Until recently, neurons in the healthy brain were considered immune-privileged because they did not appear to express MHC class I (MHCI). However, MHCI mRNA was found be regulated by neural activity developing visual system and has been detected other regions of uninjured brain. Here we show that regulates aspects synaptic function response activity. protein is colocalized postsynaptically with PSD-95 dendrites hippocampal neurons. In vitro , whole-cell recordings from β2m/TAP1 knockout (KO)...

A review of the transient liquid phase (TLP) bonding process is presented in this paper. This concentrates on mechanisms TLP process, including both microstructural development and wettability aspects. However, design related issues engineering applications are also considered. The paper explains how offers potential for producing joints with microstructures hence mechanical properties that similar to those parent materials. isothermal solidification discussed at some length. considers ways...

Tuning curves are widely used to characterize the responses of sensory neurons external stimuli, but there is an ongoing debate as their role in processing. Commonly, it assumed that a neuron's encode stimulus at tuning curve peak, because high firing rates most distinct responses. In contrast, many theoretical and empirical studies have noted nearby stimuli easily discriminated high-slope regions curve. Here, we demonstrate both intuitions correct, relative importance depends on...

We study the properties of a spin-polarized Fermi gas in harmonic trap, using semiclassical (Thomas-Fermi) approximation. Universal forms for spatial and momentum distributions are calculated, results compared with corresponding dilute Bose gas.

Patterned spontaneous activity in the developing retina is necessary to drive synaptic refinement lateral geniculate nucleus (LGN). Using perforated patch recordings from neurons LGN slices during period of eye segregation, we examine how such burst-based can instruct this refinement. Retinogeniculate synapses have a novel learning rule that depends on latencies between pre- and postsynaptic bursts order one second: coincident produce long-lasting enhancement, whereas non-overlapping mild...

The computation represented by a sensory neuron's response to stimuli is constructed from an array of physiological processes both belonging that neuron and inherited its inputs. Although many these are known be nonlinear, linear approximations commonly used describe the stimulus selectivity neurons (i.e., receptive fields). Here we present approach for modeling processing, termed Nonlinear Input Model (NIM), which based on hypothesis dominant nonlinearities imposed mechanisms arise...

Neurons in the medial superior temporal (MST) area of primate visual cortex respond selectively to complex motion patterns defined by expansion, rotation, and deformation. Consequently they are often hypothesized be involved important behavioral functions, such as encoding velocities moving objects surfaces relative observer. However, computations underlying selectivity unknown. In this work we have developed a unique, naturalistic stimulus used it probe MST neurons. The resulting data were...

Abstract Saccadic eye movements play a central role in primate vision. Yet, relatively little is known about their effects on the neural processing of visual inputs. Here we examine this question primary cortex (V1) using receptive-field-based models, combined with an experimental design that leaves retinal stimulus unaffected by saccades. This approach allows us to analyse V1 during saccades unprecedented detail, revealing robust perisaccadic modulation. In particular, produce biphasic...

Organisms process sensory information in the context of their own moving bodies, an idea referred to as embodiment. This is important for developmental neuroscience, robotics and systems neuroscience. The mechanisms supporting embodiment are unknown, but a manifestation could be observation mice brain-wide neuromodulation, including primary visual cortex, driven by task-irrelevant spontaneous body movements. We tested this hypothesis macaque monkeys (Macaca mulatta), primate model human...

Visual neurons can respond with extremely precise temporal patterning to visual stimuli that change on much slower time scales. Here, we investigate how the timing of cat thalamic spike trains-which have as 1 ms-is related stimulus, in context both artificial noise and natural stimuli. Using a nonlinear modeling framework applied extracellular data, demonstrate trains be explained by interplay between an excitatory input delayed suppressive resembles inhibition, such neuronal responses only...

In many forms of retinal degeneration, photoreceptors die but inner circuits remain intact. the rd1 mouse, an established model for blinding diseases, spontaneous activity in coupled network AII amacrine and ON cone bipolar cells leads to rhythmic bursting ganglion cells. Since such could impair and/or cortical responses restored photoreceptor function, understanding its nature is important developing treatments pathologies. Here we analyzed a compartmental wild-type mouse cell predict that...

Abstract Fixation constraints in visual tasks are ubiquitous and cognitive neuroscience. Despite its widespread use, fixation requires trained subjects, is limited by the accuracy of fixational eye movements, ignores role movements shaping input. To overcome these limitations, we developed a suite hardware software tools to study vision during natural behavior untrained subjects. We measured receptive fields tuning properties from multiple cortical areas marmoset monkeys who freely viewed...

The responses of sensory neurons can be quite different to repeated presentations the same stimulus. Here, we demonstrate a direct link between trial-to-trial variability cortical neuron and network activity that is reflected in local field potentials (LFPs). Spikes LFPs were recorded with multielectrode array from middle temporal (MT) area visual cortex macaques during presentation continuous optic flow stimuli. A maximum likelihood-based modeling framework was used predict single-neuron...

Propagating neural activity in the developing mammalian retina is required for normal patterning of retinothalamic connections. This exhibits a complex spatiotemporal pattern initiation, propagation, and termination. Here, we discuss behavior model using combination simulation analytic calculation. Our produces spatially temporally restricted waves without requiring inhibition, consistent with early depolarizing action neurotransmitters retina. We find that highly correlated, regular, occurs...

Neuronal selectivity results from both excitatory and suppressive inputs to a given neuron. Suppressive influences can often significantly modulate neuronal responses impart novel in the context of behaviorally relevant stimuli. In this work, we use naturalistic optic flow stimulus explore neurons middle temporal area (MT) alert macaque monkey; these are interpreted using hierarchical model that incorporates nonlinear properties upstream processing primary visual cortex (V1). context, MT...

The activity of sensory cortical neurons is not only driven by external stimuli but also shaped other sources input to the cortex. Unlike stimuli, these are challenging experimentally control, or even observe, and as a result contribute variability neural responses stimuli. However, such likely “noise” may play an integral role in cortex function. Here we introduce rectified latent variable model (RLVM) order identify using simultaneously recorded neuron populations. RLVM novel that it...

Visual processing depends on specific computations implemented by complex neural circuits. Here, we present a circuit-inspired model of retinal ganglion cell computation, targeted to explain their temporal dynamics and adaptation contrast. To localize the sources such processing, used recordings at levels synaptic input spiking output in vitro mouse retina. We found that an ON-Alpha cell's excitatory inputs were described divisive interaction between excitation delayed suppression, which...

Abstract Feedback in the brain is thought to convey contextual information that underlies our flexibility perform different tasks. Empirical and computational work on visual system suggests this achieved by targeting task-relevant neuronal subpopulations. We combine two tasks, each resulting selective modulation feedback, test whether feedback reflected combination of both selectivities. used feature-discrimination specified at one possible locations uncoupled decision formation from motor...

Although the Shannon mutual information can be used to reveal general features of neural code, it cannot directly address which symbols code are significant. Further insight gained by using measures that specific particular stimuli or responses. The is a previously proposed measure amount associated with response; however, as I show, does not properly characterize stimuli. Instead, propose new measure: stimulus-specific (SSI), defined average responses given presence stimulus. Like other...