Dendritic plasticity in the adult neocortex.

Dendrites are a major determinant of how neurons integrate and process incoming information, and thus, they play a vital role in the functional properties of neural circuits. During the past 30 years, it has become clear that the functional organization of the adult neocortex (and other parts of the brain) is dynamic and can change in response to experimental manipulations that affect cortical activity patterns. A variety of changes in the cortical microcircuit, including changes in synaptic function, neuronal membrane properties, and axonal trajectories, are associated with these functional changes. In this review, the authors discuss changes in the structure of dendrites in the adult neocortex, the sorts of experimental manipulations that induce these changes, and some possible molecular mechanisms that may underlie the changes.     

Neural basis of implicit motor sequence learning: Modulation of cortical power

Implicit sequence learning describes the acquisition of serially ordered movements and sequentially structured cognitive information, that occurs without awareness. Theta, alpha and beta cortical oscillations are present during implicit motor sequence learning, but their role in this process is unclear. The current study addressed this gap in the literature. A total of 50 healthy adults aged between 19 and 37 years participated in the study. Implicit motor sequence learning was examined using the Serial Reaction Time task where participants unknowingly repeat a sequence of finger movements in response to a visual stimulus. Sequence learning was examined by comparing reaction times and oscillatory power between sequence trials and a set of control trials comprising random stimulus presentations. Electroencephalography was recorded as participants completed the task. Analyses of the behavioral data revealed participants learnt the sequence. Analyses of oscillatory activity, using permutation testing, revealed sequence learning was associated with a decrease in theta band (4–7 Hz) power recorded over frontal and central electrode sites. Sequence learning effects were not observed in the alpha (7–12 Hz) or beta bands (12–20 Hz). Even though alpha and beta power modulations have long been associated with executing a motor response, it seems theta power is a correlate of sequence learning in the manual domain. Theta power modulations on the serial reaction time task may reflect disengagement of attentional resources, either promoting or occurring as a consequence of implicit motor sequence learning     

Narrative language skills of maltreated children living in out-of-home care

Abstract

Purpose: Children’s narrative accounts of their experiences are central to the prosecution of perpetrators of alleged maltreatment. We describe the narrative language skills of children who were placed in out-of-home care (OOHC) following substantiated maltreatment. It was hypothesised that (i) children with such histories would display narrative language skills that fall significantly below published age-expected norms, (ii) narrative language skills and core language skills would be positively correlated and (iii) narrative language skills would be associated with measures of socio-economic disadvantage.

Method: Eighty-three children (40 males and 43 females) aged 5;3 to 12;10 (M?=?7.9, SD = 2.3) from English-speaking home backgrounds were assessed using the Test of Narrative Language and the Clinical Evaluation of Language Fundamentals (CELF-4) Core Language Score. The Raven’s Coloured Progressive Matrices, a measure of nonverbal intelligence, was employed as a covariate.

Result: Forty-two percent of children scored in the below-average range on the Narrative Language Index Ability Index. The same proportion scored at/above age-expected levels on the Narrative Comprehension subtest, and 19% scored at/above age-expected levels on Oral Narration. There was a significant correlation between CELF-4 Core Language Scores and the Narrative Language Index Ability Index. Female carers’ education was significantly positively associated with overall narrative language scores; however, household income and index of socio-economic disadvantage were not significantly associated with narrative language scores.

Conclusion: Children who are victims of substantiated maltreatment should be considered at-risk for compromised ability to provide a narrative account of their experiences. The heterogeneity and often scant oral narrative language skills of these children highlights the importance of police/human services training on best-practice forensic interviewing. Policy and practice implications for speech-language pathology early intervention to support the needs of at-risk children are also discussed.     

Effect of representational borders on responses of supragranular neurons in rat somatosensory cortex

In this paper we study the responses of small populations of neurons in layer II/III near the forepaw/lower jaw border in rat somatosensory cortex, comparing cross border (CB) stimuli to non-cross border stimuli (NCB). We found the excitatory component of the population response to CB stimuli was significantly less than the response to NCB stimuli. Thus, at the representational border there are significant changes in the population response of the horizontal circuitry.     

The use of melanocortin antagonists in cachexia of chronic disease

Cachexia is a wasting syndrome that frequently develops in the setting of chronic diseases including cancer, congestive heart failure, chronic obstructive pulmonary disease, AIDS, renal failure and liver failure. Loss of lean body mass is believed to be a significant factor contributing to morbidity and mortality in these chronic diseases; however, there are currently no treatments available that have proven to be effective in reversing the progressive loss of lean body mass in cachectic patients. Evidence from animal models suggests a compelling link between inflammation, the central melanocortin system and cachexia. This review summarises the current evidence supporting the role of the melanocortin 4 (MC4) receptor subtype in cachexia, and discusses the development and use of small-molecule MC4 antagonists, which have proved to be effective in preventing the loss of lean body mass in animal models of cachexia. MC4 antagonists represent an attractive therapeutic approach for cachexia that may attenuate the loss of lean body mass in cachectic patients.     

Antibody levels and in vitro lymphoproliferative responses to Streptococcus pyogenes erythrogenic toxin A and mitogen of patients with rheumatic fever.

We investigated the in vitro lymphoproliferative responses to a streptococcal mitogen and erythrogenic toxin A of children with acute rheumatic fever (ARF) and patients with chronic rheumatic heart disease (CRHD). Antibody levels to the streptococcal products were also analyzed in the sera of those with ARF or chronic rheumatic heart disease as well as in the sera of children with streptococcal pharyngitis or poststreptococcal glomerulonephritis. Our results demonstrated that the individuals had depressed lymphoproliferative responses during the active stage of rheumatic fever. The depressed responses were not found either to be induced by time-sensitive mitogen-specific suppressor cells or to be related to a dose-response phenomenon. On the other hand, antibody levels to the extracellular mitogens were significantly elevated in the sera of children with ARF compared with the levels in the rest of the groups. The hyperresponsiveness noted among children with ARF was found to be at a quantitative level and was not due to recognition of more epitopes, as determined by Western blotting (immunoblotting). The profile of immune responsiveness in children with ARF to the streptococcal extracellular mitogens is discussed in relation to the pathogenesis of disease.     

Living donor liver resection: A low-tech but highly efficient technique. The Regensburg experience

Background To evaluate a low-tech blunt liver dissecting technique for living-liver-donor procedures. Thirty three adult-to-adult living-donor operations were performed at Regensburg University and Jordan Hospital, Amman. Patients and methods For the technique of parenchymal dissection, dissecting scissors were used for blunt preparation; branches were closed, carefully pressing into the hepatic parenchyma. Donor, surgical procedure data, and data on liver function and recovery were analyzed and compared to literature. Results Median procedure time was 280 min (210 to 420 min). Median blood loss was 350 ml (0 to 650 ml). GOT levels decreased from 260 U/l (140 to 510 U/l) on day 1 to 65 U/l (31 to 220 U/l) on day 7. Bilirubin levels were at 2.0 mmol/l (1.29 to 5.99 mmol/l) on day 1 and 1.26 mmol/l (0.63 to 4.70 mmol/l) on day 7. After 12 days (6 to 23), all donors were discharged. There was no donor mortality. One major complication (biliary leakage) and seven minor complications occurred. Conclusion This technique is a low-tech but efficient donor-dissection technique in living liver transplantation, which is comparable to other well established dissection techniques utilizing technical devices in regards to risk for the donor, performance, and recovery. Aiman Obed and Andreas A. Schnitzbauer contributed equally.