Lateral Pulvinar Nucleus Research Articles

Predicting Sumatriptan Responsiveness Based on Structural Connectivity in Patients Newly Diagnosed With Migraine.

We aimed to determine whether structural brain connectivity is significantly associated with the response to sumatriptan in patients with migraine. We retrospectively enrolled patients with newly diagnosed migraine who underwent brain diffusion-tensor imaging (DTI) at the time of diagnosis, with regular follow-up for at least 6 months after the initial diagnosis. Patients were classified into good- and poor-responder groups according to their response to sumatriptan. We analyzed the structural connectivity using DTI by applying graph theory using DSI Studio software. We enrolled 59 patients (35 good responders and 24 poor responders) and 30 healthy controls. Global structural connectivity differed significantly between patients with migraine and healthy controls, while local structural connectivity differed significantly between good and poor responders. The betweenness centrality was lower in good responders than in poor responders in the left lateral geniculate thalamic nucleus (26.078 vs. 41.371, p=0.039) and right medial mediodorsal magnocellular thalamic nucleus (60.856 vs. 90.378, p=0.021), whereas was higher in good responders in the left lateral pulvinar thalamic nucleus (98.365 vs. 50.347, p=0.003) and right medial pulvinar thalamic nucleus (216.047 vs. 156.651, p=0.036). We found that structural connectivity in patients with migraine differed from that in healthy controls. Moreover, the local structural connectivity varied with the response to sumatriptan, which suggests that structural connectivity is a useful factor for predicting how a patient will respond to sumatriptan.

Increased Blood-Brain Barrier Permeability of the Thalamus Correlated With Symptom Severity and Brain Volume Alterations in Patients With Schizophrenia

BackgroundWhile direct in vivo data from patients is insufficient, cumulative evidence of microvascular dysfunction has shown that the blood-brain barrier (BBB) is disrupted in schizophrenia. In this study, we attempted to test the hypothesis that greater BBB permeability in patients with schizophrenia was associated with clinical characteristics and brain volumetric alterations using dynamic contrast-enhanced magnetic resonance imaging techniques. MethodsStructural magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging data from 29 patients with schizophrenia and 18 age- and sex-matched control subjects were obtained. We calculated the volume transfer constant (Ktrans) value and compared the difference between the 2 groups. The regions with an abnormal Ktrans value were extracted as regions of interest (thalamus), and the correlations with clinical characteristics and gray matter volume were analyzed. ResultsThe results revealed that Ktrans value of the bilateral thalamus was higher in the schizophrenia group as compared to the healthy control group (p < .001). There were significant positive correlations between thalamic mean Ktrans value with disease duration (p < .05) and symptom severity (p < .001). Analysis of the thalamic subregions revealed that BBB disruption was significant in the pulvinar, especially the medial pulvinar nucleus and lateral pulvinar nucleus (p < .001). The correlation between the Ktrans values and the corresponding volumes was negative for the whole brain, the thalamus, and the thalamic subregions. ConclusionsThese results provide the first in vivo evidence of BBB disruption of thalamus in patients with schizophrenia and suggest that BBB dysfunction might contribute to the pathological brain structural alterations in schizophrenia.

Bridging large-scale cortical networks: Integrative and function-specific hubs in the thalamus

SummaryThe thalamus is critical for the brain's integrative hub functions; however, the localization and characterization of the different thalamic hubs remain unclear. Using a voxel-level network measure called functional connectivity overlap ratio (FCOR), we examined the thalamus' association with large-scale resting-state networks (RSNs) to elucidate its connector hub roles. Connections to the core-neurocognitive networks were localized in the anterior and medial parts, such as the anteroventral and mediodorsal nuclei areas. Regions functionally connected to the sensorimotor network were distinctively located around the lateral pulvinar nucleus but to a limited extent. Prominent connector hubs include the anteroventral, ventral lateral, and mediodorsal nuclei with functional connections to multiple RSNs. These findings suggest that the thalamus, with extensive connections to most of the RSNs, is well placed as a critical integrative functional hub and could play an important role for functional integration facilitating brain functions associated with primary processing and higher cognition.

Development of lateral pulvinar resting state functional connectivity and its role in attention

ObjectiveThe lateral pulvinar nucleus (LPN) has a well-established role in visual attention. Oscillatory activity of the LPN is critical for cortico-cortical communication within and among occipital and temporal visual processing regions. However, the functional development of the LPN and its role in attention deficits is not understood. This study examined the development of thalamic functional connectivity and its relation to attention abilities. MethodResting state functional Magnetic Resonance Imaging images from 950 participants (ages 8–21) in the Philadelphia Neurodevelopmental Cohort (PNC) were used to examine age effects. Follow-up General Linear Models were performed to examine brain-behavior effects with Attention Deficit Hyperactivity Disorder (ADHD) symptom ratings and D-prime scores from the Penn Continuous Performance Task, a behavioral measure of selective attention. ResultsLPN functional connectivity with ventral visual stream regions of the occipital and temporal cortices decreased with age, while LPN functional connectivity with the supplementary motor area increased with age.Weaker LPN connectivity in the inferior parietal lobule, supramarginal gyrus, posterior insula, and inferior frontal gyrus was associated with more ADHD symptoms; stronger pulvinar-cerebellar connectivity was also associated with more ADHD symptoms. Better D-prime scores were associated with greater connectivity between the pulvinar and superior parietal gyrus; better D-prime scores were associated with weaker pulvinar connectivity with striatal, middle temporal gyrus, and medial prefrontal cortex regions. ConclusionThese findings implicate the LPN in the development of the ventral visual processing stream between late childhood and early adulthood and suggest that LPN connectivity with higher order attention networks is important for attention abilities.

Intrinsic connectivity networks in posterior cortical atrophy: A role for the pulvinar?

BackgroundPosterior cortical atrophy (PCA) is a clinical variant of Alzheimer's disease (AD) that presents with progressive visuospatial symptoms. While amnestic AD is characterized by disrupted default mode network (DMN) connectivity with corresponding increases in salience network (SN) connectivity, a visuospatial network appears to be disrupted early in PCA. Based on PCA patients' clinical features, we hypothesized that, in addition to early decreased integrity within the visuospatial network, patients with PCA would show increases in SN connectivity despite relative preservation of DMN. As the lateral pulvinar nucleus of the thalamus has direct anatomical connections with striate and extrastriate cortex and DMN, and the medial pulvinar is anatomically interconnected with SN, we further hypothesized that lateral and medial pulvinar nuclei might be implicated in intrinsic connectivity changes in PCA.Methods26 patients with PCA and 64 matched controls were recruited through UCSF Memory and Aging Center research programs. Each completed a standardized neuropsychological battery, structural MRI, and task-free fMRI. Seed-based functional correlations were used to probe networks of interest, including those seeded by the medial and lateral pulvinar thalamic nuclei, across the whole brain, and functional data analyses were adjusted for brain atrophy.ResultsPatients with PCA showed disproportionate deficits in the visuospatial domain; they also showed preserved social sensitivity and endorsed more depressive symptoms than HCs. PCA patients had significant parietooccipital atrophy accompanied by widespread connectivity decreases within the visuospatial network, enhanced connectivity between some structures in SN, and enhanced connectivity between key nodes of the DMN compared to controls. Increased SN connectivity correlated with a measure of social sensitivity, and increased DMN connectivity correlated with short-term memory performance. Medial pulvinar connectivity increases in PCA were topographically similar to SN (anterior insula) connectivity increases, while lateral pulvinar connectivity increases were similar to DMN (posterior cingulate) connectivity increases.ConclusionsPCA is characterized by preserved to heightened connectivity in the SN and DMN despite decreased visuospatial network connectivity. The spatial similarity of medial and lateral pulvinar connectivity changes to those seen in the SN and DMN suggests a role for the pulvinar in intrinsic connectivity network changes in PCA.

INTRINSIC CONNECTIVITY NETWORKS IN POSTERIOR CORTICAL ATROPHY: A ROLE FOR THE PULVINAR?

Author(s): Fredericks, Carolyn A; Brown, Jesse A; Deng, Jersey; Kramer, Abigail; Ossenkoppele, Rik; Rankin, Katherine; Kramer, Joel H; Miller, Bruce L; Rabinovici, Gil D; Seeley, William W | Abstract: BackgroundPosterior cortical atrophy (PCA) is a clinical variant of Alzheimer's disease (AD) that presents with progressive visuospatial symptoms. While amnestic AD is characterized by disrupted default mode network (DMN) connectivity with corresponding increases in salience network (SN) connectivity, a visuospatial network appears to be disrupted early in PCA. Based on PCA patients' clinical features, we hypothesized that, in addition to early decreased integrity within the visuospatial network, patients with PCA would show increases in SN connectivity despite relative preservation of DMN. As the lateral pulvinar nucleus of the thalamus has direct anatomical connections with striate and extrastriate cortex and DMN, and the medial pulvinar is anatomically interconnected with SN, we further hypothesized that lateral and medial pulvinar nuclei might be implicated in intrinsic connectivity changes in PCA.Methods26 patients with PCA and 64 matched controls were recruited through UCSF Memory and Aging Center research programs. Each completed a standardized neuropsychological battery, structural MRI, and task-free fMRI. Seed-based functional correlations were used to probe networks of interest, including those seeded by the medial and lateral pulvinar thalamic nuclei, across the whole brain, and functional data analyses were adjusted for brain atrophy.ResultsPatients with PCA showed disproportionate deficits in the visuospatial domain; they also showed preserved social sensitivity and endorsed more depressive symptoms than HCs. PCA patients had significant parietooccipital atrophy accompanied by widespread connectivity decreases within the visuospatial network, enhanced connectivity between some structures in SN, and enhanced connectivity between key nodes of the DMN compared to controls. Increased SN connectivity correlated with a measure of social sensitivity, and increased DMN connectivity correlated with short-term memory performance. Medial pulvinar connectivity increases in PCA were topographically similar to SN (anterior insula) connectivity increases, while lateral pulvinar connectivity increases were similar to DMN (posterior cingulate) connectivity increases.ConclusionsPCA is characterized by preserved to heightened connectivity in the SN and DMN despite decreased visuospatial network connectivity. The spatial similarity of medial and lateral pulvinar connectivity changes to those seen in the SN and DMN suggests a role for the pulvinar in intrinsic connectivity network changes in PCA.

Gating and control of primary visual cortex by pulvinar

The primary visual cortex (V1) receives its driving input from the eyes via the lateral geniculate nucleus (LGN) of the thalamus. The lateral pulvinar nucleus of the thalamus also projects to V1 but this input is little understood. We manipulated lateral pulvinar neural activity and assessed the effect on supra-granular layers of V1 that project to higher visual cortex. Reversibly inactivating lateral pulvinar prevented supra-granular V1 neurons from responding to visual stimulation. Reversible, focal excitation of lateral pulvinar receptive fields increased 4-fold the visual responses in coincident V1 receptive fields and shifted partially overlapping V1 receptive fields towards the center of excitation. V1 responses to regions surrounding the excited lateral pulvinar receptive fields were suppressed. LGN responses were unaffected by these lateral pulvinar manipulations. Excitation of lateral pulvinar after LGN lesion activated supra-granular layer V1 neurons. Thus, lateral pulvinar is able to powerfully control and gate information outflow from V1.

A morphological anomaly of the dorsal lateral geniculate nucleus in Macaca fascicularis.

In the present report we describe a morphological anomaly of the thalamus. In three macaque monkeys (Macaca fascicularis), we observed up to five finger-like protrusions that emanated from the posterior pole of the dorsal lateral geniculate nucleus (LGN) and extended posteriorly between the lateral pulvinar and reticular nucleus of the thalamus. These anomalous fingers measured up to 1.7 mm in length and contained dense accumulations of neurons and glia. The fingers received a direct retinal input from the contralateral eye indicating that they were part of the LGN rather than of other adjacent thalamic nuclei. In order to determine with which subcompartment(s) of the LGN the fingers were associated (parvocellular, magnocellular, or intercalated layers), we examined the immunochemical properties and size of neurons in the fingers and LGN subcompartments. We concluded that the fingers were not associated with the intercalated layers, since neurons in the fingers did not stain with an antibody to calbindin-D28k, whereas intercalated neurons stained intensely with this antibody. In addition, neurons located in the fingers were significantly smaller than those found in the magnocellular layers but were not significantly different in size from neurons in the parvocellular layers. We therefore consider that the fingers are an anomaly of the parvocellular subcompartment of the LGN. Interestingly, in two of the three cases with anomalous fingers, we also observed subsidiary parvocellular laminae, suggesting that these two anomalies were related. In five additional animals, however, we observed subsidiary parvocellular laminae without anomalous fingers. Thus, if there are common mechanisms underlying the development of both anomalous fingers and subsidiary layers, our data indicate that they do not always result in the concomitant expression of both anomalies.

The spatial distribution of pulvinar neurons that project to two subregions of the inferior parietal lobule in the macaque.

The distribution of pulvinar neurons that project to the lateral intraparietal area (LIP) and area 7a, two subregions of the inferior parietal lobule in monkeys, was determined using small injections of retrogradely transported fluorescent dyes. Both LIP and 7a received the majority of their thalamic input from contiguous but distinct zones within the medial pulvinar nucleus. Thalamocortical cell bodies that projected to LIP were arranged in a dense, horizontally oriented cluster that was sandwiched between two similar clusters of neurons that projected to 7a. There was minimal overlap of the respective clusters. LIP also received an appreciable input from the dorsal half of the lateral pulvinar nucleus, but tracer placements in 7a resulted in only occasional labeled neurons in the lateral pulvinar.

Visual pretectal neurons projecting to the dorsal lateral geniculate nucleus and pulvinar nucleus in the cat

Visual pretectal neurons projecting to the dorsal lateral geniculate nucleus and pulvinar nucleus in the cat

The thalamic relations of the caudal inferior parietal lobule and the lateral prefrontal cortex in monkeys: divergent cortical projections from cell clusters in the medial pulvinar nucleus.

The thalamic relations of the caudal inferior parietal lobule and the dorsolateral prefrontal cortex in monkeys have been investigated with both anterograde and retrograde neuroanatomical tracing techniques. The results of these experiments indicate that the medial pulvinar nucleus (Pul.m.) is the principal thalamic relay to the gyral surface of the caudal inferior parietal lobule (area 7a). Within the Pul.m. there are two or three disklike aggregates of neurons which project to area 7a; these disklike neuronal aggregates are oriented from dorsomedial to ventrolateral and extend over most of the rostrocaudal extent of the nucleus. Within these disks there are rodlike clusters of neurons which are elongated in the rostrocaudal dimension of the thalamus, and which project in a topographically ordered manner to area 7a. Thus, the more rostrally located neurons within the Pul.m. disks project to more rostral parts of area 7a and, conversely, the more caudally located neurons project to the caudal part of this cortical field. Similarly, the medial part of each disk projects to the lateral part of area 7a while the laterally placed neurons project to the medial part of the cortical field. In addition to its input from the Pul.m., area 7a is also reciprocally connected with the magnocellular division of the nucleus ventralis anterior, with the nuclei which abut upon the medullary capsule of the laterodorsal nucleus, and with the suprageniculate nucleus and the nucleus limitans. The cortex on the lateral bank of the intraparietal sulcus (the so-called lateral intraparietal area, LIP) projects principally to the lateral pulvinar nucleus (Pul.l) of the thalamus rather than to Pul.m. Area LIP has been found to project to the pregeniculate nucleus, the zona incerta, the anterior pretectal nucleus, and the superior colliculus. Area 7a projects to none of these structures, but it does project to the posterior pretectal nucleus. The thalamic relations of the neighboring cortical regions, such as the prelunate gyrus and area 7b, are also distinct from those of area 7a. It thus seems that the prelunate gyrus is primarily interconnected with the Pul.l., and area 7b with the oral pulvinar nucleus. Taken together these different subcortical relationships provide further evidence for the view that the caudal inferior parietal lobule is not a homogeneous cortical area, but is composed of a number of subsidiary fields. The projection from the Pul.m. to the lateral prefrontal cortex arises from disklike aggregates of neurons, similar in their orientation to the neuronal disks that project to area 7a.(ABSTRACT TRUNCATED AT 400 WORDS)

The morphology and laminar distribution of cortico-pulvinar neurons in the Rhesus monkey

Using autoradiography and the horseradish peroxidase method, the morphology and laminar distribution of cortico-pulvinar neurons and the reciprocity of connections between pulvinar and cortex were examined in five Rhesus monkeys which had received medial, lateral and inferior pulvinar nucleus injections of both tritiated amino acids and horseradish peroxidase. Cortico-pulvinar neurons were identified in one heterotypical cortical area (area 17) and in many homotypical areas in frontal (areas 45, 46, 11, 12), parietal (5, 7), occipital (18, 19) and temporal (20, 21, 22) lobes. The cortico-pulvinar neurons were pyramidal in shape and ranged in size from small to large. In heterotypical cortex they were found in layers V and VI whereas in area 17 they were found only in layer Vb. Reciprocal connections between pulvinar and cortex were a feature of homotypical but not heterotypical cortex.

Projections from the striate cortex to the diencephalon in the squirrel monkey (Saimiri sciureus). A light microscopic radioautographic study following intracortical injection of H3 leucine.

AbstractTritiated leucine was injected into three different regions of the striate cortex in nine squirrel monkeys and the axoplasmic transport of labelled protein in the neurons was used to identify terminal fields of projection in the thalamus. The regions of injection corresponded to those representing about 3°, 10°, and 30° eccentricity in the contralateral visual field. The periods of post‐injection survival were 9–19 hours, 8 days, and 23 days. The exposure was about three weeks in all cases. In the thalamus terminal fields of projection were identified in the lateral geniculate nucleus, the posterior nucleus of the thalamus, the inferior and lateral pulvinar nucleus, the reticular nucleus of the thalamus and the pregeniculate nucleus. In most of the projections the location of the terminal fields varied systematically with the location of the injection site indicating a retinotopic organization. In eight of the nine experiments all of the thalamic projections were observed. In the cases with postinjection survival times of 8 and 23 days pronounced axonal labelling was seen, and the corticothalamic pathway could be traced from the site of injection to the thalamus. In one experiment in which only the superficial layers of the cortex were labelled by the injection no thalamic projection was found.

Cortical projections of the pulvinar nuclear group of the thalamus in the cat.

Localized stereotaxic lesions wereplaced in the pulvinar nuclear group of the cat thalamus, and the ensuing fiber degeneration was traced to the cerebral cortex by the method of Nauta and Gygax. The medial pulvinar nucleus (the major portion of nucleus lateralis pars posterior of Rioch) projects fibers to the banks, particularly the lateral, and fundus of the middle and posterior portion of the middle suprasylvian sulcus and the adjacent part of the posterior ectosylvian gyrus, and to the caudal bank of the posterior suprasylvian sulcus. The lateral pulvinar nucleus (pulvinar of Rioch) sends fibers to the crown and the medial and lateral sulcal lips of the middle and posterior suprasylvian gyri, the zone of confluence of the posterolateral and posterior suprasylvian gyri, and the medial cortex around the splenial sulcus including its fundus, area 19. The inferior pulvinar nucleus (nucleus posterior of Rioch) projects mainly to the medial bank of the lateral sulcus (area 19) and the medial bank of the middle suprasylvian sulcus (Clare-Bishop area). It also appears to send some fibers to the lateral bank of the lateral sulcus and parts of the convexities of the lateral and suprasylvian gyri. The supra-geniculate nucleus gives off fibers to the anterior sylvian gyrus and the adjoining posterior bank of the anterior ectosylvian sulcus, and probably to the cortex around the anterior half of the middle suprasylvian sulcus.

Cortical Projections of the Pulvinar Nuclear Group of the Thalamus in the Cat; pp. 440–457

Localized stereotaxic lesions were placed in the pulvinar nuclear group of the cat thalamus, and the ensuing fiber degeneration was traced to the cerebral cortex by the method of Nauta and Gygax. The medial pulvinar nucleus (the major portion of nucleus lateralis pars posterior of Rioch) projects fibers to the banks, particularly the lateral, and fundus of the middle and posterior portion of the middle suprasylvian sulcus and the adjacent part of the posterior ectosylvian gyrus, and to the caudal bank of the posterior suprasylvian sulcus. The lateral pulvinar nucleus (pulvinar of Rioch) sends fibers to the crown and the medial and lateral sulcal lips of the middle and posterior suprasylvian gyri, the zone of confluence of the posterolateral and posterior suprasylvian gyri, and the medial cortex around the splenial sulcus including its fundus, area 19. The inferior pulvinar nucleus (nucleus posterior of Rioch) projects mainly to the medial bank of the lateral sulcus (area 19) and the medial bank of the middle suprasylvian sulcus (Clare-Bishop area). It also appears to send some fibers to the lateral bank of the lateral sulcus and parts of the convexities of the lateral and suprasylvian gyri. The supra-geniculate nucleus gives off fibers to the anterior sylvian gyrus and the adjoining posterior bank of the anterior ectosylvian sulcus, and probably to the cortex around the anterior half of the middle suprasylvian sulcus.

Occurrence of Cylindrical Synaptic Vesicles in the Central Nervous System Perfused with Buffered Formalin Solution Prior to OsO&lt;sub&gt;4&lt;/sub&gt;-fixation

In the brain perfused with buffered formalin solution and post-fixed with OsO4 fixative, there can be found a new type of synaptic vesicles which is not observable in materials simply fixed with OsO4 fixatives. These vesicles are of cylindrical form, 240-300A in diameter and 300-1000A in length. They occur either in terminals of the type of boutons terminaux or in neuronal processes forming synapses en passant, and can be found in various regions of the central nervous system examined, including olfactory bulb, cerebral and cerebellar cortex, hippocampal formation, septal region, habenular nuclei, dorsal nucleus of the lateral geniculate body, lateral pulvinar nucleus, preoptic area, hypothalamic suprachiasmatic and ventromedial nuclei and anterior horn of the spinal cord. The terminals containing such vesicles make synaptic junctions both with neuronal perikarya and with dendrites. There, the synaptic cleft is somewhat narrower and the thickening of the synaptic membranes are less marked than at synapses the presynaptic component of which does not contain cylindrical vesicles. Sometimes synaptic junction is formed between a terminal with cylindrical vesicles and that exclusively with ordinary, spherical vesicles. In the majority of these axo-axonal synapses the presynaptic component does not contain cylindrical vesicles but spherical ones solely.The terminals with cylindrical vesicles occur in a considerably constant freguency in a given area of the central nervous system. For example, it was estimated as 18% of all the terminals in the lateral pulvinar nucleus and 25% in the caudate nucleus.A possible explanation on the occurrence of these synaptic vesicles only in the perfused materials was presented and some comments on the perfusion technique were also made.

Synaptic Organization of the Lateral Pulvinar Nucleus in the Cat

Synaptic organization of the cat lateral pulvinar nucleus was studied electron microscopically in the materials perfused with buffered formalin solution and post-fixed with OsO4. The receptive areas of the pulvinar neuron can be classified into 1) small, direct issues of the dendritic trunk, which make the glomerular synapse (MAJOROSSY et al. 1965), 2) pro imal den ritic branches making complex axo-dendritic synapses and 3) distal fine dendritic branches with rather simple synaptic contacts with nerve terminals. On the other hand, three kinds of axon terminals are identified in the neuropile of the pulvinar: a) most frequently occurring, smaller terminals containing spherical vasicles alone, b) larger terminals with cylindrical vesicles and c) the largest mossy endings of rather rare occurrence. The ratio in number of the terminals of each type in about a thousand of terminals sampled at random from this brain region is considerably constant among materials from different control animals. Ablation of the cortical regions which project to the pulvinar induced the changes in this ratio, thus suggesting that the reduced type of terminals might correspond, at least in part, to the endings of the ablated projection fibers. The utility of this phenomenon in determining the type of axon terminals of a given projection system was discussed.