Nuestros profesionales publican en revistas científicas de alto impacto con el objetivo de ofrecer a nuestros pacientes los últimos tratamientos. Clínica Universidad de Navarra

http://www.hindawi.com/journals/ert/2012/769825/fig6/ The medial view of the anterior segment of the medial temporal region (MTR). (This illustration correlates with Figures 6(b) and 6 ©). The anterior choroidal artery (AChA) gives off an anterior uncal artery that irrigates the semilunar gyrus and an uncohippocampal artery that irrigates the uncinate gyrus and band of Giacomini and penetrates the uncal sulcus to vascularize the extraventricular hippocampal head. The internal carotid artery (ICA) gives off an anterior uncal artery that supplies the semilunar gyrus. This branch usually is present when the anterior uncal artery of the AChA is absent. An anterior uncal artery also arises from the M1 segment of the middle cerebral artery (MCA) and supplies the ambient gyrus. An uncoparahippocampal artery arises from the temporopolar artery and irrigates both the ambient gyrus and the anterior parahippocampal area. Branches from the P2a segment of the PCA irrigate the anterior parahippocampal region ...

Back when I was young, sleep learning was a popular idea. The idea was that a tape would play while you were asleep, and learning would seep into your brain effortlessly. It was particularly advocated for language learning. Subsequent research, unfortunately, rejected the idea, and gradually it has faded (although not completely). Now a new study may presage a come-back.. In the study, 16 young adults (mean age 21) learned how to play two artificially-generated tunes by pressing four keys in time with repeating 12-item sequences of moving circles - the idea being to mimic the sort of sensorimotor integration that occurs when musicians learn to play music. They then took a 90-minute nap. During slow-wave sleep, one of the tunes was repeatedly played to them (20 times over four minutes). After the nap, participants were tested on their ability to play the tunes.. A separate group of 16 students experienced the same events, but without the playing of the tune during sleep. A third group stayed ...

The parahippocampal region (PHR) is an interface region between the hippocampus and the neocortex located in the medial temporal lobe (MTL) (Squire and Zola-Morgan, 1991; Lavenex and Amaral, 2000; Squire et al., 2004). The PHR has been implicated in many functions, including long-term memory (for reviews, see Squire et al., 2004; Eichenbaum et al., 2007), working memory (Jeneson and Squire, 2012; Libby et al., 2014), and perception (ONeil et al., 2009; Barense et al., 2010). Given these important and complex functions of the PHR, identifying its anatomical organization is necessary for expanding our understanding and studying the functional relevance of its subregions.. Based on the traditionally accepted parcellation scheme for the PHR [i.e., entorhinal cortex (ERC), perirhinal cortex (PRC), and parahippocampal cortex (PHC)] (Squire and Zola-Morgan, 1991; Insausti et al., 1998; Burwell, 2000; Ding and Van Hoesen, 2010; Kivisaari et al., 2013), a considerable body of research has focused on ...

The uncus is the innermost part of the anterior parahippocampal gyrus, part of mesial temporal lobe. Gross anatomy The uncus is the most anterior portion of the medial parahippocampal gyrus. It belongs to the limbic system. Housing the primary...

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The first step in landmark-based piloting is landmark recognition-that is, identification of landmarks when one is directly in their presence. In theory, the brain could have used a general-purpose object recognition system to solve this problem. However, it appears to rely instead on a specialized mechanism for landmark recognition, analogous in many ways to the specialized mechanism that is believed to support face recognition.. The primary neural locus of this mechanism is the parahippocampal place area (PPA)-a region in the collateral sulcus near the parahippocampal/lingual boundary that exhibits a strong functional magnetic resonance imaging (fMRI) response when subjects view environmental stimuli, such as buildings, streets, rooms and landscapes [3,4]. By contrast, the PPA only responds weakly when subjects view common everyday objects, such as vehicles, tools and appliances, and it does not respond at all when they view faces. Notably, the PPA exhibits this strong preference for ...

Fig: Distinct topography of place-memory and scene-perception activity in posterior cerebral cortex.. In all participants, three place-memory areas were observed, each located significantly anterior to one region of the scene-perception network. One example participant in Experiment 1 is shown (See Supplementary and Supplementary Video for thresholded and unthresholded activation maps for all participants (n = 14)). The participants scene perception ROIs are outlined in white, and place-memory activity is shown in warm colors. The scene-perception network (parahippocampal place area [PPA], occipital place area [OPA], and medial place area [MPA]) was localized by comparing the BOLD response when participants viewed images of scenes versus with faces (outlined in white, thresholded at vertex-wise p , 0.001). Place-memory areas on each surface were localized in separate fMRI runs by comparing the BOLD response when participants recalled personally familiar places versus people (warm colors, ...

Understanding the subtlety of this usage requires second-order interpretation of the speakers or writers intentions; different parts of the brain must work together to understand sarcasm. This sophisticated understanding can be lacking in some people with certain forms of brain damage, dementia and autism (although not always),[10] and this perception has been located by MRI in the right parahippocampal gyrus.[11][12] Research has shown that people with damage in the prefrontal cortex have difficulty understanding non-verbal aspects of language like tone, Richard Delmonico, a neuropsychologist at the University of California, Davis, told an interviewer.[13] Such research could help doctors distinguish between different types of neurodegenerative diseases, such as frontotemporal dementia and Alzheimers disease, according to David Salmon, a neuroscientist at the University of California, San Diego.[13]. In William Brants Critique of Sarcastic Reason,[14] sarcasm is hypothesized to develop as a ...

The tentorium divides the intracranial cavity into an infratentorial compartment, which contains the brainstem and the cerebellum, and a supratentorial compartment, with the 2 cerebral hemispheres divided by the falx and the diencephalic structures. The subdivision of each hemisphere into lobes is based originally on the bones of the skull and has little to do with the functional aspects of each region. The insular lobe, which includes only the insular surface and subcortical white matter, lies deep and is enclosed by the frontoparietotemporal opercula. Although not related to any bone of the skull, the insular lobe has long been recognized as a distinct region since its original description by Reil in 1809.33,39 The concept of a limbic lobe, introduced by Paul Broca in 1877 as including exclusively the cingulate and parahippocampal gyri2 and later modified by others to include medial portions of the frontal, parietal and temporal lobes, the septal region, the perirhinal cortex, the entorhinal ...

immune Uncategorized 671225-39-1 supplier, Rabbit Polyclonal to MAP3K8 (phospho-Ser400) Earlier work has proven a distinction between maintenance of two types of spatial information in operating memory (WM): spatial locations and spatial relations. vs. relationships. Maintaining a spot, in comparison to a connection, was connected with higher activity in normal spatial WM areas like posterior parietal cortex and prefrontal areas. Whereas keeping a connection, compared to a spot, was connected with higher activity in the parahippocampal gyrus and precuneus/retrosplenial cortex. Further, in Test 2 we manipulated WM fill and included tests where participants got to keep up three spatial places or relationships. Under this high fill condition, the areas delicate to places vs. relationships were unique of under low fill somewhat. We also determined areas which were delicate to fill for area or connection maintenance particularly, aswell as overlapping areas delicate to load even more generally. These ...

Ripples (100-250 Hz) and fast ripples (FR, 250-500 Hz) have been previously identified with microelectrodes in human hippocampus (Bragin et al., 1999, 2002) and were more prominent during non-REM sleep (Staba et al., 2004). FR occurrences are significantly associated with seizure-generating areas (Bragin et al., 2002; Engel et al., 2009). For investigating differences between these fast oscillations and gamma, we have systematically detected during SWS, ipsilateral to side of seizure onset, all high-frequency oscillations between 40 and 600 Hz in the hippocampus and adjacent parahippocampal gyri of five subjects. In the hippocampus, analysis of frequencies at maximum power showed a multimodal distribution in the high-frequency range with three main peaks around 50, 190, and 360 Hz (occurrence times for a single subject in Fig. 5A, and histogram over all subjects in Fig. 5B). On the basis of these data, and results from our previous studies, subsequent analyses of gamma, ripples, and FR were ...

For the most part, the old icons are exact copies of the 2007 old icons download from Mythic with some (very-few!) item-based icon exceptions that have a similar/identical look but larger image under the newer icon styling (such as jewels, necklaces, and potion icons ...

BackgroundEarly and late mild cognitive impairment (MCI) patients have been reported to have a distinctive prognosis of converting to Alzheimers disease.ObjectiveTo evaluate the difference in gray matter volume and assess the association between cognitive function evaluated by comprehensive cognitive function test, and cortical thickness across healthy controls (HCs) (n = 37), early (n = 30), and late MCI patients (n = 35).MethodsDifferences in gray matter volume were evaluated by whole brain voxel-based morphometry across the groups. Multiple regression analysis was used to analyze group by memory performance interactions for the normalized gray matter volume.ResultsThe early MCI group showed reduced gray matter volume in the right middle temporal gyrus in comparison to the HC group. The late MCI group displayed atrophy in the left parahippocampal gyrus in comparison to the HC group. Late MCI patients exhibited a decreased gray matter volume in the left fusiform gyrus in comparison to patients in the

Broca named the limbic lobe in 1878, identifying it with the cingulate and parahippocampal gyri, and associating it with the sense of smell - Treviranus having earlier noted that, between species, the size of the parahippocampal gyrus varies with the size of the olfactory nerve.[2] In 1937 Papez theorized that a neural circuit (the Papez circuit) including the hippocampal formation and the cingulate gyrus constitutes the neural substrate of emotional behavior,[3] and Klüver and Bucy reported that, in monkeys, resection involving the hippocampal formation and the amygdaloid complex has a profound effect on emotional responses.[4][5] As a consequence of these publications, the idea that the entire limbic lobe is dedicated to olfaction receded, and a direct connection between emotion and the limbic lobe was established.[6]. ...

Using high-resolution structural images and VBM, we investigated changes in global and regional GM volume in SLE patients with and without neuropsychiatric manifestations and in healthy controls. There were no statistically significant differences in global GMV or WMV between the 3 groups. Regional GM atrophy was found in SLE and NPSLE, most prominently in the thalamus bilaterally and also in the precentral gyrus, the parietal lobe/precuneus, and the occipital lobe. Further, we found an increase in regional GMV in the posterior part of the parahippocampal gyrus on the left side in SLE patients and bilaterally in NPSLE patients (at the threshold determined a priori). Using the statistical approach/threshold described above, we found no significant differences between the NPSLE and SLE patients, although the changes in the thalamus and parahippocampal gyrus were more pronounced in NPSLE patients.. With respect to the patients with NPSLE, our data are in agreement with other studies using automated ...

The neuromodulatory effect of manipulating monoaminergic receptor function was assessed by combining a psychological and a pharmacological activation during repeated positron emission tomographic (PET) scans. The effects of buspirone (a 5-HT1A receptor partial agonist) on changes in regional cerebral blood flow (rCBF) associated with free word recall were examined. A factorial design was used to demonstrate a significant interaction (changes in rCBF brought about by psychological activation which depend on drug administration) in the left parahippocampal region. This interaction was an attenuation of increases in local neuronal activity (rCBF) related to memory function. Buspirone-induced decreases in rCBF, independent of the memory effect, were seen in the left prefrontal and parietal cortices. We suggest that combined psychological and pharmacological activation is a way of measuring direct (main) drug effects and modulatory effects on neurotransmission associated with cognitive functions (interaction

Autor: Qin, Shaozheng et al.; Genre: Zeitschriftenartikel; Im Druck veröffentlicht: 2009; Open Access; Keywords: Episodic memory|br/|Hippocampus|br/|Parahippocampal cortex|br/|Perirhinal cortex|br/|Prefrontal cortex; Titel: Dissecting medial temporal lobe contributions to item and associative|br/|memory formation

Origin:. The uncal artery is the cerebral part of the internal carotid artery or occasionally from the sphenoidal part (M1 segment) of the middle cerebral artery. It measured 0.7 mm in diameter and gave off small branches to the uncus, as well as a large parahippocampal artery, the accessory anterior temporal artery, and the anterior hippocampal artery. This uncal artery supplied, in addition to the uncus, most of the ventromedial surface of the parahippocampal gyrus, part of its dorsal surface, the rostromedial portion of the lateral occipitotemporal gyrus, and the rostral part of the hippocampal formation. ...

Old and recent memories are retrieved differently. For the very first time we were able to show that the retrieval of old and recent memories are supported by distinct brain networks, Prof. Dr. Magdalena Sauvage reports. The CA3 region, believed to be the place of memory storage in the hippocampus, no longer plays a role when we remember very old memories. Rather, the involvement of the CA1 region persists and the cortical areas adjacent to the hippocampus become involved. The reason for the differential involvement of the hippocampal subregions could lie in the mechanisms supported by CA3, explains Prof. Sauvage: In CA3, memories can be retrieved on the basis of single features of an original memory, which are used as cues. Since the memory for single features degrades over time, we speculate that they might ultimately be of no more use as cues, hence retrieving memory would then essentially rely on CA1 and other processes taking place in the parahippocampal region of the brain. ...

The functional topography of the motor cortex represents natural movement patterns (Aflalo and Graziano, 2011). Here we asked if such movement patterns are already represented at the beginning of the perception-action cycle in that visual areas represent the motor programs that are typically used in looking at specific visual stimuli. Specifically, we investigated whether the fusiform face area (FFA) and the parahippocampal place area (PPA) contain a representation of gaze patterns that are used when looking at faces or houses. For this purpose, we instructed observers to follow a dot presented on a uniform background. In Experiment 1 and 2, the dots movement represented 3000ms of the gaze path acquired from an independent observer while looking at face or house pictures. Results from Experiment 1 showed that face- and house-associated gaze patterns could be discriminated by multivariate pattern analysis in FFA and PPA. This discrimination was still observed when gaze dispersion differences ...

Recent research has demonstrated (a) that the perirhinal cortex (PRC) encodes complex object-level configurations of features, and (b) these representations participate in discriminating familiar versus novel configurations. The ventral visual stream is able to identify familiar object parts as such even in the face of PRC damage, although it cannot identify their configuration as correct or incorrect Barense et al. (2011). Here, we use fMRI to investigate whether extrastriate cortex in the intact brain a). is sensitive to the configuration of parts of familiar objects and b). covaries with activation in the PRC. Participants viewed peripherally presented silhouettes (nearest edge 4°) that portrayed familiar or novel objects. There were 3 types of silhouettes: familiar configurations (objects that exist in the real world); part-rearranged novel configurations (rearranged parts of the familiar configurations); and novel configurations created by (inverted part-rearranged novel configurations) ...

Tour 1: Next/Previous/Start: The following section summarizes the brain damage in this case, and links each structure mentioned to its entry in the Atlas of the normal brain. Move through the dataset (use the buttons at left) to view each of the structures mentioned. Abnormally high signal extends from the right temporal tip medially to involve the hippocampus, amygdala, and the parahippocampal gyrus, superiorly to involve orbital frontal gyri, the straight gyrus, and the cingulate gyrus; and posteriorly and superiorly to involve the insula, the anterior bank of the superior temporal gyrus, and the posterior hippocampus as it blends into the column of the fornix. Medially, the lesion displays evidence of tracking along an anatomically restricted course, as it borders the posterior genu of the internal capsule. The greatest superior extent of the lesion involves the posterior portion of the medial nucleus of the thalamus, a structure known to have anatomic connections with amygdala and other ...

The hippocampus consists of the complex interfolded layers of the dentate gyrus (1) and cornu ammonis (2). Their three layered cortex is continuous below with the subiculum (3) which has four, five then six layers as it merges with the parahippocampal gyrus (4 ...

Memory is a highly complex cognitive function that involves interactions between numerous brain structures, proteins and signalling molecules. Indeed, experience-dependent changes in the strength of synaptic connections between neurons are thought to underlie information storage in the brain. Thus, understanding the highly elastic nature - or the plasticity - of synapses is critical to uncovering how the brain converts our individual experiences into lasting memories. To this end, modulatory neurotransmitter systems play a central role in shaping synaptic processes involved in the encoding and retention of information within neural circuits. A fundamental problem remains, though, in understanding how extrinsic factors recruit, mimic or even hijack these endogenous regulatory signals to affect the development of brain systems critical to cognitive and mnemonic function. The primary focus of my research is in determining how the hippocampus and parahippocampal cortices integrate signals from ...

By employing high-field fMRI to measure connectivity with the hippocampus and adjacent parahippocampal structures within the medial temporal lobe, it is shown that the entorhinal cortex can be divided into anterior-lateral and posterior-medial subregions.

Linear logistic models with relaxed assumptions (LLRA) are a flexible tool for item-based measurement of change or multidimensional Rasch models. Their key features are to allow for multidimensional...

It has been proposed that synaptic density or synaptic innervation may be altered in schizophrenia as a correlate of the neurodevelopmental pathology of the disease. Synaptophysin is a synaptic vesicle protein whose distribution and abundance provides a synaptic marker which can be reliably measured in post mortem brain. We have used in situ hybridization histochemistry and immunoreactivity to assess the expression of synaptophysin messenger RNA and protein respectively in medial temporal lobe from seven schizophrenics and 13 controls. In the schizophrenic cases, synaptophysin messenger RNA was reduced bilaterally in CA4, CA3, subiculum and parahippocampal gyrus, with a similar trend in dentate gyrus but no change in CA1. It was also decreased in terms of grains per pyramidal neuron in the affected subfields. In parahippocampal gyrus, the loss of synaptophysin messenger RNA per neuron in schizophrenia was greater in deep than superficial laminae. A parallel study in rats showed no effect of haloperidol

Children who have a parent with bipolar disorder are at risk for bipolar illness, but it may first present as depression. Treating these children with antidepressants has the risk of bringing on manic episodes. Researchers are looking for treatment options for youth at risk for bipolar disorder.. Robert McNamara and colleagues found that 12 weeks of omega-3 fatty acids (2,100 mg/day) significantly improved response rates in medication-free youth ages 9-20 years compared to placebo (64% versus 36%). Omega-3 fatty acids but not placebo also reduced the activation of limbic structures in the brain (the left parahippocampal gyrus) in response to emotional stimuli.. Editors Note: These data add to the literature on the positive effects of 1-2 grams of omega-3 fatty acids in depression. Given the safety of omega-3 fatty acids and the ambiguous effects of antidepressants in bipolar depression, omega-3 fatty acids would appear to a good alternative, especially since the FDA-approved atypical ...

Introduction: Although, diet has a substantial influence on the aging brain, the relationship between dietary nutrients and aspects of brain health remains unclear. This study examines the neural mechanisms that mediate the relationship between a carotenoid important for brain health across the lifespan, lutein, and crystallized intelligence in cognitively intact older adults. We hypothesized that higher serum levels of lutein are associated with better performance on a task of crystallized intelligence, and that this relationship is mediated by gray matter structure of regions within the temporal cortex. This investigation aims to contribute to a growing line of evidence, which suggests that particular nutrients may slow or prevent aspects of cognitive decline by targeting specific features of brain aging.Methods: We examined 76 cognitively intact adults between the ages of 65 and 75 to investigate the relationship between serum lutein, tests of crystallized intelligence (measured by the Wechsler

In contrast, right midfrontal gyrus connectivity did not differentiate between responders and nonresponders to active medication (duloxetine).. Connectivity with the right parahippocampal gyrus, however, predicted active drug responses after accounting for the placebo response.. By modeling the expected placebo response in subjects receiving active drug treatment, we uncover a placebo-corrected drug response predictive brain signal and show that in some subjects the active drug tends to enhance predicted placebo response, while in others it interferes with it, the researchers write.. Together, these results provide some evidence for clinical placebo being predetermined by brain biology and show that brain imaging may also identify a placebo-corrected prediction of response to active treatment, they add.. Dr. Karin Jensen from Karolinska Institute in Stockholm, Sweden, told Reuters Health by email, It is fascinating to see studies with more and more detailed knowledge about the neural basis ...

EN] We applied the model of temporary total cerebral ischemia in adult monkeys (macaques) by means of reversible interruption of cerebral blood flow. De novo generated cells in ischemic or control subjects were labeled with bromodeoxyuridine (BrdU), an indicator of DNA synthesis. Subsequently, we investigated the distribution and phenotype of cells stained for BrdU in several regions of the cerebrum, at various intervals after ischemia. Ischemia lead to a significant increase in the quantities of de novo generated cells in the hippocampus, the subventricular zone, neocortex and striatum, but with no similar effect on the parahippocampal region. In the olfactory bulb, ischemia did not result in a change in the level of proliferation in the first two post ischemic weeks, but an increase was observed at longer intervals. The majority of new cells outside the germinal centers in the hippocampus and subventricular zone were with glial phenotype, while neurons comprised no more than 1 percent of these ...

Our research on human memory included five tentative categories, i.e. working memory, fact (or semantic memory) memory, episodic memory, motor memory, and prospective memory. We found working memory recruits different networks for different contents such as verbal, visual, and olfactory materials. Also networks for processing and holding materials were found to be different. For processing, strong involvement of the prefrontal lobe was demonstrated. We also found the gradual decline of the capacity of working memory in older population. We found the importance of the right fusiform gyrus in memory of human faces. On the other hand recalling of the name of acquaintances and famous people activated the left temporal pole as well as parieto-occipital area. For the memory of landscapes and streets we found the activation in the medial temporal lobe and parahippocampal gyrus. For episodic memory, we tried to separate neurological substrates for encoding, storing and decoding. Manipulation of the ...

Neurons in the human medial temporal lobe (MTL) that are selective for the identity of specific people are classically thought to encode identity invariant to

TY - JOUR. T1 - Characterization of auditory synaptic inputs to gerbil perirhinal cortex. AU - Kotak, Vibhakar C.. AU - Mowery, Todd M.. AU - Sanes, Dan. PY - 2015/8/14. Y1 - 2015/8/14. N2 - The representation of acoustic cues involves regions downstream from the auditory cortex (ACx). One such area, the perirhinal cortex (PRh), processes sensory signals containing mnemonic information. Therefore, our goal was to assess whether PRh receives auditory inputs from the auditory thalamus (MG) and ACx in an auditory thalamocortical brain slice preparation and characterize these afferent-driven synaptic properties. When the MG or ACx was electrically stimulated, synaptic responses were recorded from the PRh neurons. Blockade of type A gamma-aminobutyric acid (GABA-A) receptors dramatically increased the amplitude of evoked excitatory potentials. Stimulation of the MG or ACx also evoked calcium transients in most PRh neurons. Separately, when fluoro ruby was injected in ACx in vivo, anterogradely ...

Toxin carry out comforts have seen an improvement on pretty much all years just for Cannabidiol (CBD) conditions ever since 2014. When compared with placebo, CBD a lot lessened subjective anxiousness and decreased ethyl cysteinate dimer (ECD) consumption inside kick the habit of parahippocampal gyrus, hippocampus, and also inferior secular gyrus when far better ECD consumption from the precise later(a) cingulate gyrus, so suggesting the antianxiety results for CBD through SAD conceivably involving it is routine inside limbic plus paralimbic intellect locations 38 (Table 2 ). SAD is only cbd oil with regards to the typical plus impairing nervousness challenges still is without a doubt horribly cured with the obtainable medications, along with simply 30% with subject matter accomplishing real remission of sin 60 Due to this, i found check into to get fresh new medicine valuable to protect against diseased anxiousness. Whenever own recognized across 100 plenty of cannabinoids while in the cannabis ...

Poisonous substance control companies have observed a growth throughout just about all quite a while pertaining to Cannabidiol (CBD) circumstances since 2014. Matched against placebo, CBD appreciably lowered subjective nervousness and also minimized ethyl cysteinate dimer (ECD) subscriber base around the leave parahippocampal gyrus, hippocampus, as well as unfavorable secular gyrus though improved ECD uptake in the appropriate posterior cingulate gyrus, consequently indicating a powerful antianxiety consequence about CBD during SAD perhaps connected to the activity in limbic and even paralimbic intellect places 38 (Table 2 ). SAD is exactly with regards to the standard together with impairing anxiousness problems still will be improperly cured because of the obtainable prescriptions, with purely 30% with themes reaching precise remitment 60 Because of this, amazing research for nourishing pills highly effective against pathologic anxiousness. Each and every currently have known finished 100 a ...

The present study extends the observations reported in recent years on the functional interactions within subregions of the PHR. More specifically the experiments focused on the bidirectional propagation of the neural activity from the EC to the adjacent cortices located laterally to the rhinal sulcus namely, PRC, PostRC, and RSpC. The data demonstrated for the first time that despite the presence of anatomical connections between PRC/PostRC/RSpC and the EC, stimulation paradigms that induced synaptic plasticity in PRC/PostRC/RSpC are not sufficient to foster the propagation of the neural activity, originated either in neocortex or in the PRC/PostRC/RSpC itself, to the EC; muscarinic modulation, although critical for the expression of oscillatory processes of the parahippocampal neural network and for specific learning and memory, is not relevant to enhance information flow from PRC to EC and vice versa; the pharmacological inactivation of the GABAergic system in the PRC area 36 facilitates the ...

Three regions of the macaque inferior parietal lobule and adjacent lateral intraparietal sulcus (IPS) are distinguished by the relative strengths of their connections with the superior colliculus, parahippocampal gyrus, and ventral premotor cortex. It was hypothesized that connectivity information could therefore be used to identify similar areas in the human parietal cortex using diffusion-weighted imaging and probabilistic tractography. Unusually, the subcortical routes of the 3 projections have been reported in the macaque, so it was possible to compare not only the terminations of connections but also their course. The medial IPS had the highest probability of connection with the superior colliculus. The projection pathway resembled that connecting parietal cortex and superior colliculus in the macaque. The posterior angular gyrus and the adjacent superior occipital gyrus had a high probability of connection with the parahippocampal gyrus. The projection pathway resembled the macaque inferior

Direct electrical stimulation of the brain has emerged as a powerful treatment for multiple neurological diseases, and as a potential technique to enhance human cognition. Despite its application in a range of brain disorders, it remains unclear how stimulation of discrete brain areas affects memory performance and the underlying electrophysiological activities. Here, we investigated the effect of direct electrical stimulation in four brain regions known to support declarative memory: hippocampus (HP), parahippocampal region (PH) neocortex, prefrontal cortex (PF), and lateral temporal cortex (TC). Intracranial EEG recordings with stimulation were collected from 22 patients during performance of verbal memory tasks. We found that high γ (62-118 Hz) activity induced by word presentation was modulated by electrical stimulation. This modulatory effect was greatest for trials with poor memory encoding. The high γ modulation correlated with the behavioral effect of stimulation in a given brain region: it

TY - JOUR. T1 - Selectivity of pyramidal cells and interneurons in the human medial temporal lobe. AU - Ison, Matias J.. AU - Mormann, Florian. AU - Cerf, Moran. AU - Koch, Christof. AU - Fried, Itzhak. AU - Quiroga, Rodrigo Quian. PY - 2011/10. Y1 - 2011/10. N2 - Neurons in the medial temporal lobe (MTL) respond selectively to pictures of specific individuals, objects, and places. However, the underlying mechanisms leading to such degree of stimulus selectivity are largely unknown. A necessary step to move forward in this direction involves the identification and characterization of the different neuron types present in MTL circuitry. We show that putative principal cells recorded in vivo from the human MTL are more selective than putative interneurons. Furthermore, we report that putative hippocampal pyramidal cells exhibit the highest degree of selectivity within the MTL, reflecting the hierarchical processing of visual information. We interpret these differences in selectivity as a plausible ...

It appears that the brain, that sensitive organ replete with steroid receptors, reacts to its hormonal milieu with startling structural modifications. ....women using hormonal contraceptives showed larger gray matter volumes in the prefrontal cortex, pre- and postcentral gyri, the parahippocampal and fusiform gyri and temporal regions, when compared to naturally cycling women. The brain works like a neural beehive; the proper coordinated functioning of groups of tasked neurons are important to successfully accomplish a variety of mental tasks -- even the sensory processing and motor coordination needed for something as simple as picking up a hot cup of coffee without scalding oneself. Again, we do not know whether this increased gray matter translates into better or worse performance, but there likely is little good about treating a womans brain like a spongy accordion ...

To aim at the problem of blind estimation of low-SNR DS/SS signals spreading sequence, an approach is proposed to estimate the spreading sequence from DS/S

The perception of self and others is a key aspect of social cognition. In order to investigate the neurobiological basis of this distinction we reviewed two classes of task that study self-awareness and awareness of others (theory of mind, ToM). A reliable task to measure self-awareness is the recognition of ones own face in contrast to the recognition of others faces. False-belief tasks are widely used to identify neural correlates of ToM as a measure of awareness of others. We performed an activation likelihood estimation meta-analysis, using the fMRI literature on self-face recognition and false-belief tasks. The brain areas involved in performing false-belief tasks were the medial prefrontal cortex (MPFC), bilateral temporo-parietal junction, precuneus, and the bilateral middle temporal gyrus. Distinct self-face recognition regions were the right superior temporal gyrus, the right parahippocampal gyrus, the right inferior frontal gyrus/ant erior cingulate cortex, and the left inferior parietal

The distribution of beta-amyloid protein (beta A4) was examined in the medial temporal lobes from cases of Alzheimers disease (AD) (n = 13), senile dementia of Lewy body type (SDLT) (n = 12) and age matched controls (n = 9). Using a previously described image analysis technique the extent of beta A4 pathology was determined in ten distinct anatomical sites within the medial temporal lobe. AD and SDLT cases contained very similar amounts of beta A4 in the areas sampled and both contained significantly more beta A4 than the age matched controls, particularly in the dentate and parahippocampal gyri. The similarity of the beta A4 load in the two conditions is in contrast to reported differences in the number of neurofibrillary tangles which can be observed. It is suggested that AD and SDLT represent a spectrum of pathology which centres around the aberrant processing of the beta A4 precursor protein.. ...

SummaryThe origin, course, and termination of parieto-temporal connections in the rhesus monkey were studied by autoradiographic techniques. The caudal third of the inferior parietal lobule (including the adjacent lower bank of the intraparietal sulcus) is the chief source of these projections. It projects to three separate architectonic areas in the superior temporal sulcus and to three different areas on the ventral surface of the temporal lobe: the parahippocampal gyrus, presubiculum, and perirhinal cortex. The mid-inferior parietal lobule and medial surface of the parietal lobe, by contrast, project only to the caudal upper bank of the superior temporal sulcus. The rostral inferior parietal lobule and the superior parietal lobule, as well as the postcentral gyrus and rostral parietal operculum, do not project to the temporal lobe. Fibers travel from the posterior parietal region to temporal cortex by way of several different routes. One fiber bundle courses in the superior temporal gyrus and

While it is commonly accepted that structures in the medial temporal lobe play a critical role in memory, current theories disagree on three fundamental issues: (a) the extent to which different regions within the medial temporal lobe can be functionally dissociated; (b) whether structures within the medial temporal lobe are specialised for memory processing or play an additional role in perception; and (c) whether there is support for functional homology across species. To address these controversial questions, this Special Issue brings together researchers working on memory and perception in the medial temporal lobe and asks whether there is evidence for similar functional dissociations across species. The papers reported here include lesion and early gene imaging in rats, electrophysiological and lesion studies in nonhuman primates, lesion and functional neuroimaging in human participants, as well as touching on computational modelling approaches. Pulling together these methodological diverse

Many current models of working memory (WM) emphasize a close relationship between WM and attention. Recently it was demonstrated that attention can be dynamically and voluntarily oriented to items held in WM, and it was suggested that directed attention can modulate the maintenance of specific WM representations. Here we used event-related functional magnetic resonance imaging to test the effects of orienting attention to a category of stimuli when participants maintained a variable number of faces and scenes in WM. Retro-cues that indicated the relevant stimulus type for the subsequent WM test modulated maintenance-related activity in extrastriate areas preferentially responsive to face or scene stimuli - fusiform and parahippocampal gyri respectively - in a categorical way. After the retro-cue, the activity level in these areas was larger for the cued category in a load-independent way, suggesting the modulation may also reflect anticipation of the probe stimulus. Activity in associative parietal and

A pilot study involving 17 older adults with mild cognitive impairment and 18 controls (aged 60-88; average age 78) has found that a 12-week exercise program significantly improved performance on a semantic memory task, and also significantly improved brain efficiency, for both groups.. The program involved treadmill walking at a moderate intensity. The semantic memory tasks involved correctly recognizing names of celebrities well known to adults born in the 1930s and 40s (difficulty in remembering familiar names is one of the first tasks affected in Alzheimers), and recalling words presented in a list. Brain efficiency was demonstrated by a decrease in the activation intensity in the 11 brain regions involved in the memory task. The brain regions with improved efficiency corresponded to those involved in Alzheimers disease, including the precuneus region, the temporal lobe, and the parahippocampal gyrus.. Participants also improved their cardiovascular fitness, by about ...

It is debated whether subregions within the medial temporal lobe (MTL), in particular the hippocampus (HC) and perirhinal cortex (PrC), play domain-sensitive roles in learning. In the present study, two patients with differing degrees of MTL damage were first exposed to pairs of highly similar scenes, faces, and dot patterns and then asked to make repeated same/different decisions to preexposed and nonexposed (novel) pairs from the three categories (Experiment 1). We measured whether patients would show a benefit of prior exposure (preexposed , nonexposed) and whether repetition of nonexposed (and preexposed) pairs at test would benefit discrimination accuracy. Although selective HC damage impaired learning of scenes, but not faces and dot patterns, broader MTL damage involving the HC and PrC compromised discrimination learning of scenes and faces but left dot pattern learning unaffected. In Experiment 2, a similar task was run in healthy young participants in the MRI scanner. Functional ...

ಕರ್ನಾಟಕ ರಾಜ್ಯದಲ್ಲಿ ಸದ್ಯ ನಡಯುತ್ತಿರುವ ಆಯುಷ್ ವೈದ್ಯರುಗಳ ಮುಷ್ಕರ, NRHM ಅಡಿಯಲ್ಲಿ ಹಾಗೂ PHC ಗಳಲ್ಲಿ MBBS ಎದುರು ಹುದ್ದೆಯಲ್ಲಿ ಗುತ್ತಿಗೆ ಆಧಾರದಲ್ಲಿ ಕೆಲಸ ಮಾಡುತ್ತಿರುವ BAMS ಪದವಿ ಹೊಂದಿರುವ ವೈದ್ಯರುಗಳಿಗೆ ಮಾತ್ರ ಸಂಬಂಧ ಹೊಂದಿರುತ್ತದೆ. ...