Over the last 50 yr, environmental enrichment has been shown to generate more than a dozen changes in brain anatomy. The consequences of these physical on information processing have not well studied. In this study, rats were housed enriched or standard conditions either prior after reaching sexual maturity. Evoked potentials from awake and extracellular recordings anesthetized used document responses auditory cortex neurons. This report details several significant, new findings about...

This study examines the rules governing transfer of spikes between retina and lateral geniculate nucleus (LGN) with goal determining whether most informative retinal preferentially drive LGN responses what role spike timing plays in process. By recording from monosynaptically connected pairs ganglion cells neurons vivo cat, we show that relayed are more likely than nonrelayed to be evoked by stimuli match receptive fields recorded an interspike interval-based mechanism contributes Relayed...

Despite the increasing use of alert animals for studies aimed at understanding visual processing in cerebral cortex, relatively little attention has been focused on quantifying response properties neurons that provide input to cortex. Here, we examine lateral geniculate nucleus (LGN) thalamus macaque monkey and compare these responses those anaesthetized animal. Compared animal, show magnocellular parvocellular animal respond stimuli with significantly higher firing rates. This increase...

Objective: Visual adaptation is a physiological and perceptual process by which the visual system adjusts to changes in environment or stimuli. This fundamental how we perceive world around us allows our efficiently encode information. The retina incorporates adaptaion with its dozens of functionally distinct retinal ganglion cell types. Meanwhile, field prostheses increasing understanding electrical cell-specific stimulation. However, very little known about interaction stimulation on...

Neuronal signals conveying luminance contrast play a key role in nearly all aspects of perception, including depth texture discrimination, and motion perception. Although much is known about the retinal mechanisms responsible for encoding information, relatively little relationship between stimulus processing neuronal visual structures. Here we describe simultaneous recordings from monosynaptically connected ganglion cells lateral geniculate nucleus (LGN) neurons cat to determine how affects...

Retinal signals are transmitted to cortex via neurons in the lateral geniculate nucleus (LGN), where they processed burst or tonic response mode. Burst mode occurs when LGN sufficiently hyperpolarized for T-type Ca²⁺ channels deinactivate, allowing them open depolarization, which can trigger a high-frequency sequence of Na⁺-based spikes (i.e., burst). In contrast, inactivated during and do not contribute spiking. Although is commonly associated with sleep disruption...

Objective. The field of retinal prosthetics has made major progress over the last decade, restoring visual percepts to people suffering from retinitis pigmentosa. stimulation pulses used by present implants are suprathreshold, meaning individual designed activate retina. In this paper we explore subthreshold pulse sequences as an alternate paradigm. Subthreshold have potential address important open problems such fading when patients stimulated at moderate repetition rates and difficulty in...

Temporal features are important for the identification of natural sounds. Earlier studies have shown that cortical processing temporal information can be altered by long-term experience with modulated In a previous study, we observed environmental enrichment dramatically increased response neurons to single tone and noise burst stimuli in both awake anesthetized rats. Here, evaluate how influences auditory cortex. We recorded responses repeated tones bursts rats using epidural evoked...

To further improve the quality of visual percepts elicited by microelectronic retinal prosthetics, substantial efforts have been made to understand how neurons respond electrical stimulation. It is generally assumed that a sufficiently strong stimulus will recruit most neurons. However, recent evidence has shown responses some decrease with excessively stimuli (a non-monotonic response function). Therefore, it necessary identify can be used activate majority even when such cells are part...

The rat auditory cortex is divided anatomically into several areas, but little known about the functional differences in information processing between these areas. To determine filter properties of posterior field (PAF) neurons, we compared neurophysiological responses to simple tones, frequency modulated (FM) sweeps, and amplitude noise tones with primary (A1) neurons. PAF neurons have excitatory receptive fields that are on average 65% broader than A1 result narrow broadband inputs...

Over the past two decades retinal prostheses have made major strides in restoring functional vision to patients blinded by diseases such as retinitis pigmentosa. Presently, implants use single pulses activate retina. Though this stimulation paradigm has proved beneficial patients, an unresolved problem is inability selectively stimulate on and off visual pathways. To end our goal was test, using white noise, voltage-controlled, cathodic, monophasic pulse stimulation, whether different...

Visual processing depends on sensitive and balanced synaptic neurotransmission. Extracellular matrix proteins in the environment of cells are key modulators synaptogenesis plasticity. In present study, we provide evidence that combined loss four extracellular components, brevican, neurocan, tenascin-C, tenascin-R, quadruple knockout mice leads to severe retinal dysfunction diminished visual motion

Burst activity is a ubiquitous feature of thalamic neurons and well documented for visual in the lateral geniculate nucleus (LGN). Although bursts are often associated with states drowsiness, they also known to convey information cortex particularly effective evoking cortical responses. The occurrence depends on (1) inactivation gate T-type Ca2+ channels (T-channels), which become de-inactivated following periods increased membrane hyperpolarization, (2) opening T-channel activation gate,...

The interspike interval (ISI) preceding a retinal spike has strong influence on whether spikes will drive postsynaptic responses in the lateral geniculate nucleus (LGN). This ISI-based filtering of could, principle, be used as mechanism for processing visual information en route from retina to cortex; however, this form not been previously explored. Using white noise stimulus and reverse correlation analysis, we compared receptive fields associated with over range ISIs (0-120 ms). Results...

Loss of function mutations the chorein-encoding gene VPS13A lead to chorea-acanthocytosis (ChAc), a neurodegenerative disorder with accelerated suicidal neuronal cell death, which could be reversed by lithium. Chorein upregulates serum and glucocorticoid inducible kinase SGK1. Targets SGK1 include Na+/K+-ATPase, pump required for survival. To explore whether chorein-deficiency affects Na+/K+ capacity, cortical neurons were differentiated from iPSCs generated fibroblasts ChAc patients healthy...

Bionic vision systems are currently limited by indiscriminate activation of all retinal ganglion cells (RGCs) -despite the dozens known RGC types which each encode a different visual message.Here, we use spike-triggered averaging to explore how electrical responsiveness varies across toward goal using this variation create type-selective stimuli.A battery stimuli and randomly distributed sequence pulses were delivered healthy degenerating (4-week-old rd10) mouse retinas.Ganglion cell spike...

Visual information processed in the retina is transmitted to primary visual cortex via relay cells lateral geniculate nucleus (LGN) of dorsal thalamus. Although retinal ganglion are source driving input LGN neurons, not all spikes cortex. Here, we investigate relationship between stimulus contrast and retinogeniculate communication test hypothesis that both time course strength interactions dynamic dependent on contrast. By simultaneously recording spiking activity synaptically connected...

Cortical responses are adjusted and optimized throughout life to meet changing behavioral demands compensate for peripheral damage. The cholinergic nucleus basalis (NB) gates cortical plasticity focuses learning on behaviorally meaningful stimuli. By systematically varying the acoustic parameters of sound paired with NB activation, we have previously shown that tone frequency amplitude modulation rate alter topography selectivity tuning in primary auditory cortex. This result suggests...

Studies investigating neural information processing often implicitly ask both, which strategy out of several alternatives is used and how this implemented in dynamics. A prime example are studies on predictive coding. These whether confirmed predictions about inputs or prediction errors between internal passed a hierarchical system—while at the same time looking for correlates coding predictions. If we do not know exactly what system predicts any given moment, results circular analysis—as...