Diversity, population structure and palaeoecology of the Pleistocene large cervids from the Padang Highlands, Sumatra

This chapter deals with the dentognathic remains of the Late Pleistocene large cervids from the Padang Highlands caves in Sumatra. We used linear and geometric morphometric techniques to investigate variation, taxonomic position and body size trends in a dataset of upper and lower molars. Dental mesowear was used to assess dietary preference in a subsample. The results suggest the Padang Highlands cervids belonged to multiple populations of an early stock of Rusa deer the size of sambar (Rusa unicolor), but morphologically reminiscent of Javan rusa (Rusa timorensis). The Rusa sp. of Sumatra was reconstructed as a mixed feeder with an increase in the grazing component with age

Comparative morphology and postnatal ontogeny of the bony labyrinth in Pantherinae (Felidae, Carnivora) with special emphasis on the lion

The bony labyrinth (inner ear) of mammals reveals systematic as well as morphofunctional information. However, detailed knowledge of bony labyrinth morphology and ontogeny in Pantherinae, that comprise some of the most iconic mammals, is still pending. Hence, we present the first comparative description of the bony labyrinth in all extant species of Panthera and Neofelis some of which are represented by several postnatal stages; particular focus is set on Panthera leo. Our study is based on µCT scans and virtual 3D reconstructions and accompanied by selected morphometric measurements. Even though quite similar in morphology, both genera as well as their species can be distinguished by several features, e.g., shape and relative size of the semicircular canals and presence or absence of an osseous secondary crus commune. In case of the latter, P. pardus shows some intraspecific variation. We also traced the reduction of the fossa subarcuata during ontogeny in P. leo which conforms with previous studies. Negative allometry of the bony labyrinth in relation to skull basal length can be observed during ontogeny as demonstrated by P. leo as well as between different sized species. Although not correlated with the length of the cochlear canal, the number of cochlear turns is higher in captive non-adult P. leo and P. tigris, but lower in adult captive P. pardus. If these intraspecific differences are related to captivity or represent an ontogenetic pattern, needs to be evaluated in future studies based on larger samples

Effects of pre-encoding stress on brain correlates associated with the long-term memory for emotional scenes.

Recent animal and human research indicates that stress around the time of encoding enhances long-term memory for emotionally arousing events but neural evidence remains unclear. In the present study we used the ERP old/new effect to investigate brain dynamics underlying the long-term effects of acute pre-encoding stress on memory for emotional and neutral scenes. Participants were exposed either to the Socially Evaluated Cold Pressure Test (SECPT) or a warm water control procedure before viewing 30 unpleasant, 30 neutral and 30 pleasant pictures. Two weeks after encoding, recognition memory was tested using 90 old and 90 new pictures. Emotional pictures were better recognized than neutral pictures in both groups and related to an enhanced centro-parietal ERP old/new difference (400-800 ms) during recognition, which suggests better recollection. Most interestingly, pre-encoding stress exposure specifically increased the ERP old/new-effect for emotional (unpleasant) pictures, but not for neutral pictures. These enhanced ERP/old new differences for emotional (unpleasant) scenes were particularly pronounced for those participants who reported high levels of stress during the SECPT. The results suggest that acute pre-encoding stress specifically strengthens brain signals of emotional memories, substantiating a facilitating role of stress on memory for emotional scenes

Effects of Transcutaneous Vagus Nerve Stimulation (tVNS) on the P300 and Alpha-Amylase Level: A Pilot Study

Recent research suggests that the P3b may be closely related to the activation of the locus coeruleus-norepinephrine (LC-NE) system. To further study the potential association, we applied a novel technique, the non-invasive transcutaneous vagus nerve stimulation (tVNS), which is speculated to increase noradrenaline levels. Using a within-subject cross-over design, 20 healthy participants received continuous tVNS and sham stimulation on two consecutive days (stimulation counterbalanced across participants) while performing a visual oddball task. During stimulation, oval non-targets (standard), normal-head (easy) and rotated-head (difficult) targets, as well as novel stimuli (scenes) were presented. As an indirect marker of noradrenergic activation we also collected salivary alpha-amylase (sAA) before and after stimulation. Results showed larger P3b amplitudes for target, relative to standard stimuli, irrespective of stimulation condition. Exploratory post hoc analyses, however, revealed that, in comparison to standard stimuli, easy (but not difficult) targets produced larger P3b (but not P3a) amplitudes during active tVNS, compared to sham stimulation. For sAA levels, although main analyses did not show differential effects of stimulation, direct testing revealed that tVNS (but not sham stimulation) increased sAA levels after stimulation. Additionally, larger differences between tVNS and sham stimulation in P3b magnitudes for easy targets were associated with larger increase in sAA levels after tVNS, but not after sham stimulation. Despite preliminary evidence for a modulatory influence of tVNS on the P3b, which may be partly mediated by activation of the noradrenergic system, additional research in this field is clearly warranted. Future studies need to clarify whether tVNS also facilitates other processes, such as learning and memory, and whether tVNS can be used as therapeutic tool

Subjective stress and centro-parietal ERP old/new effect.

<p>A. Experienced stress predicts enhanced centro-parietal ERP old/new difference for emotional pictures (400–800 ms) in the stress group. Correlations between (averaged) subjective stress ratings and centro-parietal ERP old/new effect (400–800 ms) for emotional pictures in both experimental groups (stress vs. controls). B. ERP old/new differences averaged over centroparietal sensors (400–800 ms) for unpleasant, neutral and pleasant pictures in high and low stressed participants and control group. Error bars indicate SEM. C. ERP difference waveforms (old-new) averaged over centroparietal sensors for emotional pictures in high stressed (black line), low stressed (dotted line) and control (grey line) participants. The lower section displays the corresponding scalp topographies of the ERP difference separately for the three groups.</p

Grand average ERPs waveforms at frontal (A) and centro-parietal (B) sensor clusters for old (thick line) and new (dotted line) unpleasant, neutral and pleasant pictures in stressed (black lines) and control (grey lines) participants.

<p>Grand average ERPs waveforms at frontal (A) and centro-parietal (B) sensor clusters for old (thick line) and new (dotted line) unpleasant, neutral and pleasant pictures in stressed (black lines) and control (grey lines) participants.</p

Subjective stress ratings and autonomic measures during and after the SECPT/warm water control condition.

<p>Subjective assessments were measured using a scale from 0 (“not at all”) to 100 (“very much”). Data represent means (SEM). Bold indicates significantly higher values in stress compared to control group (*p<.05, **p<.001).</p

ERPs for correctly classified old and new pictures averaged over centro-parietal sensors (400–800 ms).

<p>Data represent means in µV (SEM).</p