Biology subjects

van Thriel, C.

Publications and source records attributed to van Thriel, C..

2 recordsLinked to original sources

bioRxiv2026

Odor Annoyance, Sensory Irritation or Relaxation: Acute Effects of Real Pinewood Emissions in Indoor Air Scenarios

Wood is commonly used in the building sector, emitting volatile organic compounds (VOCs) contributing to indoor air quality. These VOC profiles can have a pleasant smell and positive effects e.g., induce relaxation. Contrarily, VOCs can have adverse health effects in higher concentrations. Therefore, some VOCs are regulated by guide values (GV). Potentially positive and negative effects of pinewood emissions, ranging from 0.2 mg/m3 (German GV I for bicyclic terpenes) to 2.0 mg/m3 (GV II) were investigated in an experimental 2 h exposure study using a within-subject design. Thirty-two healthy participants rated the perception, pleasantness, symptoms of irritation, and indicators of well-being. During a demanding working memory task (n-back) and a resting period, heart rate (HR) and HR variability (HRV) changes were measured. Before and after each session physiological markers of sensory irritation were assessed. Ratings indicated that the exposure to GV I and GV II were not perceived as more intense or pleasant. Mostly concentration-independent effects were revealed, indicating that inter-individual factors influenced the ratings rather than the VOCs. The pinewood odors during the n-back task did not cause distraction nor did it facilitate performance as previously suggested. HR/V changes indicated that pinewood odors during and after the n-back tasks did not induce relaxation. Only symptoms of nasal irritation showed some weak concentration-dependency, not supported by physiological markers or comparable ratings of sensory irritation. In conclusion, the fact that no distinct odor is detected suggests that interfering factors potentially prevent the regulation of odors at relevant indoor air concentrations. HighlightsO_LISuccessful exposure to realistic indoor pinewood VOCs C_LIO_LINo effect on ratings of indoor air quality, performance or sensory irritation C_LIO_LINo induction of relaxation during or after stressful tasks C_LIO_LIShort-term exposure to concentrations between GV I and II are non-effective C_LI

physiology↗

bioRxiv2025

An in vivo model for transcranial direct current stimulation of the motor cortex in awake mice.

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique mainly used in humans, in which weak direct currents are applied over the scalp to alter cortical excitability and induce neuroplasticity. Previous studies have demonstrated the value of tDCS for modulating sensory, motor, and cognitive functions, nevertheless, knowledge about how externally applied electric fields affect different components of neuronal networks is still incomplete, and in vivo animal models, which are required for a deeper understanding, are not fully developed. To evaluate the impact of tDCS on cortical excitability, many human experiments assess motor evoked potentials elicited by motor cortex (M1) stimulation. To develop a related in vivo animal model, we recorded electrical activity in M1 of alert mice during and after administration of tDCS over M1. M1 excitability was chronically recorded from layers 2-3, layer 5 and layer 6, evoked by stimulation of the ventral lateral nucleus of the thalamus (VAL). M1-tDCS was applied at 100 and 200 {micro}A for 5 s to test the acute effects on neuronal excitability, and for 15 min to induce after-effects. Acute M1-tDCS increased and decreased the amplitude of VAL-evoked potentials in a polarity-, layer- and intensity-dependent manner. For 15 minutes of anodal or cathodal tDCS, a similar polarity- and intensity-dependent modulation of VAL-evoked potential amplitudes during the 15 minutes of stimulation was observed. After tDCS was switched off, the highest intensity of anodal stimulation induced a significant excitability enhancement during at least two hours after stimulation, whereas the after-effects of cathodal tDCS were less pronounced. The current study demonstrates the feasibility of a mouse model of M1-tDCS to accomplish similar modulatory effects of tDCS on cortical excitability as observed in human experiments. A proper adjustment of tDCS parameters, as compared to application in humans, is however required to obtain these translational effects.

neuroscience↗