Publications by authors named "Anna Magnusson"

Periodontitis and infections with periodontal bacteria have been highlighted as risk factors for dementia. In recent years, attention has been drawn to the role of microglia cells in neurodegenerative diseases. However, there is limited knowledge of the influence of periodontal bacteria on microglia cells.

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Objectives: To study clinical and radiographic outcomes after non-surgical treatment of peri-implantitis using either an oscillating chitosan brush (OCB) or titanium curette (TC) and to observe changes in clinical signs of inflammation after repeated treatment.

Methods: Thirty-nine patients with dental implants (n = 39) presented with radiographic bone level (RBL) of 2-4 mm, bleeding index (BI) ≥ 2, and probing pocket depth (PPD) ≥ 4 mm were randomly assigned to mechanical debridement with OCB (test) or TC (control). Treatment was performed at baseline and repeated at 3, 6, and 9 months in cases with > 1 implant site with BI ≥ 1 and PPD≥4 mm.

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Objectives: This prospective, parallel-group, examiner-blinded, multicentre, randomized, controlled clinical trial aimed to assess the efficacy of an oscillating chitosan brush (OCB) versus titanium curettes (TC) on clinical parameters in the non-surgical treatment of peri-implantitis.

Material And Methods: In five dental specialist clinics, 39 patients with one implant with mild to moderate peri-implantitis, defined as 2-4 mm radiographic reduced bone level, bleeding index (BI) ≥ 2, and probing pocket depth (PPD) ≥ 4 mm were randomly allocated to test and control groups, receiving OCB or TC debridement, respectively. Treatment was performed at baseline and three months.

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The cochlea possesses a robust circadian clock machinery that regulates auditory function. How the cochlear clock is influenced by the circadian system remains unknown. Here, we show that cochlear rhythms are system driven and require local Bmal1 as well as central input from the suprachiasmatic nuclei (SCN).

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Effects of whole-crop barley and grass silages harvested at different maturity stages, with or without protein supplementation, on intake, in vivo digestibility, feces characteristics, and protein utilization in wethers were evaluated. Whole-crop barley silage harvested at heading stage (BH) and at medium milk stage (BM), grass silage (GE) taken at the flag leaf-early heading stage, and grass silage (GL) taken at medium-late heading stage were fed to eight wethers in two 4 × 4 Latin squares. Wethers in one square were fed supplementary rapeseed meal.

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Communication sounds across all mammals consist of multiple frequencies repeated in sequence. The onset and offset of vocalizations are potentially important cues for recognizing distinct units, such as phonemes and syllables, which are needed to perceive meaningful communication. The superior paraolivary nucleus (SPON) in the auditory brainstem has been implicated in the processing of rhythmic sounds.

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Auditory streaming enables perception and interpretation of complex acoustic environments that contain competing sound sources. At early stages of central processing, sounds are segregated into separate streams representing attributes that later merge into acoustic objects. Streaming of temporal cues is critical for perceiving vocal communication, such as human speech, but our understanding of circuits that underlie this process is lacking, particularly at subcortical levels.

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The superior paraolivary nucleus (SPON) is a prominent structure in the mammalian auditory brainstem with a proposed role in encoding transient broadband sounds such as vocalized utterances. Currently, the source of excitatory pathways that project to the SPON and how these inputs contribute to SPON function are poorly understood. To shed light on the nature of these inputs, we measured evoked excitatory postsynaptic currents (EPSCs) in the SPON originating from the intermediate acoustic stria and compared them with the properties of EPSCs in the lateral superior olive (LSO) originating from the ventral acoustic stria during auditory development from postnatal day 5 to 22 in mice.

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The leading treatments for severe hearing disabilities work on the principle of conveying electrical pulses to the auditory brainstem that enable perception of speech. It is currently not known how well the brainstem neurons specialized for decoding such coarse sound information develop when deprived of auditory input activity. Here, we used congenitally deaf α1D mice, lacking activity in the auditory nerve, to investigate the superior paraolivary nucleus (SPON) - a prominent mammalian brainstem structure that responds selectively to sound pulses by rebound spiking.

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The mammalian superior paraolivary nucleus (SPON) is a major source of GABAergic inhibition to neurons in the inferior colliculus (IC), a well-studied midbrain nucleus that is the site of convergence and integration for the majority ascending auditory pathways en route to the cortex. Neurons in the SPON and IC exhibit highly precise responses to temporal sound features, which are important perceptual cues for naturally occurring sounds. To determine how inhibitory input from the SPON contributes to the encoding of temporal information in the IC, a reversible inactivation procedure was conducted to silence SPON neurons, while recording responses to amplitude-modulated tones and silent gaps between tones in the IC.

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The functional role of efferent innervation of the vestibular end-organs in the inner ear remains elusive. This study provides the first physiological characterization of the cholinergic vestibular efferent (VE) neurons in the brainstem by utilizing a transgenic mouse model, expressing eGFP under a choline-acetyltransferase (ChAT)-locus spanning promoter in combination with targeted patch clamp recordings. The intrinsic electrical properties of the eGFP-positive VE neurons were compared to the properties of the lateral olivocochlear (LOC) brainstem neurons, which gives rise to efferent innervation of the cochlea.

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Huntington's disease (HD) is an inherited neurodegenerative disorder caused by a CAG repeat expansion in the huntingtin (HTT) gene. Both central and peripheral innate immune activation have been described as features of the disease. Isolated human HD monocytes have been shown to produce more cytokines upon LPS stimulation compared to control monocytes.

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Article Synopsis
  • The superior paraolivary nucleus (SPON) is crucial for processing sound timing and has neurons that selectively respond to sounds significant for periodicity.
  • Through various recordings, the study found SPON neurons exhibit different spiking patterns (onset, adapting, burst) in response to stimuli, indicating specialized properties for temporal sound encoding.
  • Developmental changes lead to more precise spiking patterns with age, suggesting that these neurons are well-equipped to handle variations in sound and could be essential for understanding communication cues.
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In a single-electrode current-clamp recording, the measured potential includes both the response of the membrane and that of the measuring electrode. The electrode response is traditionally removed using bridge balance, where the response of an ideal resistor representing the electrode is subtracted from the measurement. Because the electrode is not an ideal resistor, this procedure produces capacitive transients in response to fast or discontinuous currents.

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Huntington's disease (HD) is caused by an expanded polyglutamine tract in the protein huntingtin (htt). Although HD has historically been viewed as a brain-specific disease, htt is expressed ubiquitously, and recent studies indicate that mutant htt might cause changes to the immune system that could contribute to pathogenesis. Monocytes from HD patients and mouse models are hyperactive in response to stimulation, and increased levels of inflammatory cytokines and chemokines are found in pre-manifest patients that correlate with pathogenesis.

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How do neurons compute? Two main theories compete: neurons could temporally integrate noisy inputs (rate-based theories) or they could detect coincident input spikes (spike timing-based theories). Correlations at fine timescales have been observed in many areas of the nervous system, but they might have a minor impact. To address this issue, we used a probabilistic approach to quantify the impact of coincidences on neuronal response in the presence of fluctuating synaptic activity.

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The superior paraolivary nucleus (SPON) is a prominent structure in the auditory brainstem. In contrast to the principal superior olivary nuclei with identified roles in processing binaural sound localization cues, the role of the SPON in hearing is not well understood. A combined in vitro and in vivo approach was used to investigate the cellular properties of SPON neurons in the mouse.

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Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by both neurological and systemic abnormalities. Immune activation is a well-established feature of the HD brain and we have previously demonstrated a widespread, progressive innate immune response detectable in plasma throughout the course of HD. In the present work we used multiplex ELISA to quantify levels of chemokines in plasma from controls and subjects at different stages of HD.

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Tones cause vibrations within the hearing organ. Conventionally, these vibrations are thought to reflect the input and therefore end with the stimulus. However, previous recordings of otoacoustic emissions and cochlear microphonic potentials suggest that the organ of Corti does continue to move after the end of a tone.

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Computational modeling is increasingly used to understand the function of neural circuits in systems neuroscience. These studies require models of individual neurons with realistic input-output properties. Recently, it was found that spiking models can accurately predict the precisely timed spike trains produced by cortical neurons in response to somatically injected currents, if properly fitted.

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Hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels are highly expressed in the superior olivary complex, the primary locus for binaural information processing. This hyperpolarization-activated current (I(h)) regulates the excitability of neurons and enhances the temporally precise analysis of the binaural acoustic cues. By using the whole-cell patch-clamp technique, we examined the properties of I(h) current in neurons of the lateral superior olive (LSO) and the medial nucleus of the trapezoid body (MNTB) before and after hearing onset.

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GABA is the main inhibitory neurotransmitter in the mammalian brain, and perturbed GABA signalling is the underlying cause of many neurological and psychiatric disorders. Synaptic release of GABA and the functional consequences of its receptor activation have been studied extensively. However, GABA can also be released in unconventional ways.

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Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by both neurological and systemic abnormalities. We examined the peripheral immune system and found widespread evidence of innate immune activation detectable in plasma throughout the course of HD. Interleukin 6 levels were increased in HD gene carriers with a mean of 16 years before the predicted onset of clinical symptoms.

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Central processing of acoustic cues is critically dependent on the balance between excitation and inhibition. This balance is particularly important for auditory neurons in the lateral superior olive, because these compare excitatory inputs from one ear and inhibitory inputs from the other ear to compute sound source location. By applying GABA(B) receptor antagonists during sound stimulation in vivo, it was revealed that these neurons adjust their binaural sensitivity through GABA(B) receptors.

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The ability to differentiate and give rise to neurons, astrocytes, and oligodendrocytes is an inherent feature of neural stem cells, which raises hopes for cell-based therapies of neurodegenerative diseases. However, there are many hurdles to cross before such regimens can be applied clinically. A considerable challenge is to elucidate the factors that contribute to neural differentiation.

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