Brain Struct Funct Research Articles

A new 3D myeloarchitectonic map of the human neocortex based on data from the Vogt–Vogt school

During the period extending from 1900 to 1970, Oskar and Cécile Vogt and their numerous collaborators (‘the Vogt–Vogt school’) published a large number of studies on the myeloarchitecture of the human cerebral cortex. During the last decade, we have concerned ourselves with a detailed meta-analysis of these now almost totally forgotten studies, with the aim to bringing them into the modern era of science. This scrutiny yielded inter alia a myeloarchitectonic map of the human neocortex, showing a parcellation into 182 areas (Nieuwenhuys et al. in Brain Struct Funct 220:2551–2573, 2015; Erratum in Brain Struct Funct 220: 3753–3755, 2015). This map, termed 2D’15, which is based on data derived from all of the 20 publications constituting the myeloarchitectonic legacy of the Vogt–Vogt school, has the limitation that it is two-dimensional i.e. it shows only the parts of the cortex exposed at the free surface of the cerebral hemispheres and not the extensive stretches of cortex hidden in the cortical sulci. However, a limited set of data, derived from four of the 20 publications available, has enabled us to create a 3D map, showing the myeloarchitectonic parcellation of the entire human neocortex. This map, designated as 3D′23, contains 182 areas: 64 frontal, 30 parietal, 6 insular, 19 occipital and 63 temporal. We have also prepared a 2D version (2D′23), of this 3D′23 map to serve as a link between the latter and our original 2D′15 map. Detailed comparison of the parcellations visualized in our three maps (2D′15, 2D′23 and 3D′23) warrants the conclusion that our new 3D′23 map may be considered as representative for the entire myeloarchitectural legacy of the Vogt–Vogt School. Hence it is now possible to compare the rich amount of myeloarchitectonic data assembled by that school directly with the results of current 3D analyses of the architecture of the human cortex, such as the meticulous quantitative cyto- and receptor architectonic studies of Zilles, Amunts and their numerous associates (Amunts et al. in Science 369:988–992, 2020), and the multimodal parcellation of the human cortex based on magnetic resonance images from the Human Connectome Project, performed by Glasser et al. in Nature 536:171–178, 2016).

An Insula-Enriched Regulator of Retinoic Acid Marks a New Intersection in the Neural Circuitry of Mouse Social Behavior

An Insula-Enriched Regulator of Retinoic Acid Marks a New Intersection in the Neural Circuitry of Mouse Social Behavior

FV 17 Wallerian degeneration of descending fiber tracts explains motor impairment after stroke

Introduction: Structural changes post-stroke have frequently been assessed using diffusion tensor imaging (DTI). While the microstructural integrity of various parts of the corticospinal tract (CST) has been linked to motor impairment 1 , it remains unclear whether the reduction in anisotropy can be attributed to descending or crossing fibers within the CST. To address this question, we used diffusion spectrum imaging (DSI), an advanced imaging approach that overcomes the shortcomings of DTI, and delineated the influence of CST-inherent crossing and descending fibers. Patients and Methods: DSI scans of 25 chronic stroke patients (mean age=66.7, sd=11.2) and 22 age-matched controls were corrected for motion-and distortion artifacts, reconstructed, and normalized using QSIPrep 2 . Lesion and individual white matter (WM) masks were applied to the resulting generalized fractional anisotropy (gfa)-maps, focusing the analysis on secondary degeneration in WM-tracts. A deterministic mask containing the number of trackable directions per voxel 3 was applied to compartmentalize whole-brain gfa-values. Compartment-wise mean gfa was extracted from motor tracts as defined in the HCP tractography atlas 4 . Using these values, we tested for differences between patients and controls and for an association with upper and lower limb motor impairment. Results: Patients featured reduced gfa-values within the affected CST compared to age-matched controls (t(45)=-3.35, p=.002). This difference was mainly attributable to voxels containing only one fiber direction (t(45)=-3.92, p<.001), i.e., descending fibers, while voxels containing two directions, i.e., crossing fibers, showed no difference (p>0.4). Mean gfa of the affected CST significantly explained upper limb impairment (R 2 =0.30, p=.005), especially for patients suffering from persistent motor deficits (R 2 =0.43, p=.01). This association was driven by unidirectional (R 2 =0.26, p=.009) and not multidirectional voxels (p>0.3). Mean-gfa within the rubrospinal tract was related to persisting lower limb deficits. Conclusion: Anisotropy measures of the CST derived from DSI were significantly reduced and explained upper limb motor impairment in chronic stroke patients. These findings were driven by voxels containing a single fiber direction suggesting that changes in microstructural integrity of motor pathways assessed via diffusion imaging originate from Wallerian degeneration of descending fibers. In non-fully recovered stroke patients with CST damage, extrapyramidal pathways such as the rubrospinal tract may contribute to leg movements, potentially reflecting a compensatory mechanism after CST damage. Our findings underline the potential of DSI to predict motor outcome, especially when focusing the analysis on descending fibers via compartmentalization. References 1 Koch et al., 2016, Annals Clin Transl Neurol. 2 Cieslak et al., 2021, Nature Methods. 3 Volz et al., 2018, Brain Struct Funct. 4 Yeh et al., 2018, NeuroImage.

Opioids and obstructive sleep apnea.

Freire C, Sennes LU, Polotsky VY. Opioids and obstructive sleep apnea. J Clin Sleep Med. 2022;18(2):647-652.

Creativity in nursing

British Journal of Cardiac NursingVol. 15, No. 12 EditorialCreativity in nursingAysha MendesAysha MendesCorrespondence to: Aysha Mendes; E-mail Address: [email protected]British Journal of Cardiac Nursing, MA Healthcare Ltd, London, UKSearch for more papers by this authorAysha MendesPublished Online:22 Dec 2020https://doi.org/10.12968/bjca.2020.0165AboutSectionsView articleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InEmail View article References Centre for Educational Neuroscience. Left brain versus right brain thinkers. n.d. http://www.educationalneuroscience.org.uk/resources/neuromyth-or-neurofact/left-brain-versus-right-brain-thinkers/ (accessed 16 December 2020) Google ScholarEknoyan G. Michelangelo: art, anatomy, and the kidney. Kidney Int. 2000;57(3):1190–1201. https://doi.org/10.1046/j.1523-1755.2000.00947.x Crossref, Google ScholarGermann J, Petrides M, Chakravarty MM. Hand preference and local asymmetry in cerebral cortex, basal ganglia, and cerebellar white matter. Brain Struct Funct. 2019;224:2899–2905. https://doi.org/10.1007/s00429-019-01941-6 Crossref, Google ScholarRana Z. Einstein was an artist: how creativity actually works. 2018. https://tinyurl.com/yan29bcl (accessed 16 December 2020) Google Scholar FiguresReferencesRelatedDetailsCited bySupporting cardiac patients during the COVID-19 pandemicSusan Dawkes9 May 2020 | British Journal of Cardiac Nursing, Vol. 15, No. 5Nurses in isolation, and the dark clouds and silver linings revealed by COVID-19Helen Cowan, Lucy Mason, Emma Wilson28 May 2020 | British Journal of Cardiac Nursing, Vol. 15, No. 5 2 December 2020Volume 15Issue 12ISSN (online): 2052-2207 Metrics History Published online 22 December 2020 Published in print 2 December 2020 Information© MA Healthcare LimitedPDF download

A detailed comparison of the cytoarchitectonic and myeloarchitectonic maps of the human neocortex produced by the Vogt-Vogt school.

The comprehensive research programme of the Vogt-Vogt (V-V) school, which was active during the period 1900-1970, included detailed cytoarchitectonic and myeloarchitectonic analyses of the human cerebral cortex, with the aim to integrate the data obtained into a map, showing a parcellation of the human cerebral cortex into fundamental structural and potentially functional units. The cytoarchitectonic V-V analyses yielded two maps of the human cerebral cortex, the famous map of Brodmann (Vergleichende Lokalisationslehre der Grosshirnrinde in ihren Prinzipien dargestellt auf Grund des Zellenbaues. Barth, Leipzig, 1909), Brodmann (in: Bruns P (ed) Neue deutsche Chirurgie, Enke, Stuttgart, 1914), and the less known, but more detailed map of Sarkisov et al. (Cytoarchitecture of the human cortex cerebri. Medgiz, Moscow, 1949). Sarkisov et al. used in their cytoarchitectonic parcellation of the cortex the same numbering scheme as Brodmann. They confirmed the presence of most of the areas delineated by the latter, but they subdivided several of these areas into two or more separate areas or subareas. Within the realm of the myeloarchitectonic V-V analyses, numerous meticulous studies of the cortex of individual cerebral lobes were carried out, but these were not united into a single map. Consequently, the envisioned integration of cytoarchitectonic and myeloarchitectonic data mentioned above was never realized. Some years ago, we (Nieuwenhuys et al. in Brain Struct Funct 220:2551-2573, 2015a, Nieuwenhuys et al. in Brain Struct Funct 220:3753-3755, 2015b) reanalyzed the V-V myeloarchitectonic data, and succeeded in constructing a complete myeloarchitectonic map of the human neocortex from these data. Because the data provided by the V-V school were derived from many different brains, a standard brain had to be introduced as a template to which all data available could be transferred. As such the MNI305 template was selected. Having made available now the cytoarchitectonic maps of Brodmann and Sarkisov et al. and the recently prepared myeloarchitectonic map, an attempt is made here to realize at last the original aim of the V-V school, viz. the preparation of a single, combined (cyto + myelo) architectonic map of the human cortex. To this end, the following three steps have been made. First, Brodmann's (BR) map, and the map of Sarkisov et al. (SA) were harmoniously transferred to the same template brain as the one used during the construction of our myeloarchitectonic map. Second, the standardized BR and our myeloarchitectonic (NI) map were compared, and the data contained within these maps were integrated into a single standardized combined BR-NI map (Fig.11). The standardized SA and NI maps were subjected to the same procedure (Fig.12). Finally, the standardized combined BR-NI and SA-NI maps were united into a single combined BR-SA-NI map (Fig.13). This map renders it possible to make direct comparisons between the results of the architectonic studies of the V-V school and current parcellations of the human neocortex.

Three divisions of the mouse caudal striatum differ in the proportions of dopamine D1 and D2 receptor-expressing cells, distribution of dopaminergic axons, and composition of cholinergic and GABAergic interneurons

The greater part of the striatum is composed of striosomes and matrix compartments, but we recently demonstrated the presence of a region that has a distinct structural organization in the ventral half of the mouse caudal striatum (Miyamoto et al. in Brain Struct Funct 223:4275–4291, 2018). This region, termed the tri-laminar part based upon its differential immunoreactivities for substance P and enkephalin, consists of medial, intermediate, and lateral divisions. In this study, we quantitatively analyzed the distributions of both projection neurons and interneurons in each division using immunohistochemistry. Two types of projection neurons expressing either the dopamine D1 receptor (D1R) or D2 receptor (D2R) showed complementary distributions throughout the tri-laminar part, but the proportions significantly differed among the three divisions. The proportion of D1R-expressing neurons in the medial, intermediate, and lateral divisions was 88.6 ± 8.2% (651 cells from 3 mice), 14.7 ± 3.8% (1025 cells), and 49.3 ± 4.5% (873 cells), respectively. The intermediate division was further characterized by poor innervation of tyrosine hydroxylase immunoreactive axons. The numerical density of choline acetyltransferase immunoreactive neurons differed among the three divisions following the order from the medial to lateral divisions. In contrast, PV-positive somata were distributed throughout all three divisions at a constant density. Two types of GABAergic interneurons labeled for nitric oxide synthase and calretinin showed the highest cell density in the medial division. The present results characterize the three divisions of the mouse caudal striatum as distinct structures, which will facilitate studies of novel functional loops in the basal ganglia.

A Study of Brain Damage and Compensation in Anomic Aphasia Patients in the Acute Stage Post Stroke, Based on Functional Magnetic Resonance Imaging of a Picture Naming Task

A Study of Brain Damage and Compensation in Anomic Aphasia Patients in the Acute Stage Post Stroke, Based on Functional Magnetic Resonance Imaging of a Picture Naming Task

Physiological underarousal as a mechanism of aggressive behavior in university athletes with a history of concussion.

IntroductionResearch has indicated that athletes who engage in high‐risk athletic activities, such as football and hockey, have riskier personalities than their low‐risk and nonathlete counterparts (Ahmadi et al., 2011, Procedia Soc Behav Sci, 30 and 247–251; Zuckerman, 1983, Biological bases of sensation seeking, impulsivity, and anxiety, Lawrence Erlbaum Assoc Inc.). For instance, increased sensation‐seeking and aggression are common in high‐risk athletes, rendering these individuals more likely to sustain a subsequent injury, such as concussion. Elevated levels of certain personality traits, including impulsivity and aggression, have also been observed after concussion (Goswami et al., 2016, Brain Struct Funct, 221 and 1911–1925). The purpose of this study therefore was to determine whether aggressive behavior in university athletes may be accounted for, in part, by a history of concussion, rather than exclusively athletic status.MethodsUsing a quasi‐experimental design, 66 university students (n = 18 nonathletes, n = 24 low‐risk athletes, n = 24 high‐risk athletes) with (n = 27) and without a history of concussion (n = 39) completed the Buss & Perry Aggression Questionnaire (BPAQ; Buss & Perry, 1992, J Pers Soc Psychol, 63 and 452) and provided electrodermal activation (EDA) as an index of physiological arousal.ResultsIt was found that decreased physiological arousal among students with a history of concussion was associated with greater endorsement of physical aggression. Moreover, athletic status did not account for this pattern of aggression, as athletes and nonathletes did not differ in terms of self‐reported aggressive tendencies.ConclusionsPhysiological compromise after concussive injury may act as an independent mechanism of aggressive behavior in athletes beyond factors, such as athletic status.

S180. MICROSTRUCTURE COMPLEXITY OF THE THALAMUS IN SCHIZOPHRENIA: A NODDI STUDY

BackgroundSchizophrenia is a neurodevelopmental disease arising from complex interactions between genetic and environmental factors that cause disconnectivity within core brain networks including the thalamus. The thalamus has a central role in the pathophysiology of schizophrenia, however to what extent and how it is affected at the microstructural level is still a matter of debate. In the current study, we apply the Neurite Orientation Dispersion and Density Imaging (NODDI) [1], a recently developed MRI technique, which allows the estimation of the microstructural complexity of dendrites and axons in vivo.MethodsTwenty-three patients with schizophrenia (SCHZ) were recruited from the Service of General Psychiatry (Lausanne University Hospital, Switzerland) (40.18 ± 9.2yo; 18/5 males/females) and 27 healthy controls (HC) (37.7 ± 7.95yo; 18/9 males/females). Magnetization-Prepared Rapid Acquisition Gradient Echo (MPRAGE) and a diffusion spectrum imaging (DSI) was performed on a 3-Tesla scanner (MAGNETOM Trio a Tim system, Siemens, Germany). Thalamus segmentation was performed on the MPRAGE sequence with an in house-pipeline using Freesurfer v5.0.0 for segmentation which was then refined to remove voxels within the ventricles and/or overlapping the internal capsule [2]. Orientation Dispersion Index (ODI), Intracellular Volume Fraction (ICVF) and, Isotropic Volume Fraction (ISOVF) were estimated based on the DSI sequence with NODDI [1]. General Linear Models (GLM) were estimated with outcome measures (ICVF, ISOVF, ODI) as dependent variables, group membership as a fixed factor (HC vs. SCHZ) and age and gender as potential covariates.References1Battistella G, Najdenovska E, Maeder P, et al. Robust thalamic nuclei segmentation method based on local diffusion magnetic resonance properties. Brain Struct Funct 2016. DOI:10.1007/s00429-016-1336-4.2Zhang H, Schneider T, Wheeler-kingshott CA, Alexander DC. NeuroImage NODDI : Practical in vivo neurite orientation dispersion and density imaging of the human brain. Neuroimage 2012; 61: 1000–16.ResultsMean ODI was significantly increased in schizophrenia patients compared to controls in the right thalamus (F(1,48)=5.032, p= .030, np2 = .095) and in the left thalamus (F(1,48)=4.500, p= .039, np2 = .086). When controlled for age and gender, the difference remained significant for the right thalamus (F(1, 46) = 4.197, p = .046, np2 = .084) but reduced to trend level for the left thalamus (F(1, 46) = 4.029, p = .051, np2 = .081). There were no significant differences on the other measures (ICVF, ISOVF).DiscussionOur results show that the thalamus is affected in patients with SCHZ at the microstructural level. The observed increase in ODI, which estimates the dispersion of neurite orientations, suggests disrupted neurite organization in patients as compared to HC.

Efferents of anterior cingulate areas 24a and 24b and midcingulate areas 24a' and 24b' in the mouse.

The anterior cingulate cortex (ACC), constituted by areas 25, 32, 24a and 24b in rodents, plays a major role in cognition, emotion and pain. In a previous study, we described the afferents of areas 24a and 24b and those of areas 24a' and 24b' of midcingulate cortex (MCC) in mice and highlighted some density differences among cingulate inputs (Fillinger et al., Brain Struct Funct 222:1509-1532, 2017). To complete this connectome, we analyzed here the efferents of ACC and MCC by injecting anterograde tracers in areas 24a/24b of ACC and 24a'/24b' of MCC. Our results reveal a common projections pattern from both ACC and MCC, targeting the cortical mantle (intracingulate, retrosplenial and parietal associative cortex), the non-cortical basal forebrain, (dorsal striatum, septum, claustrum, basolateral amygdala), the hypothalamus (anterior, lateral, posterior), the thalamus (anterior, laterodorsal, ventral, mediodorsal, midline and intralaminar nuclei), the brainstem (periaqueductal gray, superior colliculus, pontomesencephalic reticular formation, pontine nuclei, tegmental nuclei) and the spinal cord. In addition to an overall denser ACC projection pattern compared to MCC, our analysis revealed clear differences in the density and topography of efferents between ACC and MCC, as well as between dorsal (24b/24b') and ventral (24a/24a') areas, suggesting a common functionality of these two cingulate regions supplemented by specific roles of each area. These results provide a detailed analysis of the efferents of the mouse areas 24a/24b and 24a'/24b' and achieve the description of the cingulate connectome, which bring the anatomical basis necessary to address the roles of ACC and MCC in mice.

Coupling Realistic Computational Neural Model and Human Experimental Data: the Cerebellar Role in Eye Blink Conditioning and its Alteration due to Transcranial Magnetic Stimulation

Coupling Realistic Computational Neural Model and Human Experimental Data: the Cerebellar Role in Eye Blink Conditioning and its Alteration due to Transcranial Magnetic Stimulation

A map of the human neocortex showing the estimated overall myelin content of the individual architectonic areas based on the studies of Adolf Hopf

During the period extending from 1910 to 1970, Oscar and Cécile Vogt and their numerous collaborators published a large number of myeloarchitectonic studies on the cortex of the various lobes of the human cerebrum. In a previous publication [Nieuwenhuys et al (Brain Struct Funct 220:2551–2573, 2015; Erratum in Brain Struct Funct 220: 3753–3755, 2015)], we used the data provided by the Vogt–Vogt school for the composition of a myeloarchitectonic map of the entire human neocortex. Because these data were derived from many different brains, a standard brain had to be introduced to which all data available could be transferred. As such the Colin 27 structural scan, aligned to the MNI305 template was selected. The resultant map includes 180 myeloarchitectonic areas, 64 frontal, 30 parietal, 6 insular, 17 occipital and 63 temporal. Here we present a supplementary map in which the overall density of the myelinated fibers in the individual architectonic areas is indicated, based on a meta-analysis of data provided by Adolf Hopf, a prominent collaborator of the Vogts. This map shows that the primary sensory and motor regions are densely myelinated and that, in general, myelination decreases stepwise with the distance from these primary regions. The map also reveals the presence of a number of heavily myelinated formations, situated beyond the primary sensory and motor domains, each consisting of two or more myeloarchitectonic areas. These formations were provisionally designated as the orbitofrontal, intraparietal, posterolateral temporal, and basal temporal dark clusters. Recently published MRI-based in vivo myelin content mappings show, with regard to the primary sensory and motor regions, a striking concordance with our map. As regards the heavily myelinated clusters shown by our map, scrutiny of the current literature revealed that correlates of all of these clusters have been identified in in vivo structural MRI studies and appear to correspond either entirely or largely to known cytoarchitectonic entities. Moreover, functional neuroimaging studies indicate that all of these clusters are involved in vision-related cognitive functions.

Arborization patterns of amygdalopetal axons from the rat ventral pallidum.

We previously analyzed the arborization patterns of rat ventral pallidal (VP) axons that coursed caudally to innervate the thalamus and brainstem (Tripathi et al. in Brain Struct Funct 218:1133-1157, 2013). Here, we have reconstructed 16 previously undetected axons from the same tracer deposits that follow a more lateral trajectory. Virtually all 16 axons emanating from the different VP compartments collateralized in the extended amygdala system (EAS) and amygdaloid complex. The most frequent targets of axons from the lateral and medial (VPm) VP compartments were the rostral sublenticular extended amygdala, the extended amygdala (EA), the central nucleus of the amygdala and the posterior part of the basolateral amygdaloid nucleus. In contrast, axons from the rostral extension of the VP preferentially innervated the anterior amygdaloid area, the magnocellular preoptic nucleus, and the anterior part of the basomedial amygdaloid nucleus. We additionally found and reconstructed a single corticopetal axon arising from the VPm. The new results show that both direct and indirect projections from the basolateral complex and EAS to the ventral striatopallidal system are reciprocated by VP projections, and suggest that the systems can be activated simultaneously. The results additionally suggest that the amygdaloid complex and cortex are innervated separately from the VP. Finally, the combination of new and previous data indicate that approximately 84% of VP axons (88/105) participate in basal ganglia circuits, 15% (16/105) target the amygdaloid complex, and less than 1% innervate the cortex.

Working Memory Models: Insights From Neuroimaging.

FIGURE 1. The Atkinson and Shiffrin Model of memory is diagramed in the gray panel. Sensory information is perceived and suppressed via selective attention processes, then briefly held in the limited-capacity modality-specific sensory register. Information enhanced by selective attention enters into short term memory (STM). The process of rehearsal (maintenance) can sustain information in STM. Information in STM is automatically encoded (stored, consolidated) into long term memory (LTM). Although flawed, this model continues to provide a simple and easy approach to understanding memory. Assumptions that proved to be inconsistent with research included that any information in STM will transfer to LTM and that STM is required

Insular cortex: structural and functional neuroanatomy.

Insular cortex: structural and functional neuroanatomy.

A new myeloarchitectonic map of the human neocortex based on data from the Vogt-Vogt school.

The human cerebral cortex contains numerous myelinated fibres, the arrangement and density of which is by no means homogeneous throughout the cortex. Local differences in the spatial organization of these fibres render it possible to recognize areas with a different myeloarchitecture. The neuroanatomical subdiscipline aimed at the identification and delineation of such areas is known as myeloarchitectonics. During the period extending from 1910 to 1970, Oscar and Cécile Vogt and their numerous collaborators (The Vogt-Vogt school) published a large number of myeloarchitectonic studies on the cortex of the various lobes of the human cerebrum. Recently, one of us (Nieuwenhuys in Brain Struct Funct 218: 303-352, 2013) extensively reviewed these studies. It was concluded that the data available are adequate and sufficient for the composition of a myeloarchitectonic map of the entire human neocortex. The present paper is devoted to the creation of this map. Because the data provided by the Vogt-Vogt school are derived from many different brains, a standard brain had to be introduced to which all data available could be transferred. As such, the colin27 structural scan, aligned to the MNI305 template was selected. The procedure employed in this transfer involved computer-aided transformations of the lobar maps available in the literature, to the corresponding regions of the standard brain, as well as local adjustments in the border zones of the various lobes. The resultant map includes 180 myeloarchitectonic areas, 64 frontal, 30 parietal, 6 insular, 17 occipital and 63 temporal. The designation of the various areas with simple Arabic numbers, introduced by Oscar Vogt for the frontal and parietal cortices, has been extended over the entire neocortex. It may be expected that combination of the myeloarchitectonic data of the Vogt-Vogt school, as expressed in our map, with the results of the detailed cytoarchitectonic and receptor architectonic studies of Karl Zilles and Katrin Amunts and their numerous associates, will yield a comprehensive 'supermap' of the structural organization of the human neocortex. For the time being, i. e., as long as this 'supermap' is not yet available, our map may provide a tentative frame of reference for (a) the morphological interpretation of the results of functional neuroimaging studies; (b) the selection of starting points (seed voxels, regions-of-interest) in diffusion tractography studies and

Receptor architecture of visual areas in the face and word-form recognition region of the posterior fusiform gyrus

Recently, two extrastriate visual areas on the posterior fusiform gyrus, areas FG1 and FG2, were identified based on cytoarchitectonical criteria (Caspers et al. in Brain Struct Funct 218:511-526, 2013a). They are located within the object-related ventral visual stream at the transition between early and higher-order (category-specific) visual areas. FG2 has a topographical position which is best comparable to the face or visual word-form recognition area. However, the precise function of FG2 is presently unknown. Since transmitter receptors are key molecules of neurotransmission, we analysed the regional and laminar distribution of 15 different receptor binding sites by means of quantitative in vitro receptor autoradiography. Significant differences between receptor densities of both areas were found for NMDA, GABAB, M3, nicotinic α4/β2 and 5-HT1A receptors as well as for GABAA associated benzodiazepine binding sites. These results support the cytoarchitectonic segregation of FG1 and FG2 into two distinct cortical areas. In addition, principal component and hierarchical cluster analyses of the multireceptor data of both fusiform areas and 24 visual, auditory, somatosensory and multimodal association areas not only revealed the typical receptor architectonic characteristics of visual areas for FG1 and FG2, but also suggest their putative function as object recognition regions due to the similarity of their receptor fingerprints with those of areas of the ventral visual stream. Furthermore, FG1 and FG2 build a cluster with the multimodal association areas of the inferior parietal lobule. This underlines their hierarchically high position in the visual system of the human cerebral cortex.

Discordant cerebral lateralisation for verbal fluency is not an artefact of attention: evidence from MzHd twins

The current study investigated how the brain structure-function relationships between covert and overt verbal fluency in monozygotic handedness discordant (MzHd) twins relates to broader attentional measures. Evidence presented here shows that the structure-function correlation demonstrated between functional cerebral lateralisation and corpus callosum widths 22-39, contiguous with Broca's area and the middle frontal gyri (Gurd et al. in Brain Struct Funct 218:491-509, 2013), is not an artefact of attention. Twenty-five pairs of female MzHd twins performed a verbal switching task titrated for number of switches. The paradigm permits calculation of switch rates and costs. The switch rate and cost varied as a function of number of switches (1, 2, 3). There were no differences in any measure in relation to right-left handedness in twin pairs. This was supported by large and significant within-twin pair correlations. Atypical functional lateralisation of inferior and middle frontal lobes does not appear to be associated with better or worse performance on verbal task-switching. Discordant lateralisation for verbal fluency does not predict behavioural performance profiles in MzHd twins. This evidence is compatible with a view that attentional components of verbal fluency task performance may have significant heritable components. It does not indicate that neural correlates of frontal cerebral laterality for verbal fluency in MzHd twins are significantly accountable for by heritable components.

Late-Life Depression Research: Lessons Learned From the Metabolic Syndrome

Late-Life Depression Research: Lessons Learned From the Metabolic Syndrome