Investigating the Etiology and Diagnosis of Sacroiliac Joint Pain

The sacroiliac (SI) joint is often characterized as a large, auricular-shaped, and diarthrodial synovial joint. The SI ligamentous structure is more extensive in the dorsal part due to the absence of the posterior capsule, which functions as a connecting band between the sacrum and ilium. In addition, a network of muscles supports the SI joint that helps deliver regional muscular forces to the pelvic bones. The third and fourth decades of life promote senescent changes manifested by surface irregularities, crevice formation, fibrillation, and clumping of chondrocytes.

Single caudate neurons encode temporally discounted value for formulating motivation for action

The term ‘temporal discounting’ describes both choice preferences and motivation for delayed rewards. Here we show that neuronal activity in the dorsal part of the primate caudate head (dCDh) signals the temporally discounted value needed to compute the motivation for delayed rewards. Macaque monkeys performed an instrumental task, in which visual cues indicated the forthcoming size and delay duration before reward. Single dCDh neurons represented the temporally discounted value without reflecting changes in the animal’s physiological state. Bilateral pharmacological or chemogenetic inactivation of dCDh markedly distorted the normal task performance based on the integration of reward size and delay, but did not affect the task performance for different reward sizes without delay. These results suggest that dCDh is involved in encoding the integrated multidimensional information critical for motivation.

Shell-breaking predation on gastropods by Badister pictus (Coleoptera, Carabidae) with strikingly asymmetric mandibles

The adults and larvae of some groups in the coleopteran family Carabidae are known to prey on snails (Mollusca: Gastropoda). Most species of the carabid tribe Licinini are believed to feed on live snails. However, the snail-eating behavior of only a few species has been studied. Whether adults of the licinine genus Badister can prey on live snails was tested by providing 155 live snails of 20 species (eleven terrestrial and nine aquatic species) to adults of Badister pictus Bates, 1873, and observing their behavior under laboratory conditions. Six of the 20 snail species have an operculum that can close the aperture of the shell. Each B. pictus adult attacked all of the snails provided. Badister pictus successfully preyed on ten terrestrial and six aquatic snail species. These beetles used their strikingly asymmetrical mandibles to break the dextral shells along the dorsal part of the whorls from the outer lip of the aperture towards the apex, allowing subsequent consumption of the soft bodies. However, 41.9% of snails could not be eaten by B. pictus adults. The rate of predation success by B. pictus decreased with increasing shell size and thickness of snails. In addition, the presence of an operculum decreased the rate of predation success by B. pictus. The results show that the shell size, thickness, and operculum of some snail species could play important roles in preventing B. pictus mandibles from breaking the shells. Therefore, Badister beetles may exert selective pressure on the evolution of defensive shell structures in small-sized snails.

Blind Visualization of Task-Related Networks From Visual Oddball Simultaneous EEG-fMRI Data: Spectral or Spatiospectral Model?

Various disease conditions can alter EEG event-related responses and fMRI-BOLD signals. We hypothesized that event-related responses and their clinical alterations are imprinted in the EEG spectral domain as event-related (spatio)spectral patterns (ERSPat). We tested four EEG-fMRI fusion models utilizing EEG power spectra fluctuations (i.e., absolute spectral model - ASM; relative spectral model - RSM; absolute spatiospectral model - ASSM; and relative spatiospectral model - RSSM) for fully automated and blind visualization of task-related neural networks. Two (spatio)spectral patterns (high δ4 band and low β1 band) demonstrated significant negative linear relationship (pFWE < 0.05) to the frequent stimulus and three patterns (two low δ2 and δ3 bands, and narrow θ1 band) demonstrated significant positive relationship (p < 0.05) to the target stimulus. These patterns were identified as ERSPats. EEG-fMRI F-map of each δ4 model showed strong engagement of insula, cuneus, precuneus, basal ganglia, sensory-motor, motor and dorsal part of fronto-parietal control (FPCN) networks with fast HRF peak and noticeable trough. ASM and RSSM emphasized spatial statistics, and the relative power amplified the relationship to the frequent stimulus. For the δ4 model, we detected a reduced HRF peak amplitude and a magnified HRF trough amplitude in the frontal part of the FPCN, default mode network (DMN) and in the frontal white matter. The frequent-related β1 patterns visualized less significant and distinct suprathreshold spatial associations. Each θ1 model showed strong involvement of lateralized left-sided sensory-motor and motor networks with simultaneous basal ganglia co-activations and reduced HRF peak and amplified HRF trough in the frontal part of the FPCN and DMN. The ASM θ1 model preserved target-related EEG-fMRI associations in the dorsal part of the FPCN. For δ4, β1, and θ1 bands, all models provided high local F-statistics in expected regions. The most robust EEG-fMRI associations were observed for ASM and RSSM.

‘Nemacheilus’ argyrogaster, a new species of loach from southern Laos (Teleostei: Nemacheilidae)

‘Nemacheilus’ argyrogaster, new species, is described from the Xe Kong, Mekong drainage, in Attapeu and Xe Kong provinces, southern Laos. It is distinguished from all other Nemacheilidae in Southeast Asia by its unique colour pattern made of a bold black midlateral stripe separating the yellowish brown dorsal part of the body from the silvery whitish ventral part and a middorsal row of 14–19 thin saddles. Besides, the male has a globulous suborbital flap with tubercles along its free, posterior edge, and the pectoral fin with thickened anterior ray and branched rays 1–4 and unculiferous pads behind them covered by small tubercles; lips thin, lower lip continuous with a narrow median notch. It was found in moderate to fast flowing water, over pebble to stone bottom. ‘Nemacheilus’ argyrogaster, was earlier misidentified as N. longistriatus; it is provisionally placed in the genus Nemacheilus.

Rapid active-reflection display on dorsal stripes of Atherinomorus lacunosus

A large number of living creatures are able to use environmental light effectively as a biological display. The biological structural colors are very attractive not only within the coloring species but also to humans. However, the detailed function of bio-reflectors, which constitute the structural color with respect to communication, remains unknown. Atherinomorus lacunosus has alignments of iridophore spots on its dorsal part. Here it is found that a spot with a diameter of approximately 0.1 mm causes a rhythmic blinking of light owing to rapid reflection changes in iridophores existing inside the spot. The iridophores contain reflecting particles which show similar rotational responses to magnetic field under a light exposure. The speed of the intensity change of light at a frequency of approximately 1 Hz is proposed to be controlled by the nervous system of A. lacunosus. This kind of passive illumination may contribute to the development of a new optical device with low energy consumption.

Severe hypersomnia after unilateral infarction in the pulvinar nucleus– a case report

Background Although a central role of the thalamus for sleep regulation is undisputed, the exact localization of the crucial structures within the thalamus remains controversial. Case presentation Here we report a 35 year old woman with no prior comorbidities who developed severe and persistent hypersomnia with long sleep time after a small right-sided MRI-verified thalamic stroke affecting the dorsal part of the pulvinar and the dorsolateral boarders of the dorsomedial nuclei. Conclusion The observed symptoms suggest a crucial role of posterior thalamus but not the midline parts of the thalamus in sleep-wake control.