The visual system of Drosophila is an excellent model for determining the interactions that direct the differentiation of the nervous system's many unique cell types. Glia are essential not only in the development of the nervous system, but also in the function of those neurons with which they become associated ...

Amblyopia is one of the most common forms of visual impairment, arising from an early functional imbalance between the two eyes. It is currently accepted that, due to a lack of neural plasticity,amblyopia is an untreatable pathology in adults. Environmental enrichment (EE) emerged as a strategy highly effective in restoring ...

The mature optic nerve cannot regenerate when injured, leaving victims of traumatic nerve damage or diseases such as glaucoma with irreversible visual losses. Recent studies have identified ways to stimulate retinal ganglion cells to regenerate axons part-way through the optic nerve, but it remains unknown whether mature axons can reenter ...

A clinically effective retinal prosthesis must evoke localized phosphenes in a retinotopic manner in response to stimulation of each of the retinal electrodes, evoke brightness cues over a wide dynamic range and function within safe stimulus limits. The effects of varying return configuration for retinal stimulation are currently unknown. To ...

Open angle glaucoma is an optic neuropathy that has a multifarious aetiological profile. Emerging theories suggest that a group of factors induce optic nerve injury in innately susceptible aging optic nerves. These factors have the potential to impact on the function of other vulnerable neurons within the central nervous system ...

OBJECTIVE: The posterior subthalamic area (PSA) is an emerging but relatively unexplored target for DBS treatment of tremor. The aim of the study was to explore the area further by evaluating the spatial distribution and the characteristics of stimulation-induced side effects in this area. METHODS: Twenty-eight patients with essential tremor ...

Neurons in the isthmo-optic nucleus (ION) of the avian midbrain receive input predominantly from the ipsilateral optic tectum and project to the contralateral retina. Therefore, lesion in the ION removes tectal efferent signals to the retina in birds. In the present study, we trained Japanese quail to reach a target ...

The cation-Cl(-) cotransporters participate to neuronal Cl(-) balance and are responsible for the post-natal Cl(-) switch in central neurons. In the adult peripheral nervous system, it is not well established whether a Cl(-) transition occurs during maturation. We investigated the contribution of cation-Cl(-) cotransporters in the Cl(-) handling of sensory ...

Transcranial magnetic stimulation (TMS) noninvasively interferes with human cortical function, and is widely used as an effective technique for probing causal links between neural activity and cognitive function. However, the physiological mechanisms underlying TMS-induced effects on neural activity remain unclear. We examined the mechanism by which TMS disrupts neural activity ...

The cortical processing of illusory contours provides a unique window for exploring the brain mechanisms underlying visual perception. Previous electrophysiological single-cell recordings demonstrate that a subgroup of cells in macaque V1 and V2 signal the presence of illusory contours, whereas recent human brain imaging studies reveal higher-order visual cortices playing ...

The bottom-up processing of visual information is strongly influenced by top-down signals, at least part of which is thought to be conveyed from the frontal cortex through the frontal eye field (FEF) and the lateral intraparietal area (LIP). Here we investigated the architecture of multisynaptic pathways from the frontal cortex ...

Sound localization in both humans and monkeys is tolerant to changes in sound level. The underlying neural mechanism, however, is not well understood. This study reports the level dependence of individual neurons' spatial receptive field (SRF) in the primary auditory cortex (A1) and adjacent caudal field in awake marmoset monkeys. ...

Purpose: The primary motor cortex is capable of rapid, reversible plastic changes and longer-term, more permanent reorganization. Ischemic nerve block (INB) is a model of deafferentation-induced short-term plasticity. We used transcranial magnetic stimulation to examine whether changes in the excitability of short- and/or long-interval intracortical inhibitory (SICI, LICI) or short-interval ...

In multimodal integration and sensorimotor transformation areas of the posterior parietal cortex (PPC), neural responses often appear encoded in spatial reference frames that are intermediate to the intrinsic sensory reference frames, for example, eye-centered for visual or head-centered for auditory stimulation. Many sensory responses in these areas are also modulated ...

The number of surviving spiral ganglion neurons (SGNs) is important for the function of cochlear implants. Electrical stimulation has been discussed controversially regarding its protective effects on SGNs both in vivo and in vitro. The aim of this study was to develop a device for electrical stimulation of cultured SGNs. ...

Many methods used to analyze neuronal response assume that neuronal activity has a fundamentally linear relationship to the stimulus. However, some neurons are strongly sensitive to multiple directions in stimulus space and have a highly nonlinear response. It can be difficult to find optimal stimuli for these neurons. We demonstrate ...

Understanding color vision requires knowing how signals from the three classes of cone photoreceptor are combined in the cortex. We recorded from individual neurons in the primary visual cortex (V1) of awake monkeys while an automated, closed-loop system identified stimuli that differed in cone contrast but evoked the same response. ...

Expertise in non-visual domains such as musical performance is associated with differences in gray matter volume of particular regions of the human brain. Whether this is also the case for expertise in visual object recognition is unknown. Here we tested whether individual variability in the ability to recognize car models, ...

Tetanus neurotoxin (TeNT) is a metalloprotease that cleaves the synaptic protein VAMP/synaptobrevin, leading to focal epilepsy. Although this model is widely used in rats, the time course and spatial specificity of TeNT proteolytic action have not been precisely defined. Here we have studied the biochemical, electrographic, and anatomic characteristics of ...

Thirteen chronic tinnitus patients and fifteen age-matched healthy controls were studied on a 3T MRI scanner during resting condition (i.e. eyes closed, no task performance). The auditory resting-state component was selected using an automatic component selection approach. Functional connectivity (correlations/anti-correlations) in the extracted network was portrayed by integrating the ICA ...

Exploration of neural sources and their effective connectivity based on transient changes in electrophysiological activities to external stimuli is important for understanding brain mechanisms of sensory information processing. However, such cortical mechanisms have not yet been well characterized in electrophysiological studies since (1) it is difficult to estimate the stimulus-activated ...

Somatosensory evoked potentials (SSEPs) are a sensitive quantitative measure of conduction in somatosensory pathways of the central nervous system and are increasingly used in both clinical trials and animal experiments. SSEPs can be recorded in non-sedated rodents by magnetic stimulation (MS) of peripheral nerves. To overcome some disadvantages caused by ...

Experience-dependent plasticity is closely linked with the development of sensory function. Beyond this sensitive period, developmental plasticity is actively limited; however, new studies provide growing evidence for plasticity in the adult visual system. The amblyopic visual system is an excellent model for examining the "brakes" that limit recovery of function ...

Neurons at the top of primate ventral visual stream [inferior temporal cortex (IT)] have selectivity for objects that is highly tolerant to variation in the object's appearance on the retina. Previous nonhuman primate (Macaca mulatta) studies suggest that this neuronal tolerance is at least partly supported by the natural temporal ...

New research suggests that auditory stimuli can reset human oscillatory activity in visual cortex. This change in rhythmical brain activity leads to modulation of visual perception.

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 not well understood. We manipulated lateral pulvinar neural activity in prosimian primates and assessed ...

The effect of gender on the N1-P2 auditory complex was examined while listening and speaking with altered auditory feedback. Fifteen normal hearing adult males and 15 females participated. N1-P2 components were evoked while listening to self-produced nonaltered and frequency shifted /a/ tokens and during production of /a/ tokens during nonaltered ...

The neuronal ceroid lipofuscinoses constitute the most common group of childhood neurodegenerative disorders. These devastating disorders still remain without effective treatment. The use of animal models has provided significant information about NCL pathogenesis, highlighting early glial activation and neuron loss in specific brain regions of affected animals. Here, we have ...

Visual neurons are known to synchronize their firing with stimuli that flicker at a constant rate (e.g., 12Hz). These so-called visual steady-state responses (VSSR) are a well-studied phenomenon, yet the underlying mechanisms are widely disagreed upon. Furthermore, there is limited evidence that visual neurons may simultaneously synchronize at harmonics of ...

ABSTRACT: To radiologically evaluate the anatomic factors that may determine the view field or the accessibility of the posterior tympanotomy into the posterior mesotympanum, a cohort of 30 patients with pneumatic mastoids and 30 patients with unilateral sclerotic mastoids were included. Anatomic relationships were evaluated according to 5 parameters. The ...

Is a short visuo-motor associative training sufficient to reverse the visuo-motor tuning of mirror neurons in adult humans? We tested the effects of associative training on cortico-spinal modulation during action observation in the 100-320 ms interval after action onset. In two separate experiments, the acceleration of transcranial magnetic stimulation (TMS)-induced ...

The mammalian cerebral cortex, which is stratified into six layers, has functional domains that vertically span the six layers, thereby requiring tight interlaminar connectivity within a domain. The synaptic connections in individual layers are first broadly formed under predetermined programs and later reinforced between neurons which reside in the same ...

Accumulating empirical evidence suggests a role of Bayesian inference and learning for shaping neural responses in auditory and visual perception. However, its relevance for somatosensory processing is unclear. In the present study we test the hypothesis that cortical somatosensory processing exhibits dynamics that are consistent with Bayesian accounts of brain ...

Studying the insect visual system provides important data on the basic neural mechanisms underlying visual processing. As in vertebrates, the first step in visual processing in insects is through a series of retinotopic neurons. Recent studies on flies have found that these converge onto assemblies of columnar neurons in the ...

Many mammals rely on pheromones for mediating social interactions. Recent studies indicate that both the main olfactory system (MOS) and accessory olfactory system (AOS) detect and process pheromonal stimuli, yet the functional difference between these two chemosensory systems remains unclear. We hypothesized that the main functional distinction between the MOS ...

Signal duration is important for identifying sound sources and determining signal meaning. Duration-tuned neurons (DTNs) respond preferentially to a range of stimulus durations and maximally to a best duration (BD). Duration-tuned neurons are found in the auditory midbrain of many vertebrates, although studied most extensively in bats. Studies of DTNs ...

The right posterior parietal cortex (rPPC) has been found to be critical in shaping visual selection and distractor-induced saccade curvature in the context of predictive as well as non-predictive visual cues by means of TMS interference. However, the dynamic details of how distractor-induced saccade curvatures are affected by rPPC TMS ...

The central auditory system consists of the lemniscal and nonlemniscal pathways or systems, which are anatomically and physiologically different from each other. In the thalamus, the ventral division of the medial geniculate body (MGBv) belongs to the lemniscal system, whereas its medial (MGBm) and dorsal (MGBd) divisions belong to the ...

The occipital alpha rhythm (∼10 Hz) is the most prominent electrophysiological activity in the awake human brain [1], yet its functional role [2-4] and relation to visual perception [5] are little understood. Transient stimuli normally elicit a short series of positive and negative deflections lasting between 300 and 500 ms [6-8]: the ...

Processing in one sensory modality may modulate processing in another. Here we investigate how simply viewing the hand can influence the sense of touch. Previous studies showed that non-informative vision of the hand enhances tactile acuity, relative to viewing an object at the same location. However, it remains unclear whether ...

Near-field disturbances in the water column are known to trigger reflex antennular flicking in the crayfish Procambarus clarkii. We have identified the hydrodynamic sensors on the lateral antennular flagellum that constitute an afferent limb of this reflex and have measured the relative directionally dependent thresholds of the sensory neurons associated ...

Sensory-evoked propagating waves are frequently observed in sensory cortex. However, it is largely unknown how an evoked propagating wave affects the activity evoked by subsequent sensory inputs, or how two propagating waves interact when evoked by simultaneous sensory inputs. Using voltage-sensitive dye imaging, we investigated the interactions between two evoked ...

Offset neurons, which fire at the termination of sound, likely encode sound duration and serve to process temporal information. Offset neurons are found in most ascending auditory nuclei; however, the neural mechanisms that evoke offset responses are not well understood. In this study, we examined offset neural responses to tonal ...

BACKGROUNDAND OBJECTIVE: The pattern reversal visual evoked response has been defined as a reproducible cortical response upon stimulation of the eyes. This response depends on the intensity of the light stimulus and its distance from the eyes and is not affected by simultaneous tactile or auditory stimulation. However, in some ...

The contribution of auditory cortex to spatial information processing was explored behaviourally in adult ferrets by reversibly deactivating different cortical areas by subdural placement of a polymer that released the GABA(A) agonist muscimol over a period of weeks. The spatial extent and time course of cortical inactivation were determined electrophysiologically. ...

Fic domains can catalyze the addition of adenosine monophosphate to target proteins. To date, the function of Fic domain proteins in eukaryotic physiology remains unknown. We generated genetic models of the single Drosophila Fic domain-containing protein, Fic. Flies lacking Fic were viable and fertile, but blind. Photoreceptor cells depolarized normally ...

Hypocretin (orexin) deficiency plays a major role in the pathophysiology of narcolepsy-cataplexy. In animal models, hypocretinergic projections to the pedunculopontine nucleus are directly involved in muscle tone regulation mediating muscle atonia - a hallmark of cataplexy. We hypothesized that pedunculopontine nucleus function, tested with prepulse inhibition of the blink reflex, ...

The underlying mechanisms and involved brain areas in sensory gating of repetitive auditory stimuli remain unclear. Especially, the influence of the auditory cortex and the role of temporal precision are under debate. Our first objective was to analyze gating dynamics of local field potentials in the primary auditory cortex and ...

Object Pulsatile arterial compression (AC) of the ventrolateral medulla (VLM) is hypothesized to produce the hypertension in a subset of patients with essential hypertension. In animals, a network of subpial neuronal aggregates in the VLM has been shown to control cardiovascular functions. Although histochemically similar, neurons have been identified in ...

In this issue of Neuron, Chen et al. (2012) and van Versendaal et al. (2012) used fluorescently tagged gephyrin to track inhibitory synapses in the mouse visual cortex in vivo. Their studies show that visual experience-dependent plasticity is associated with clustered and location-specific pruning of inhibitory synapses.