Neurons of the ventral cochlear nucleus (VCN) perform diverse information processing tasks on incoming activity from auditory nerve. We have investigated cellular basis for functional diversity in VCN cells by characterizing outward membrane conductances acutely isolated using whole-cell, tight-seal, current- and voltage-clamp techniques. The electrical responses fall into two broad categories. Type 1 respond to small depolarizations with a regular train action potentials. Under voltage...

Using kinetic data from three different K + currents in acutely isolated neurons, a single electrical compartment representing the soma of ventral cochlear nucleus (VCN) neuron was created. The include fast transient current ( I A ), slow-inactivating low-threshold LT and noninactivating high-threshold HT ). model also includes fast-inactivating Na current, hyperpolarization-activated cation h 1–50 auditory nerve synapses. With this model, role , play shaping discharge patterns VCN cells is...

1. Convergence of auditory nerve (AN) fibers onto bushy cells the ventral cochlear nucleus (VCN) was investigated with a model that describes electrical membrane properties these cells. The consists single compartment, representing soma, and includes three voltage-sensitive ion channels (fast sodium, delayed-rectifier-like potassium, low-threshold potassium). These have characteristics derived from voltage clamp data VCN also contains leakage channel, capacitance, synaptic inputs. accurately...

Intracellular recordings were made from neurons of the guinea pig dorsal cochlear nucleus in an vitro brain slice preparation. The membrane properties cells studied, and potentials manipulated by current injection to determine how intrinsic conductances might alter cell discharge patterns. Eleven marked with Lucifer yellow. Ten these identified as large pyramidal layer 2 this nucleus, 1 was a "vertical" 3. Two kinds action observed: simple spikes complex spikes. This report discusses only...

Abstract Intracellular recordings from the dorsal cochlear nucleus have identified cells with both simple and complex action potential waveforms. We investigated hypothesis that cartwheel are a specific cell type generates potentials, based on their analogous anatomical, developmental, biochemical similarities to cerebellar Purkinje cells, which known discharge potentials. were made brain slice preparation of guinea pig nucleus. A subpopulation discharged series two or three potentials...

The endbulb of Held synapses between the auditory nerve fibers (ANF) and cochlear nucleus bushy neurons convey fine temporal information embedded in incoming acoustic signal. dynamics synaptic depression recovery is a key regulating transmission at synapse. We studied short-term mature (P22-38) CBA mice with stimulation rates that were comparable to sound-driven activities recorded vivo. Synaptic less severe ( approximately 40% 100 Hz) than reported for immature animals predominately due...

Neuron-glial related cell adhesion molecule (NrCAM) is a regulator of axon growth and repellent guidance, has been implicated in autism spectrum disorders. Here novel postsynaptic role for NrCAM Semaphorin3F (Sema3F)-induced dendritic spine remodeling was identified pyramidal neurons the primary visual cortex (V1). localized to spines star cells postnatal V1, where it coexpressed with Sema3F. deletion mice resulted elevated densities on apical dendrites at both adult stages, electron...

In the ventral cochlear nucleus (VCN), neurons transform information from auditory nerve fibers into a set of parallel ascending pathways, each emphasizing different aspects acoustic environment. Previous studies have shown that VCN differ in their intrinsic electrical properties, including K + currents they express. this study, we examine these more detail using whole cell voltage-clamp techniques on isolated cells adult guinea pigs at 22°C. Our results show differential expression three...

Neurons in the ventral cochlear nucleus (VCN) express three distinct K + currents that differ their voltage and time dependence, inactivation behavior. In present study, we quantitatively analyze voltage-dependent kinetics of these to gain further insight into how they regulate discharge patterns VCN neurons provide supporting data for identification channel components. We find transient A-type current ( I A ) exhibits fourth-order activation a 4 ), inactivates with one or two constants....

Pyramidal cells in the dorsal cochlear nucleus (DCN) show three distinct temporal discharge patterns response to sound: “pauser,” “buildup,” and “chopper.” Similar are seen vitro depend on voltage from which cell is depolarized. It has been proposed that an inactivating A-type K + current ( I KI ) might play a critical role generating different patterns. In this study we examined characteristics of transient currents DCN pyramidal evaluate hypothesis. Morphologically identified rat brain...

Abstract The rate and direction of neurite growth have been shown in a number studies to be determined by the distribution adhesive sites on cone. Recent evidence showing that application extrinsic electric fields can redistribute membrane molecules alter both raised question whether endogenous might produced steady currents cones. To investigate this question, we devised novel circularly vibrating microprobe capable measuring current densities range 5 nA/cm 2 (near theoretical limit...

1. Parallel fibers of the guinea pig dorsal cochlear nucleus (DCN) were electrically stimulated at pial surface in a brain-slice preparation. Extracellular field potentials produced by parallel and postsynaptic cells, response single units identified characterized. Responses compared with those reported for stimulation cerebellum to seen electrical auditory nerve. 2. Stimulation DCN generates consistent set extracellular potentials. In layer 1 DCN, short-latency triphasic wave...

Magnification, the relative size of neural representation a portion visual field, decreases more rapidly with increasing field eccentricity in striate cortex than retinal ganglion cell layer owl monkey ( Aotus trivirgatus ); proportion cells devoted to central vision is much larger comparable cells. Magnification power function magnification layer. A formula for convergence (ganglion cortical neurons) follows from this relationship.

The complexity of modern neurophysiology experiments requires specialized software to coordinate multiple acquisition devices and analyze the collected data. We have developed ACQ4, an open-source platform for performing data analysis in experimental neurophysiology. This integrates tasks acquiring, managing, analyzing ACQ4 has been used primarily standard patch-clamp electrophysiology, laser scanning photostimulation, multiphoton microscopy, intrinsic imaging, calcium imaging. system is...

The acoustic environment contains biologically relevant information on timescales from microseconds to tens of seconds. auditory brainstem nuclei process this temporal through parallel pathways that originate in the cochlear nucleus different classes cells. Although roles ion channels and excitatory synapses processing have been well studied, contribution inhibition is less understood. Here, we show CBA/CaJ mice two major projection neurons ventral nucleus, bushy T-stellate cells, receive...

The cochlear nuclei are the first central processors of auditory information and provide inputs to all major brainstem midbrain nuclei. Although local circuits within understood at a cellular level, spatial patterns connectivity connection strengths in these have been less well characterized. We applied novel, quantitative approach mapping projecting cells mouse anteroventral nucleus (AVCN) using laser-scanning photostimulation glutamate uncaging. amplitude kinetics individual evoked...

Auditory processing in the cerebral cortex is considered to begin with thalamocortical inputs layer 4 (L4) of primary auditory (A1). In this canonical model, A1 L4 initiate a hierarchical cascade, higher-order cortices receiving pre-processed information for slower integration complex sounds. Here, we identify alternative ascending pathways mice that bypass and directly reach multiple layers secondary (A2), indicating parallel activation these areas alongside sequential processing. We found...

Age-related hearing loss (AHL) typically starts from high-frequency regions of the cochlea and over time invades lower-frequency regions. During this progressive loss, sound-evoked activity in spiral ganglion cells is reduced. DBA mice have an early onset AHL. In study, we examined synaptic transmission at endbulb Held synapse between auditory nerve fibers bushy anterior ventral cochlear nucleus (AVCN). Synaptic hearing-impaired areas AVCN was altered old mice. The spontaneous miniature...

Spike timing-dependent plasticity (STDP) has been proposed as a mechanism for optimizing the tuning of neurons to sensory inputs, process that underlies formation receptive field properties and associative memories. The STDP must adjust during development enable optimally tune their selectivity environmental stimuli, but these changes are poorly understood. Here we review how may change in primary cortical layers 2/3 4, initial sites intracortical processing. We provide primer discussing...

Abstract In addition to auditory inputs, dorsal cochlear nucleus (DCN) pyramidal cells in the guinea pig receive and respond somatosensory inputs perform multisensory integration. DCN sounds with characteristic spike‐timing patterns that are partially controlled by rapidly inactivating potassium conductances. Deactivating these conductances can modify both spike rate timing of responses sound. Somatosensory pathways known response rates subsequent acoustic stimuli, but their effect on is...

Layer 4 (L4) of primary auditory cortex (A1) receives a tonotopically organized projection from the medial geniculate nucleus thalamus. However, individual neurons in A1 respond to wider range sound frequencies than would be predicted by their thalamic input, which suggests existence cross-frequency intracortical networks. We used laser scanning photostimulation and uncaging glutamate brain slices mouse characterize spatial organization inputs L4 neurons. Slices were prepared include entire...