamus (16%) in the middle-aged rats as compared to the young rats, but the changes were not progressive with age. The release of glutamate from the nucleus basalis was unaltered during the aging process.
Neurobiol Aging 11 (1990) 1455- 158
Najlerahim , A., and Bowen, D.M
A series of Alzheimer’s disease and control brains were dissected to determine the extent of atrophy (based on total protein content) and loss of choline acetyltransferase activity in the cerebral cortex from the entire surface of the diseased brains. The distribution of intensity of pathology so determined is strikingly similar to the degree of hypometabolism as shown by positron emission tomography. It is argued that the hypometabolism can be explained (at least in part) by focal areas of atrophy.
Biochem J. 251 (1988) 305-308
Najlerahim, A., and Bowen, D.M
All the cerebral cortex and some subcortical nuclei from six examples of senile dementia of the Alzheimer type (SDAT) and six age- and sex-matched controls have been dissected and weighed. The weight of the parietal and temporal cortex are significantly reduced. The parietal lobe shows the largest weight loss and this is most obvious in the precuneus and the superior lobule. The posterior cingulate, the middle and superior temporal, the supramarginal and the superior frontal gyri also show significant weight reduction. Weight loss of the amygdala is more than that of the hippocampus, the caudate nucleus and the putamen, but the weights of all are reduced significantly. These results are rather unexpected but are consistent with other data (e.g. the clinical parietal lobe syndrome and focus of glucose hypometabolism in Alzheimer’s disease). They indicate that prominent changes occur in SDAT in the association areas of the parietal lobe as well as in the amygdala.
Acta Neuropatol. (berl) 75 (1988) 509 -512
