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The plant homeodomain zinc-finger protein, PHF6, is a transcriptional regulator, and PHF6 germline mutations cause the X-linked intellectual disability (XLID) Börjeson-Forssman-Lehmann syndrome (BFLS). The mechanisms by which PHF6 regulates transcription and how its mutations cause BFLS remain poorly characterized. Here, we show genome-wide binding of PHF6 in the developing cortex in the vicinity of genes involved in central nervous system development and neurogenesis. Characterization of BFLS mice harbouring PHF6 patient mutations reveals an increase in embryonic neural stem cell (eNSC) self-renewal and a reduction of neural progenitors. We identify a panel of Ephrin receptors (EphRs) as direct transcriptional targets of PHF6. Mechanistically, we show that PHF6 regulation of EphR is impaired in BFLS mice and in conditional Phf6 knock-out mice. Knockdown of EphR-A phenocopies the PHF6 loss-of-function defects in altering eNSCs, and its forced expression rescues defects of BFLS mice-derived eNSCs. Our data indicate that PHF6 directly promotes Ephrin receptor expression to control eNSC behaviour in the developing brain, and that this pathway is impaired in BFLS. Synopsis: This study reveals genome wide binding of PHF6 in the developing cortex and shows that it alters neural stem cells via regulation of Ephrin receptors. PHF6/EphR pathway is impaired in the rare X-linked intellectual disability, BFLS. PHF6 regulates neural stem cell (NSC) fate in the developing brain. PHF6 binds gene regulatory elements of Ephrin receptors (EphR) to upregulate their expression and alter neurogenesis. BFLS mice exhibit altered NSC and progenitor populations, and deregulation of Ephrin receptors. EphR-A family of receptors rescues PHF6 loss-of-function defects in BFLS mice-derived eNSCs. This study reveals genome wide binding of PHF6 in the developing cortex and shows that it alters neural stem cells via regulation of Ephrin receptors. PHF6/EphR pathway is impaired in the rare X-linked intellectual disability, BFLS. [ABSTRACT FROM AUTHOR]

The function and maintenance of muscle stem cells (MuSCs) are tightly regulated by signals originating from their niche environment. Skeletal myofibers are a principle component of the MuSC niche and are in direct contact with the muscle stem cells. Here, we show that Myf6 establishes a ligand/receptor interaction between muscle stem cells and their associated muscle fibers. Our data show that Myf6 transcriptionally regulates a broad spectrum of myokines and muscle‐secreted proteins in skeletal myofibers, including EGF. EGFR signaling blocks p38 MAP kinase‐induced differentiation of muscle stem cells. Homozygous deletion of Myf6 causes a significant reduction in the ability of muscle to produce EGF, leading to a deregulation in EGFR signaling. Consequently, although Myf6‐knockout mice are born with a normal muscle stem cell compartment, they undergo a progressive reduction in their stem cell pool during postnatal life due to spontaneous exit from quiescence. Taken together, our data uncover a novel role for Myf6 in promoting the expression of key myokines, such as EGF, in the muscle fiber which prevents muscle stem cell exhaustion by blocking their premature differentiation. Synopsis: Skeletal muscle fibers are a key signaling component of the muscle stem cell niche. Myf6‐induced expression of myokines in skeletal muscle maintains myofiber‐associated muscle stem cell pools by blocking their premature differentiation in adult mice. Myf6 transcriptionally promotes the expression of a vast array of myokines such as Epidermal Growth Factor EGF and VEGFA in the myofibers of adult mice.Genetic deletion of Myf6 impairs the activation of the EGFR signaling pathway in satellite cells.Mice with a homozygous deletion of Myf6 are born normal. However, Muscle stem cells from Myf6‐knockout mice spontaneously break from quiescence, activate p38 MAPK and enter into myogenic differentiation in resting adult mouse muscle. [ABSTRACT FROM AUTHOR]

Superior to linear peptides in biological activities, cyclic peptides are considered to have great potential as therapeutic agents. To identify cyclic‐peptide ligands for therapeutic targets, phage‐displayed peptide libraries in which cyclization is achieved by the covalent conjugation of cysteines have been widely used. To resolve drawbacks related to cysteine conjugation, we have invented a phage‐display technique in which its displayed peptides are cyclized through a proximity‐driven Michael addition reaction between a cysteine and an amber‐codon‐encoded Nϵ‐acryloyl‐lysine (AcrK). Using a randomized 6‐mer library in which peptides were cyclized at two ends through a cysteine–AcrK linker, we demonstrated the successful selection of potent ligands for TEV protease and HDAC8. All selected cyclic peptide ligands showed 4‐ to 6‐fold stronger affinity to their protein targets than their linear counterparts. We believe this approach will find broad applications in drug discovery. [ABSTRACT FROM AUTHOR]

Densifying the communications network and integrating innovative technologies leads to increased power consumption (PC), along with increased signalling and degraded scalability. The latter can be mitigated by using software defined networks, while cloud radio access network (C-RAN) reduces the PC. Since evaluating and improving the PC is an important key success factor for the upcoming fifth generations, a reliable power model (PM) is required. This study proposes a componentised, linear and parameterised PM, and explores the individual components relevant for PC analysis, particularly for software defined C-RAN (SDC-RAN) architecture. The model quantifies the energy efficiency (EE) by capturing the PC of individual components, and measures the amount of PC in the network. Cooling and total PC of C-RAN and SDC-RAN for different parameters such as varying numbers of antennas and different system's bandwidth share has also been considered. The results show that SDC-RAN increases the total PC by about 20% compared with C-RAN. Additionally, the study shows the results of modelling the participating core network's control plane unit's PC along with establishing the accuracy of the components and the parameterised models. [ABSTRACT FROM AUTHOR]

Background Bullous pemphigoid is an autoimmune subepidermal blistering skin and mucous membrane disease that usually occurs in elderly people. This study was done to determine clinical features, paraclinical findings, incidence of mucosal lesions, prognosis, course of the disease, and mortality rate of patients with bullous pemphigoid. Method Retrospective descriptive study that reviews the existing files of 122 patients with bullous pemphigoid referred to dermatology clinics of Ghaem and Imam Reza hospitals in Mashhad, Iran, from 1995 to 2010. Result The majority of patients were aged between 60 and 79 years, and 53% of them were women. The major prodromal lesions were erythematous and urticarial (36.8%) and eczematous lesions (32.7%); 84.3% of patients complained of pruritus, and mucosal lesions were observed in 31.1% of patients (all in the oral mucosa). The most frequent concurrent diseases with pemphigoid were hypertension and diabetes mellitus. Conclusion Clinical features, paraclinical findings, incidence of mucosal lesions, prognosis, course of the disease, and mortality rate of bullous pemphigoid in the Khorasan region were approximately similar to results from other regions. [ABSTRACT FROM AUTHOR]

A 3 × 4 factorial design was used to evaluate the dietary protein requirement and to determine the optimum dietary protein to energy ( P/DE) ratio in sub-yearling Persian sturgeon, Acipenser persicus, reared in the indoor system. Twelve experimental diets (40P16, 40P17, 40P18, 40P19, 45P19, 45P17, 45P18, 45P19, 50P16, 50P17, 50P18 and 50P19) were formulated and prepared to contain three protein levels (40%, 45% and 50%) and four digestible energy levels (16, 17, 18 and 19 kJ g−1 diet) at each protein level. Fish averaging 103.3 ± 3.5 (mean ± SD) were fed one of the experimental diets for 14 weeks. At the end of the experimental period, there were significant energy effects ( P < 0.05) on weight gain ( WG) and specific growth rate ( SGR). Weight gain and SGR tended to decrease, although non-significantly, with increase in dietary protein levels. Furthermore, there were significant protein and energy interaction effects on WG, SGR, hepatosomatic index and protein efficiency ratio. However, there were no significant dietary protein, energy or their interaction effects on feed efficiency for fish fed all diets. Weight gain and SGR of fish fed 40P19 were significantly higher than those of fish fed 40P16, 45P16, 45P17, 50P16 and 50P17 diets ( P < 0.05). There were no significant differences in WG and SGR among fish fed 40P17, 40P18, 40P19, 45P18, 45P19, 50P18 and 50P19 diets. These results may indicate that the optimum dietary protein requirement and the P/DE ratio could be 40% protein and 22.0 mg protein kJ−1 (40P18), respectively, in Persian sturgeon, based on growth performance and feed utilization. [ABSTRACT FROM AUTHOR]

Introduction – Neurocysticercosis (NCC) is the most common helminthic infection of the central nervous system. It is a major public health problem in developing countries, however, rarely reported in Saudi Arabia. As far as our knowledge, this is the first case report of NCC in Saudi Arabia. An increasing number of immigrants from endemic areas is the cause. Case Reports – Here, we report three interesting cases of NCC in three adult females with very unusual clinical presentation. These include: (case 1) progressive spasticity of the four limbs with severe pseudobulbar manifestations, precipitancy of micturition, cognitive impairment and no eye involvement; (case 2) dystonic movement of right upper and lower limbs together with weight gain, lethargy, mental dullness and goitre; and (case 3) depressive manifestations together with disturbance of writing, mild deep sensory loss, limb-kinetic apraxia, lack of coordination and dystonia of the right upper limb. The clinical details and possible mechanisms for the uncommon presentations are discussed. Conclusion – NCC should be kept in mind and raise a high level of suspicion for unusual neurological manifestations in Saudian patients particularly as there has been increasing percentage of immigration from endemic areas during the last few years. [ABSTRACT FROM AUTHOR]

Objective – To explore the reproductive conditions in women with epilepsy. Methods – Eighty-eight women were included; 37.5% and 62.5% had generalized and partial epilepsies, respectively. Ovarian sonogram, reproductive hormone and lipid profiles were assessed. Results – Compared with the control group and in accordance with our laboratory reference values, irregular menses and polycystic ovaries (PCO(s)) were reported in 70.5% and 39.8% versus 21.7% and 16.7% of controls. Abnormalities in leutinizing hormone (LH), follicle-stimulating hormone (FSH), LH-to-FSH ratio, testosterone (T) and prolactin (PRL) were identified. High values of FSH, LH and FSH-to-LH ratio were common with carbamazepine while that of T and PRL were common in untreated patients and with valproate. Low levels of high-density lipoprotein cholesterol was identified in ∼59% but neither associated with duration and type of antiepileptic drugs nor patients’ age, hormonal profile or PCO(s). Significant correlation was identified between menatrual irregularities, T, PRL, hormonal, lipid profile alterations, PCO(s) and seizure frequency but neither with epilepsy type nor focus. Conclusion – This is the first study in our country that aimed at evaluation of reproductive conditions in women with epilepsy. This study indicates that reproductive dysfunction is common, hence, characterization of seizure-associated neuroendocrine adverse effects is important while managing women particularly during choice of antiepileptic medications as initial step and during patients’ follow-up. [ABSTRACT FROM AUTHOR]

Objective – Acetyl choline (ACh) is the main neurotransmitter of the efferent auditory system. This study is aimed to evaluate cochlear function in myasthenia gravis (MG), a neuromuscular transmission disorder caused by ACh receptor autoantibodies. Methods – This prospective study included 16 myasthenic patients, tested audiologically twice, first after improvement from myasthenic crisis or acute oropharyngeal dysfunction (1 week from admission) and then 2 months later. We detected the effect of contralateral acoustic stimulation (CAS) on patients’ transient and distortion product otoacoustic emissions (TEOAE and DPOAE). Results – Compared with controls, patients reported significant reduction in overall echo response and amplitude of TEOAEs at 1–2 kHz and at 1–6 kHz of DPOAE with marked reduction at 5 kHz. In the control group, CAS produced amplitude reduction in TEOAEs and DPOAEs at 1–4 kHz. Utilizing masking effect, patients reported amplitude reduction in TEOAEs at 1.5–4 kHz while DPOAEs did not reach significant level except at 1.5 and 5 kHz. After 2 months, no changes were observed compared with early assessment. Conclusions – It is clear that disease progression is associated with irreversible cochlear damage. Lack of improvement in patients’ emissions despite partial non-audiometric improvement in relation to receptors needs to be considered. [ABSTRACT FROM AUTHOR]

Hamed SA, Sutherland-Smith AJ, Gorospe JRM, Kendrick-Jones J, Hoffman EP. DNA sequence analysis for structure/function and mutation studies in Becker muscular dystrophy.We systematically screened the whole coding region of 18 male muscular dystrophy patients whose clinical, histological and laboratory findings suggest Becker muscular dystrophy (present but abnormal dystrophin). No systematic mutation study of a cohort of patients with dystrophin of normal quality but abnormal quantity has been published. The complete coding sequence of the dystrophin gene (11 kb) of each patient was subjected to an automated sequence analysis by using muscle biopsy RNA; 535 bp of the gene promoter and 5′UTR were likewise sequenced. We identified seven disease-causing mutations (40%). Six were novel, including missense, nonsense, small deletion and splice site mutations. Sixty percent (11/18) of patients with decreased quantities of normal molecular weight dystrophin showed no mutation, but most of them had a family history highly suggestive of X-linked inheritance, suggesting transcription or translational deleterious affection, i.e. outside what was screened. Quantitative multiplex fluorescence polymerase chain studies of mutation-negative patients showed normal levels of dystrophin mRNA. In three patients, there was some reduction of the transcript suggesting a deleterious undetected gene change resulted in the reduction of RNA levels. Our data address important structure/function and genotype/phenotype correlations and it suggests that dystrophin protein studies must be interpreted with caution in deletion-negative male muscular dystrophy patients. [ABSTRACT FROM AUTHOR]

Surgical resection of persistent/recurrent (P/R) papillary thyroid cancer (PTC), when localized to the neck, is generally recommended; however, its impact on the course of the disease is not clear. We introduced a new technique in the form of preoperative neck ultrasonographic mapping (US-M) to improve the outcome of the surgical resection of P/R PTC. A total of 19 patients had undergone regional (central, lateral, or both) neck dissection before introducing the current technique (group 1, or G1), and 26 patients (group 2, or G2) had limited lymph node resection guided by US-M with findings accurately plotted on a standard diagram. All of the operations were performed by a single surgeon. The surgical outcomes of the two groups were compared. The resected lesions were positive for PTC in 17 patients (89.5%) in G1 and in 25 patients (96.2%) in G2. In G2, the intraoperative findings exactly matched the US-M in 23 patients (88.5%). Postoperatively, neck US became negative in 50% in G1 and in 83.3% in G2 (p= 0.02). Thyroglobulin (Tg) became undetectable in 37.5% in G1 and 52.3% in G2 (p= 0.37). Whole-body iodine scans (WBS) became negative in one of six patients (16.7%) in G1, and in three of four patients (75%) in G2, (p= 0.06). After a mean follow-up of 23.8 ± 7.1 months in G1 and 9.8 ± 4.7 months in G2, 6 patients (31.6%) in G1 and 15 patients (62.5%) in G2 were in remission (p= 0.04), whereas the disease persisted in 13 cases (68.4%) in G1 and 9 (37.5%) in G2 (p= 0.04). In conclusion, US-M improved the surgical outcome, as evidenced by the postoperative US, Tg, and WBS findings and the higher remission rate for the G2 patients than for the G1 patients. [ABSTRACT FROM AUTHOR]

SUMMARY 1. The present study was designed to assess the effect of the tetradecapeptide somatostatin on the GABAA receptor complex in the rat hypothalamus. 2. GABAA receptors were labelled with [35 S]-tert-butylbicyclophosphorothionate (TBPS), which binds in or near the chloride channel, and binding as assessed by in vitro quantitative autoradiography using a computer-assisted image analysis system. 3. Somatostatin inhibited the binding of [35 S]-TBPS to the convulsant site of the hypothalamic GABAA receptor complex of rat slide-mounted hypothalamic structures in a concentration-dependent manner with an affinity in the micromolar range (10–6 to 3 × 10–6 mol/L). Somatostatin appeared to mimic the effects of the neurosteroid 5α -pregnane-3α ol-one (5α 3α P), GABA and picrotoxin on [35 S]-TBPS binding in the rat hypothalamus in all structures examined. Furthermore, GABA or muscimol (a GABAA receptor agonist), when added to the incubation medium, enhanced the capacity of somatostatin to inhibit [35 S]-TBPS binding, with an IC50 of 10–7 mol/L. However, incubation with bicuculline (a GABAA receptor antagonist) led to the abolition of the inhibitory effect of somatostatin on [35 S]-TBPS specific binding in rat hypothalamus. 4. The present results demonstrate the presence of a modulatory effect of somatostatin on the GABAA receptor complex in rat hypothalamic structures. Furthermore, the data suggest that somatostatin allosterically modifies [35 S]-TBPS binding through a mechanism similar to that of GABA. Taken together, these results provide evidence for the presence of somatostatin– GABA interactions in rat hypothalamus. [ABSTRACT FROM AUTHOR]

The effects of drought on growth, pigments and 14CO2 assimilation were studied in three sorghum cultivars. Water stress applied either at the vegetative or at the reproductive stage was found to reduce relative growth and net assimilation rates. Root growth was less affected by water stress and in certain cases it was increased; consequently, the root/shoot ratio was improved. The sensitivity to drought stress was greater at the reproductive than at the vegetative stage. Dorado was the most drought-tolerant and Giza 15 the least drought-tolerant cultivar, as determined by calculation of the drought susceptibility index for total green leaf area and shoot dry weight. Short-term water stress in the vegetative phase (7 days) improved the chlorophyll content in leaves, and long-term stress in the vegetative and reproductive phases reduced chlorophyll content. Carotenoid content, in general, was not changed by drought stress. 14CO2 photoassimilation indicated that soluble, insoluble and consequently total photosynthates were reduced at the end of the stress period at both stages. Drought plus defoliation appeared to increase both chlorophyll content and 14CO2 photoassimilation, to a certain extent, as compared with drought alone. [ABSTRACT FROM AUTHOR]

The export and translocation of radioactivity supplied as 14C-auxin or as a 14C-kinin to a donor leaf of cocoa was followed at different stages of the flush cycle to see whether there was any correlation between the pattern of movement of these growth promoters and apical bud activity. The auxin 3-indole (1-14C) acetic acid, (14C-IAA), and the cytokinin, 6-benzyl-amino (8-14C) purine, (14C-BAP), were introduced into the plant by foliar feeding. Export of the radioactivity derived from the 14C-IAA was predominantly basipetal at all stages of the flush cycle. Most of the tracer accumulated in the lower stem but there was a significantly high proportion in the older leaves. It appeared that the largest proportion of the radioactivity derived from 14C-IAA was found in parts of the plant where growth, or possibly carbohydrate accumulation, was active.. It is suggested that the movement of 14C-IAA and its metabolites in cocoa may be largely determined by the direction of flow of the assimilate stream. The identity of the radioactive compounds exported from the donor leaf showed that some 80% of the fed 14C-IAA was metabolized to other indole compounds including indole aldehyde, indole aspartate and indole acetonitrile. When the 14C present in particular plant parts was expressed as a relative radioactivity ratio, this value, for the apical bud, declined throughout the flush cycle, being highest at bud break, indicating that the capacity of the- bud to accumulate radioactivity derived from 14C-IAA was greatest during the stages of leaf production. The distribution of radioactivity from 14C-BAP indicated both acropetal and basipetal transport of cytokinin but accumulation of radioactivity occurred only in actively growing regions. Unlike 14C-IAA, the 14C-BAP exported from the leaf was not extensively metabolized and about 60% of the transported radioactivity was detected as 14C-BAP and the remainder as conjugated 14C-BAP . For this compound the relative radioactivity ratio in the bud was highest at dormacy break (F-1), suggesting that cytokinin movement to the bud was related to the breaking of dormacy. The changes in pattern of transport of auxin and cytokinin throughout the cocoa plant were correlated with the stages of the flush cycle. [ABSTRACT FROM AUTHOR]

The flush leaves of seedling cocoa plants were assessed at each stage of the flush cycle from leaf unfolding to maturity for differences in leaf lamina presentation angle, surface hairs, stomatal number and development and leaf cuticle thickness. Changes in these parameters were then correlated with cuticular and stomatal diffusive resistance of the leaves. It is suggested that perpendicular positioning of the young flush leaves, the presence of surface hairs, the rapid synthesis of the cuticle and the limited stomatal development during the early stages of leaf expansion, restrict water loss from the developing leaves. Maximum rate of water loss from the leaves of a new flush was only attained after leaves were fully expanded, stomata fully developed and the leaves horizontally positioned. It is suggested that the large increase in water loss from the flush leaves following these changes might lead to an internal water deficit in the plant and hence to increased synthesis of abscisic acid in the shoot which, in turn, will maintain dormancy of the shoot apex in at least part of the interflush period. [ABSTRACT FROM AUTHOR]

The dormant phase of the flush cycle of leaf growth in cocoa is known to be correlated with high abscisic acid (ABA) levels in the mature leaves of the new flush (NF) and previous flush (PF) leaves. Defoliation of either the NF leaves or PF leaves of cocoa seedlings reduced the length of the dormant phase of the flush cycle, thus showing that the mature leaves were a source of growth inhibitors which could affect shoot apical activity. The application of ABA to the NF and PF leaves led to an extension of the dormant phase, whereas application of zeatin or gibberellic acid decreased it The distribution of [14C]ABA following its application to NF and PF leaves at different stages throughout the growth cycle showed that [14C]ABA was accumulated by the bud in relatively larger amounts during the final stages of bud dormancy (I-1 and I-2) than in the earlier stage (F-2). The results suggest that internal competition for nutrients may be responsible for the inhibition of growth at the F-2 stage but that ABA translocated from the mature leaves causes the buds to remain dormant during the subsequent stages of I-1 and I-2. [ABSTRACT FROM AUTHOR]

Focuses on the alteration of the allosteric modulation of the GABA[sub A] receptor in rat hypothalamus by somatostatin by stress. Label of GABA[sub A]; Increase of the [[sup 35]S]-t-butylbicyclophosphorothionate binding in the several structures of the rat hypothalamus.

Social communication draws on several cognitive functions such as perception, emotion recognition and attention. The association of audio-visual information is essential to the processing of species-specific communication signals. In this study, we use functional magnetic resonance imaging in order to identify the subcortical areas involved in the cross-modal association of visual and auditory information based on their common social meaning. We identified three subcortical regions involved in audio-visual processing of species-specific communicative signals: the dorsolateral amygdala, the claustrum and the pulvinar. These regions responded to visual, auditory congruent and audio-visual stimulations. However, none of them was significantly activated when the auditory stimuli were semantically incongruent with the visual context, thus showing an influence of visual context on auditory processing. For example, positive vocalization (coos) activated the three subcortical regions when presented in the context of positive facial expression (lipsmacks) but not when presented in the context of negative facial expression (aggressive faces). In addition, the medial pulvinar and the amygdala presented multisensory integration such that audiovisual stimuli resulted in activations that were significantly higher than those observed for the highest unimodal response. Last, the pulvinar responded in a task-dependent manner, along a specific spatial sensory gradient. We propose that the dorsolateral amygdala, the claustrum and the pulvinar belong to a multisensory network that modulates the perception of visual socioemotional information and vocalizations as a function of the relevance of the stimuli in the social context. SIGNIFICANCE STATEMENT: Understanding and correctly associating socioemotional information across sensory modalities, such that happy faces predict laughter and escape scenes predict screams, is essential when living in complex social groups. With the use of functional magnetic imaging in the awake macaque, we identify three subcortical structures-dorsolateral amygdala, claustrum and pulvinar-that only respond to auditory information that matches the ongoing visual socioemotional context, such as hearing positively valenced coo calls and seeing positively valenced mutual grooming monkeys. We additionally describe task-dependent activations in the pulvinar, organizing along a specific spatial sensory gradient, supporting its role as a network regulator., (© 2024 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

Attentional processes allow the brain to overcome its processing capacities limitations by enhancing relevant visual information and suppressing irrelevant information. Thus attention plays a critical role, shaping our perception of the world. Several models have been proposed to describe the neuronal bases of attention and its mechanistic underlyings. Recent electrophysiological evidence show that attentional processes rely on oscillatory brain activities that correlate with rhythmic changes in cognitive performance. In the present review, we first take a historical perspective on how attention is viewed, from the initial spotlight theory of attention to the recent dynamic view of attention selection and we review their supporting psychophysical evidence. Based on recent prefrontal electrophysiological evidence, we refine the most recent models of attention sampling by proposing a rhythmic and continuous model of attentional sampling. In particular, we show that attention involves a continuous exploration of space, shifting within and across visual hemifield at specific alpha and theta rhythms, independently of the current attentional load. In addition, we show that this prefrontal attentional spotlight implements conjointly selection and suppression mechanisms, and is captured by salient incoming items. Last, we argue that this attention spotlight implements a highly flexible alternation of attentional exploration and exploitation epochs, depending on ongoing task contingencies. In a last part, we review the local and network oscillatory mechanisms that correlate with rhythmic attentional sampling, describing multiple rhythmic generators and complex network interactions., (© 2020 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

The goal of executive control is to adjust our behaviour to the environment. It involves not only the continuous planning and adaptation of actions but also the inhibition of inappropriate movements. Recently, a proactive form of inhibitory control has been shown, demonstrating that actions can be withheld, in an uncertain environment, thanks to the proactive locking of the mechanism by which motor commands are triggered (e.g. while waiting at traffic lights in a dense pedestrian zone, one will refrain in anticipation of a brisk acceleration when the green light comes on). However, little is known about this executive function and it remains unclear whether the overall amount of inhibitory control can be modulated as a function of the context. Here, we show that the level of this control varies parametrically as a function of the exogenous and endogenous factors setting the task context. We also show that the level of implemented proactive inhibitory control is dynamically readjusted to match the implicit temporal structure of the environment. These observations are discussed in relation to possible underlying functional substrates and related neurological and psychiatric pathologies., (© 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.)

The anterior wall of the parieto-occipital sulcus (POs) of the macaque monkey, classically considered as part of Brodmann's area 19, contains two functionally distinct areas: a ventral, purely visual area, V6, and a dorsal area, V6A, containing visual neurons and neurons related to the control of arm movements. The aim of this study was to establish whether areas V6 and V6A, so far identified only on a functional basis, have a cytoarchitectonic counterpart. The cytoarchitectonic analysis of 13 hemispheres from ten macaque brains, cut along different planes of section, showed that the anterior wall of the POs contains three distinct areas. One is located in the ventralmost part of the wall, another in the dorsalmost part of the wall, and the third occupies an intermediate position. The ventralmost region displays architectonic features typical of the occipital cytoarchitectonic domain, whereas the two dorsal areas display architectonic features typical of the posterior parietal cortex. Analysis of myeloarchitecture and of the distribution of SMI-32 immunoreactivity confirmed the cytoarchitectonic parcellation. Correlation of cytoarchitectonic maps with functional and hodological data strongly suggests that the ventral region corresponds to area V6, whereas the other two regions correspond to different subsectors of V6A, here named V6Av and V6Ad, respectively. The present data are in line with electrophysiological and hodological data, which suggest that area V6 is a classic extrastriate area, whereas V6A is an area of the posterior parietal cortex. They also suggest that V6A includes two separate cortical subdivisions, a view supported by preliminary functional and hodological data that needs further confirmation.

We recorded neuronal responses to optic flow stimuli in the ventral intraparietal area (VIP) of two awake macaque monkeys. According to previous studies on optic flow responses in monkey extrastriate cortex we used different stimulus classes: frontoparallel motion, radial stimuli (expansion and contraction) and rotational stimuli (clockwise and counter-clockwise). Seventy-five percent of the cells showed statistically significant responses to one or more of these optic flow stimuli. Shifting the location of the singularity of the optic flow stimuli within the visual field led to a response modulation in almost all cases. For the majority of neurons, this modulatory influence could be approximated in a statistically significant manner by a two-dimensional linear regression. Gradient directions, derived from the regression parameters and indicating the direction of the steepest increase in the responses, were uniformly distributed. At the population level, an unbiased average response for the stimuli with different focus locations was observed. By applying a population code, termed 'isofrequency encoding', we demonstrate the capability of the recorded neuronal ensemble to retrieve the focus location from its population discharge. Responses to expansion and contraction stimuli cannot be predicted based on quantitative data on a neuron's frontoparallel preferred stimulus direction and the location and size of its receptive field. These results, taken together with data on polymodal motion responses in this area, suggest an involvement of area VIP in the analysis and the encoding of heading.

Self-motion detection requires the interaction of a number of sensory systems for correct perceptual interpretation of a given movement and an eventual motor response. Parietal cortical areas are thought to play an important role in this function, and we have thus studied the encoding of multimodal signals and their spatiotemporal interactions in the ventral intraparietal area of macaque monkeys. Thereby, we have identified for the first time the presence of vestibular sensory input to this area and described its interaction with somatosensory and visual signals, via extracellular single-cell recordings in awake head-fixed animals. Visual responses were driven by large field stimuli that simulated either backward or forward self-motion (contraction or expansion stimuli, respectively), or movement in the frontoparallel plane (visual increments moving simultaneously in the same direction). While the dominant sensory modality in most neurons was visual, about one third of all recorded neurons responded to horizontal rotation. These vestibular responses were typically in phase with head velocity, but in some cases they could signal acceleration or even showed integration to position. The associated visual responses were always codirectional with the vestibular on-direction, i.e. noncomplementary. Somatosensory responses were in register with the visual preferred direction, either in the same or in the opposite direction, thus signalling translation or rotation in the horizontal plane. These results, taken together with data on responses to optic flow stimuli obtained in a parallel study, strongly suggest an involvement of area VIP in the analysis and the encoding of self-motion.

1. The present study was designed to assess the effect of the tetradecapeptide somatostatin on the GABA(A) receptor complex in the rat hypothalamus. 2. GABA(A) receptors were labelled with [35S]-tert-butylbicyclophosphorothionate (TBPS), which binds in or near the chloride channel, and binding as assessed by in vitro quantitative autoradiography using a computer-assisted image analysis system. 3. Somatostatin inhibited the binding of [35S]-TBPS to the convulsant site of the hypothalamic GABA(A) receptor complex of rat slide-mounted hypothalamic structures in a concentration-dependent manner with an affinity in the micromolar range (10(-6) to 3 x 10(-6) mol/L). Somatostatin appeared to mimic the effects of the neurosteroid 5alpha-pregnane-3alpha ol-one (5alpha3alphaP), GABA and picrotoxin on [35S]-TBPS binding in the rat hypothalamus in all structures examined. Furthermore, GABA or muscimol (a GABA(A) receptor agonist), when added to the incubation medium, enhanced the capacity of somatostatin to inhibit [35S]-TBPS binding, with an IC50 of 10(-7) mol/L. However, incubation with bicuculline (a GABA(A) receptor antagonist) led to the abolition of the inhibitory effect of somatostatin on [35S]-TBPS specific binding in rat hypothalamus. 4. The present results demonstrate the presence of a modulatory effect of somatostatin on the GABA(A) receptor complex in rat hypothalamic structures. Furthermore, the data suggest that somatostatin allosterically modifies [35S]-TBPS binding through a mechanism similar to that of GABA. Taken together, these results provide evidence for the presence of somatostatin- GABA interactions in rat hypothalamus.