Navigational experience affect cognition: Spatial learning capabilities in captive and wild-born tuco-tucos.

There is a growing recognition of the influence of both genetic and ecological context in shaping different cognitive traits. The hippocampal region is identified as a critical area for memory and learning in mammals, susceptible to modification by environmental influences. Although previous studies have identified the effects of various factors on cognitive parameters during early development, comparatively few research was conducted on wild species to analyze the role of natural environmental stimuli in the formation of spatial learning and memory abilities. Thus, to assess the importance of exposure to a complex and challenging environment during early development, we compared spatial learning performance of captive-born tuco-tucos with previous data obtained in our laboratory from wild-born adult tuco-tucos. The results showed that wild-born individuals learned faster, requiring less time to complete a labyrinth and making fewer errors than those who had no experience in their natural environment. These findings underscore the importance of considering ecological factors in understanding the evolution of brains and cognitive abilities.

Effects of acute maternal stress induced by predator cues on spatial learning and memory of offspring in the subterranean rodent Ctenomys talarum.

One of the main selection pressures to which animals are exposed in nature is predation, which affects a wide variety of biological traits. When the mother experiences this stressor during pregnancy and/or lactation, behavioral and physiological responses may be triggered in the offspring as well. Thus, in order to broaden and deepen knowledge on the transgenerational effects of predation stress, we evaluated how maternal stress experienced during pregnancy and/or lactation affects the spatial abilities of progeny at the onset of adulthood in the subterranean rodent Ctenomys talarum. The results showed that, contrary to what was observed in other rodent species, maternal exposure to predator cues during pregnancy and lactation did not negatively affect the spatial abilities of the offspring, even registering some minor positive effects. Concomitantly, no effects of predatory cues on physiological parameters associated with stress were observed in the progeny. This difference in results between the present study and previous works on maternal stress highlights the importance of considering the species to be evaluated (strain, age and origin-wild or captive-) and the type of stressor used (artificial or natural, intensity of exposure) in the evaluation of the possible transgenerational effects of maternal stress.

Imaging of exercise-induced spinal remodeling in elite rowers.

OBJECTIVES: As in-vivo knowledge of training-induced remodeling of intervertebral discs (IVD) is scarce, this study assessed how lumbar IVDs change as a function of long-term training in elite athletes and age-matched controls using compositional Magnetic Resonance Imaging (MRI). DESIGN: Prospective case-control study. METHODS: Prospectively, lumbar spines of 17 elite rowers (ERs) of the German national rowing team (mean age: 23.9 ±â€¯3.3 years) were imaged on a clinical 3.0 T MRI scanner. ERs were imaged twice during the annual training cycle, i.e., at training intensive preseason preparations (t0) and 6 months later during post-competition recovery (t1). Controls (n = 22, mean age: 26.3 ±â€¯1.9 years) were imaged once at corresponding time points (t0: n = 11; t1: n = 11). Segment-wise, the glycosaminoglycan (GAG) content of lumbar IVDs (n = 195) was determined using glycosaminoglycan chemical exchange saturation transfer (gagCEST). Linear mixed models were set up to assess the influence of cohort and other variables on GAG content. RESULTS: During preseason, IVD GAG values of ERs were significantly higher than those of controls (ERs(t0): 2.58 ±â€¯0.27% (mean ±â€¯standard deviations); controls(t0): 1.43 ±â€¯0.36%; p ≤ 0.001), while during post-competition recovery, such differences were not present anymore (ERs(t1): 2.11 ±â€¯0.18%; controls(t1): 1.89 ±â€¯0.24%; p = 0.362). CONCLUSIONS: Professional elite-level rowing is transiently associated with significantly higher gagCEST values, which indicate increased lumbar IVD-GAG content and strong remodeling effects in response to training. Beyond professional rowing, core-strengthening full-body exercise may help to enhance the resilience of the lumbar spine as a potential therapeutic target in treating back pain.

Human articular cartilage mechanosensitivity is related to histological degeneration - a functional MRI study.

OBJECTIVE: To investigate changes in response to sequential pressure-controlled loading and unloading in human articular cartilage of variable histological degeneration using serial T1ρ mapping. METHOD: We obtained 42 cartilage samples of variable degeneration from the medial femoral condyles of 42 patients undergoing total knee replacement. Samples were placed in a standardized artificial knee joint within an MRI-compatible whole knee-joint compressive loading device and imaged before (δ0), during (δld1, δld2, δld3, δld4, δld5) and after (δrl1, δrl2, δrl3, δrl4, δrl5) pressure-controlled loading to 0.663 ± 0.021 kN (94% body weight) using serial T1ρ mapping (spin-lock multigradient echo sequence; 3.0T MRI system [Achieva, Philips]). Reference assessment included histology (Mankin scoring) and conventional biomechanics (Tangent stiffness). We dichotomized sample into intact (n = 21) and degenerative (n = 21) based on histology and analyzed data using Mann Whitney, Kruskal Wallis, one-way ANOVA tests and Spearman's correlation, respectively. RESULTS: At δ0, we found no significant differences between intact and degenerative samples, while the response-to-loading patterns were distinctly different. In intact samples, T1ρ increases were consistent and non-significant, while in degenerative samples, T1ρ increases were significantly higher (P = 0.004, δ0 vs δld1, δ0 vs δld3), yet undulating and variable. With unloading, T1ρ increases subsided, yet were persistently elevated beyond δ0. CONCLUSION: Cartilage mechanosensitivity is related to histological degeneration and assessable by serial T1ρ mapping. Unloaded, T1ρ characteristics are not significantly different in intact vs degenerative cartilage, while load bearing is organized in intact cartilage and disorganized in degenerative cartilage.

[MRI diagnostics in inflammatory joint and spinal diseases: protocols and special sequences: when and for what?] / MRT-Diagnostik bei entzündlichen Gelenk- und Wirbelsäulenerkrankungen: Protokolle und Spezialsequenzen: Wann und wozu?

Magnetic resonance imaging (MRI) is an important component in rheumatology for imaging diagnostics and therapy monitoring of inflammatory and non-inflammatory diseases of the spine and peripheral joints. The correct selection of suitable and practical MRI protocols and sequences represents a great challenge for physicians with respect to requesting and interpreting the indications for MRI investigations. This review article provides recommendations and suggestions for MRI investigation protocols for clinical utilization and practice. New sequences are evaluated and assessed in order to generate the best possible standardized and comparable examinations for rheumatology in the future and therefore optimize the quality of radiological interventions.

Selective binocular vision loss in two subterranean caviomorph rodents: Spalacopus cyanus and Ctenomys talarum.

To what extent can the mammalian visual system be shaped by visual behavior? Here we analyze the shape of the visual fields, the densities and distribution of cells in the retinal ganglion-cell layer and the organization of the visual projections in two species of facultative non-strictly subterranean rodents, Spalacopus cyanus and Ctenomys talarum, aiming to compare these traits with those of phylogenetically closely related species possessing contrasting diurnal/nocturnal visual habits. S. cyanus shows a definite zone of frontal binocular overlap and a corresponding area centralis, but a highly reduced amount of ipsilateral retinal projections. The situation in C. talarum is more extreme as it lacks of a fronto-ventral area of binocular superposition, has no recognizable area centralis and shows no ipsilateral retinal projections except to the suprachiasmatic nucleus. In both species, the extension of the monocular visual field and of the dorsal region of binocular overlap as well as the whole set of contralateral visual projections, appear well-developed. We conclude that these subterranean rodents exhibit, paradoxically, diurnal instead of nocturnal visual specializations, but at the same time suffer a specific regression of the anatomical substrate for stereopsis. We discuss these findings in light of the visual ecology of subterranean lifestyles.

Facet tropism and facet joint orientation: risk factors for the development of early biochemical alterations of lumbar intervertebral discs.

OBJECTIVE: To assess the glycosaminoglycan (GAG) content of lumbar intervertebral discs (IVD) in healthy volunteers with facet tropism (FT) and sagittal facet joint (FJ) orientation using glycosaminoglycan chemical exchange saturation transfer imaging (gagCEST). METHOD: Seventy-five lumbar IVDs of twenty-five young, healthy volunteers without any history of lumbar spine pathologies (13 female; 12 male; mean age: 28.0 ± 4.4 years; range: 21-35 years) were examined with a 3T MRI scanner. Orientation of FT and FJ were assessed for L3/4, L4/5 and L5/S1 using standard T2 weighted images. Biochemical gagCEST imaging was used to determine the GAG content of each nucleus pulposus (NP) and annulus fibrosus (AF). RESULTS: Significantly higher gagCEST values of NP were found in volunteers without FT and normal FJ orientation compared to volunteers with FT and sagittal FJ orientation >45° (P < 0.0001). GagCEST values were significantly higher in volunteers without FT compared to volunteers with moderate or severe FT (moderate FT: P < 0.0001; severe FT: P = 0.0033). Volunteers with normal FJ orientation showed significantly higher gagCEST values compared to those with sagittal FJ orientation >45° (P < 0.001). We found a significant, negative correlation between gagCEST values and higher angels in sagittal FJ orientation (rho = -0.459; P < 0.0001). CONCLUSION: GagCEST analysis indicated lower GAG values of NP in young volunteers with FT and sagittal orientated FJ, indicating that FT and sagittal orientation of the FJ represent risk factors for the development of early biochemical alterations of lumbar IVDs.

Targeted MRI-guided prostate biopsy: are two biopsy cores per MRI-lesion required?

PURPOSE: This study evaluates the feasibility of performing less than two core biopsies per MRI-lesion when performing targeted MR-guided in-bore prostate biopsy. METHODS: Retrospectively evaluated were 1545 biopsy cores of 774 intraprostatic lesions (two cores per lesion) in 290 patients (66 ± 7.8 years; median PSA 8.2 ng/ml) regarding prostate cancer (PCa) detection, Gleason score, and tumor infiltration of the first (FBC) compared to the second biopsy core (SBC). Biopsies were acquired under in-bore MR-guidance. RESULTS: For the biopsy cores, 491 were PCa positive, 239 of 774 (31 %) were FBC and 252 of 771 (33 %) were SBC (p = 0.4). Patient PCa detection rate based on the FBC vs. SBC were 46 % vs. 48 % (p = 0.6). For clinically significant PCa (Gleason score ≥4 + 3 = 7) the detection rate was 18 % for both, FBC and SBC (p = 0.9). Six hundred and eighty-seven SBC (89 %) showed no histologic difference. On the lesion level, 40 SBC detected PCa with negative FBC (7.5 %). Twenty SBC showed a Gleason upgrade from 3 + 3 = 6 to ≥3 + 4 = 7 (2.6 %) and 4 to ≥4 + 3 = 7 (0.5 %). CONCLUSION: The benefit of a second targeted biopsy core per suspicious MRI-lesion is likely minor, especially regarding PCa detection rate and significant Gleason upgrading. Therefore, a further reduction of biopsy cores is reasonable when performing a targeted MR-guided in-bore prostate biopsy. KEY POINTS: • Higher PI-RADS overall score (IV-V) correlated well with PCa detection rate • In more than 80 % SBC was concordant regarding overall PCa detection • In almost 90 % there was no Gleason upgrading by the SBC • Only 2/54 (3.7 %) csPCa was missed when the SBC was omitted • For IB-GB a further reduction of biopsy cores is reasonable.

Intra-individual assessment of inflammatory severity and cartilage composition of finger joints in rheumatoid arthritis.

OBJECTIVE: To intra-individually assess the association of inflammation severity and cartilage composition measured by RAMRIS synovitis sub-score and delayed gadolinium-enhanced magnetic resonance imaging of the cartilage (dGEMRIC) of metacarpophalangeal (MCP) joints in patients with rheumatoid arthritis (RA). METHODS: Forty-three patients with RA according to ACR/EULAR classification criteria (age 52.9 ± 14.5 years, range, 18-77 years) were included in this study. All study participants received 3-T MRI scans of the metacarpophalangeal joints of the second and third finger (MCP 2 and 3). The severity of synovitis was scored according to the RAMRIS synovitis sub-score by two readers in consensus. In the cases with identical synovitis sub-scores, two radiologists decided in consensus on the joint with more severe synovitis. Cartilage composition was assessed with dGEMRIC. To test the association of inflammation severity and cartilage damage and in order to eliminate inter-patient confounders, each patient's MCP 2 and 3 were dichotomized into the joint with more severe synovitis versus the joint with less severe synovitis for a paired Wilcoxon test of dGEMRIC value. RESULTS: There was a significant difference of dGEMRIC value (median of difference: 47.12, CI [16.6; 62.76]) between the dichotomized MCPs (p = 0.0001). There was a significant correlation between dGEMRIC value and RAMRIS synovitis grading of the joint with more severe synovitis (r = 0.5; p < 0.05) and the joint with less severe synovitis (r = 0.33; p < 0.05). CONCLUSIONS: Our data concur with the concept that synovitis severity is associated with cartilage damage. The local inflammatory status on a joint level correlated significantly with the extent of cartilage degradation in biochemical MRI.

Salinity dependent Na+-K+ATPase activity in gills of the euryhaline crab Chasmagnathus granulata.

The occurrence and response of Na+-K+ATPase specific activity to environmental salinity changes were studied in gill extracts of all of the gills of the euryhaline crab Chasmagnathus granulata from Mar Chiquita coastal lagoon (Buenos Aires Province, Argentina). All of the gills exhibited a salinity dependent Na+-K+ATPase activity, although the pattern of response to environmental salinity was different among gills. As described in other euryhaline crabs highest Na+-K+ATPase specific activity was found in posterior gills (6 to 8), which, with exception of gill 6, increased upon acclimation to reduced salinity. However, a high increase of activity also occurred in anterior gills (1 to 5) in diluted media. Furthermore, both short and long term differential changes of Na+-K+ATPase activity occurred among the gills after the transfer of crabs to reduced salinity. The fact that variations of Na+-K+ATPase activity in the gills were concomitant with the transition from osmoconformity to ionoregulation suggests that this enzyme is a component of the branchial ionoregulatory mechanisms at the biochemical level in this crab.