The mammalian acoustic startle response (ASR) is a relatively simple motor that can be elicited by sudden and loud stimuli. ASR shows several forms of plasticity, such as habituation, sensitization, prepulse inhibition, thereby making it an interesting model for studying the underlying neuronal mechanisms. Among neurons compose elementary circuit are giant in caudal pontine reticular nucleus (PnC), which may good candidates analyzing basis behavior. In first step this study, we employed...

Abstract Although the connections of auditory brainstem nuclei are well described in adult mammals, almost nothing is known concerning how and when these develop. The purpose present study was to describe development efferent projections cochlear nucleus (CN), first central relay station ascending pathway mammals. We used two tracers rats aged between embryonic day 15 (E15) postnatal 14 (P14; birth rat at E22 = P0). carbocyanine dye DiI applied into CN aldehyde‐fixed tissue. second tracer,...

Among the first postmitotic cells of cerebral cortex is a special population located below cortical plate: subplate neurons. These neurons reach high degree morphological maturity during fetal life, well before layers have matured, yet nearly all these die after birth in cat. Subplate are also known to receive synaptic contacts. Here we investigated whether contacts functional by making intracellular recordings from slices maintained vitro. were identified based on their location and...

The neuron-specific K+-Cl- cotransporter KCC2 extrudes Cl- and renders GABA glycine action hyperpolarizing. Thus, it plays a pivotal role in neuronal inhibition. Development-dependent activation is regulated at the transcriptional level by unknown posttranslational mechanisms. Here, we analyzed protein developing rat lateral superior olive (LSO), prominent auditory brainstem structure. Electrophysiology demonstrated ineffective KCC2-mediated extrusion LSO neurons postnatal day 3 (P3)....

In contrast to our knowledge about the anatomical development of mammalian central auditory system, its physiological properties is still poorly understood. order better understand developing brainstem, we made intracellular recordings in brainstem slices from perinatal rats examine synaptic transmission superior olivary complex, first binaural station ascending pathway. We concentrated on neurons lateral olive (LSO), which adults, are excited ipsilateral side and inhibited contralateral...

Parvalbumin (PV), calretinin (CR), and calbindin (CB) are calcium-binding proteins which presumably involved in the regulation of intracellular calcium concentration. Within rat auditory system, CB is transiently expressed several nuclei during period synapse refinement, indicating a specific function development, yet little known this regard about PV CR. In order to gather more information we analyzed spatiotemporal distribution CR brainstem using immunocytochemistry. adult, was heavily...

Glycine and GABA, the dominant inhibitory neurotransmitters in CNS, assume a depolarizing role early development, leading to increased cytoplasmic Ca2+ levels action potentials. The effect is thought be of some significance for maturation. depolarization caused by Cl- efflux, chloride transporters contribute phenomenon raising intracellular concentration ([Cl-]i) above equilibrium, thereby generating an outward-directed electrochemical gradient Cl-. In mature neurons, [Cl-]i reduced below...

1. The development of excitatory activation in the visual cortex was studied fetal and neonatal cats. During life, immature cerebral (the cortical plate) is sandwiched between two synaptic zones: marginal zone above, an area just below plate, subplate. subplate transient disappears by approximately 2 mo postnatal. Here we have investigated whether plate receive functional inputs fetus, when adultlike pattern input to appears during development. 2. Extracellular field potential recording...

Abstract Immediate éarly genes such as the proto‐oncogene c‐ fos can be expressed in neurons following synaptic excitation by sensory stimulation. C‐ immunocytochemistry has subsequently been shown to a very sensitive marking technique for neuronal activity. Here, antibodies against protein product Fos were used map tonotopic organization auditory system of adult and developing rats. After stimulating rats with pure‐tone pulses, bands Fos‐immunoreactive revealed frequency representation...

Abstract The integration of excitatory and inhibitory synaptic inputs is fundamental to neuronal processing. In the mammalian auditory brainstem, neurons compare from ipsilateral contralateral ear, respectively, for sound localization. However, temporal precision functional roles inhibition in this process are unclear. Here, we demonstrate by vivo recordings lateral superior olive (LSO) that controls spiking with microsecond throughout high frequency click trains. Depending on relative...

1. The inhibitory neurotransmitter glycine can elicit depolarizing responses in immature neurones. We investigated the changes and their ionic mechanism developing neurones of rat lateral superior olive (LSO), an auditory brainstem nucleus involved sound localization. 2. Whole-cell gramicidin perforated-patch recordings were performed from visually identified LSO brain slices was pressure applied for 3-100 ms to soma. Glycine-evoked currents reversibly blocked by strychnine. They mostly...

Within the Ca v 1 family of voltage-gated calcium channels, 1.2 and 1.3 channels are predominant subtypes in brain. Whereas specific functions for each subtype were described adult brain, their role brain development is poorly understood. Here we assess subunits activity-dependent auditory brainstem. We used 1.3-deficient (Ca −/− ) mice because these lack cochlea-driven activity that deprives centers from peripheral input. found a drastically reduced volume all brainstem (range 25–59%, total...

Actin is a regulator of synaptic vesicle mobilization and exocytosis, but little known about the mechanisms that regulate actin at presynaptic terminals. Genetic data on LIMK1, negative actin-depolymerizing proteins ADF/cofilin family, suggest role for in function. However, synapse physiology fully preserved upon genetic ablation ADF mice, n-cofilin mutant mice display defects postsynaptic plasticity, not One explanation this phenomenon overlapping functions physiology. Here, we tested...

Transcription, translation, and turnover of transcripts proteins are essential for cellular function. The contribution those factors to protein levels is under debate, as transcript cognate do not necessarily correlate due regulation translation turnover. Here we propose neuronal polarity a third factor that particularly evident in the CNS, leading considerable distances between somata axon terminals. Consequently, may negatively with CNS regions, i.e., behave reciprocally. To test this...

During electrochemical signal transmission through synapses, triggered by an action potential (AP), a stochastic number of synaptic vesicles (SVs), called the ``quantal content,'' release neurotransmitters in cleft. It is widely accepted that quantal content probability distribution binomial based on ready-release SVs presynaptic terminal. But latter itself fluctuates due to its replenishment, hence actual unknown. We show exact can be derived for general AP inputs steady state. For fixed...

Abstract The reticular formation is composed of heterogeneous cell populations with multiple functions. Among these functions the processing sensory information in context behavior. purpose present study was to identify and characterize neurons rat that receive auditory input. In order do so, we combined intracellular electrophysiology vivo injection horseradish peroxidase, enabling us correlate unequivocally anatomy at single level. We found many caudal pontine nucleus (PnC), which analyzed...

Inhibitory synaptic activity is crucial for many aspects of acoustic information processing and mainly mediated by glycine γ-aminobutyric acid, the two principal inhibitory neurotransmitters in auditory system. Glycine exerts its action via binding to postsynaptic receptors existing various isoforms. Here we have investigated spatiotemporal distribution adult-type, strychnine-sensitive (GlyRs) rat system using a specific antibody against ligand-binding α1 GlyR subunit. In adults, GlyRs were...

The lateral superior olive (LSO), a conspicuous mammalian brainstem nucleus that is involved in sound localization, has become model system for investigating the formation of topographically organized inhibitory and excitatory connections. In experiments employing intracellular injections Lucifer yellow or neurobiotin into lightly fixed brain slices, we have examined soma-dendritic morphology 483 LSO neurons rats between postnatal day (P) 4 P36. A detailed analysis shape complexity dendritic...

Subcellular localization represents an essential, albeit often neglected, aspect of proteome analysis. Generally, the subcellular location proteins determines function cells and tissues. Here we present a robust versatile prefractionation protocol for mammalian tissues which is appropriate minute sample amounts. The yields three fractions: nuclear, cytoplasmic, combined membrane organelle fraction. specificity composition fractions were demonstrated by immunoblot analysis five marker 43...