Attorney demands for protected psychological test information: Is access necessary for cross examination or does it lead to misinformation? An interorganizational* position paper.

Objective: Some attorneys claim that to adequately cross examine neuropsychological experts, they require direct access to protected test information, rather than having test data analyzed by retained neuropsychological experts. The objective of this paper is to critically examine whether direct access to protected test materials by attorneys is indeed necessary, appropriate, and useful to the trier-of-fact. Method: Examples are provided of the types of nonscientific misinformation that occur when attorneys, who lack adequate training in testing, attempt to independently interpret neurocognitive/psychological test data. Results: Release of protected test information to attorneys introduces inaccurate information to the trier of fact, and jeopardizes future use of tests because non-psychologists are not ethically bound to protect test content. Conclusion: The public policy underlying the right of attorneys to seek possibly relevant documents should not outweigh the damage to tests and resultant misinformation that arise when protected test information is released directly to attorneys. The solution recommended by neuropsychological/psychological organizations and test publishers is to have protected psychological test information exchanged directly and only between clinical psychologist/neuropsychologist experts.

Hippocampal replays appear after a single experience and incorporate greater detail with more experience.

The hippocampus is implicated in memory formation, and neurons in the hippocampus take part in replay sequences that have been proposed to reflect memory of explored space. By recording from large ensembles of hippocampal neurons as rats explored various tracks, we show that sustained replay appears after a single experience. Further, we found that with repeated experience in a novel environment, replay slows down, taking more time to traverse the same trajectory. This effect was dependent on experience, not passage of time, and was environment specific. By investigating the slow-gamma (25-50 Hz) hover-and-jump dynamics within replays, we show that replay slows by adding more hover locations, increasing the resolution of the behavioral trajectory. We provide evidence that inhibition and cortical engagement both increase as replay slows. Thus, replays can reflect single experiences and evolve with re-exposure, in a manner consistent with the encoding of greater detail into replay memories with experience.

Acute idiopathic pulmonary hemorrhage in infants. Report of two cases and literature review / Hemorragia pulmonar idiopática aguda en pediatría: reporte de 2 casos y revisión en la literatura

Acute idiopathic pulmonary hemorrhage is a rare life-threatening disease in children. The classic triad includes hemoptysis, anemia and respiratory distress. Since clinical presentation may vary, diagnosis can be difficult. Severe respiratory distress, and ventilatory failure requiring mechanical ventilation are often present. Chest X-rays usually show unilateral or bilateral infiltrates, therefore, other causes of pulmonary hemorrhage must be excluded, since most of them correspond to systemic diseases. Treatment often requires intravenous steroids to solve the respiratory failure in most cases. We present two cases involving infants treated at Hospital San José (a fourth level hospital in Bogotá, Colombia) with acute idiopathic pulmonary hemorrhage which required mechanical ventilation and responded to intravenous steroids. A literature review was conducted with special emphasis on clinical presentation, diagnosis and therapeutic approaches.

La hemorragia pulmonar idiopática aguda es una enfermedad poco común en pediatría que amenaza la vida de lactantes. La tríada clásica se caracteriza por hemoptisis, anemia y dificultad respiratoria, aunque su presentación clínica es variable, por lo que su diagnóstico presenta dificultades. Este cuadro de clínico se presenta junto a dificultad respiratoria severa y falla ventilatoria, que requiere una ventilación mecánica. En la radiografía se visualizan infiltrados unilaterales y/o bilaterales, por lo que deben excluirse otras causas de hemorragia pulmonar que en su mayoría son enfermedades sistémicas. El tratamiento requiere esteroides endovenosos que permitan resolver la falla respiratoria en la mayoría de los casos. Se presentan dos casos de lactantes menores atendidos en el Hospital de San José (hospital de cuarto nivel en Bogotá D.C.), con un cuadro agudo de hemorragia pulmonar idiopática con ventilación mecánica y que responden al tratamiento con esteroides endovenosos. Se realiza revisión de la literatura haciendo particular énfasis en la presentación clínica, el enfoque diagnóstico y terapéutico

Trajectory events across hippocampal place cells require previous experience.

Replay of hippocampal place cell sequences has been proposed as a fundamental mechanism of learning and memory. However, the standard interpretation of replay has been challenged by reports that similar activity is observed before experience ('preplay'). By the preplay account, pre-existing temporal sequences are mapped onto new experiences without learning sequential structure. Here we employed high density recording methods to monitor hundreds of place cells simultaneously while rats explored multiple novel environments. While we observed large numbers of synchronous spiking events before experience, they were not temporally correlated with subsequent experience. Multiple measures differentiated pre-experience and postexperience events that, taken together, defined the latter but not the former as trajectory-depicting. The formation of events with these properties was prevented by administration of an NMDA-receptor antagonist during experience. These results suggest that the sequential structure of behavioral episodes is encoded during experience and reexpressed as trajectory events.

Dissociation between the experience-dependent development of hippocampal theta sequences and single-trial phase precession.

Theta sequences are circuit-level activity patterns produced when groups of hippocampal place cells fire in sequences that reflect a compressed behavioral order of place fields within each theta cycle. The high temporal coordination between place cells exhibited in theta sequences is compatible with the induction of synaptic plasticity and has been proposed as one of the mechanisms underlying the encoding of episodic memory of recently acquired experience. Yet how theta sequences develop with experience has not been directly addressed. Here we simultaneously recorded large numbers of cells in the dorsal hippocampal CA1 area from rats exploring on a novel linear track. Although place cell firing activities accurately represented the animal's current location, distinct theta sequences were absent on the first lap but emerged immediately thereafter and remained stable once established. The absence of theta sequences on the first lap was not due to place field instability, decreased overall excitability of place cells, behavior variables, or the absence of individual neuronal phase precession. We observed strong single-lap phase precession in a significant percentage of place fields on the first lap and throughout the recording. Individual neuronal phase precession was stable from the first lap to subsequent laps but, across neurons, phase precession became more synchronized after experience, suggesting a novel mechanism for the generation of theta sequences. These results suggest that experience-independent temporal coding in individual neurons is combined with rapid plasticity of hippocampal neural networks during experience to acquire predictive representations of the immediate future.

Decreased motoneuron survival in Igf2 null mice after sciatic nerve transection.

The search for therapeutic targets to prevent neurons from dying is ongoing and involves the exploration of a long list of neurotrophic factors. Insulin-like growth factor 2 (IGF2) is a member of the insulin family with known neurotrophic properties. In this study, we used Igf2 knockout (Igf2) neonate mice to determine whether Igf2 deficiency is detrimental to motor neuron survival after axonal injury. Results show that Igf2 neonatal mice are more susceptible to motor neuron damage than Igf2 mice, as they have a significantly lower percentage of motor neuron survival after a sciatic nerve transection. Neuronal survival was significantly improved in Igf2 mice when IGF2 was administered. These results support the role of IGF2 in neonatal motor neuron survival.

Igf2 deficiency results in delayed lung development at the end of gestation.

IGF-II is a polypeptide hormone with structural homology to insulin and IGF-I. IGF-II plays an important role in fetal growth as mice with targeted disruption of the IGF-II gene (Igf2) exhibit severe growth retardation. The role of IGFs in the fetal lung has been suggested by several studies, including those that have identified IGF mRNA expression, and that of their receptors and binding proteins in the lungs at different stages of development. In this study, we used mice carrying a null mutation of Igf2 (Igf2-/- mice) to determine whether the absence of IGF-II had any effect in fetal lung maturation. Our results showed that the lungs of Igf2-/- fetuses had thicker alveolar septae and poorly organized alveoli when compared with those of Igf2+/+ on d 17.5 and 18.5 of gestation. These morphological alterations may be the result of exposure to lower levels of glucocorticoids because plasma corticosterone levels were significantly lower in Igf2-/- mothers compared with wild-type controls. In support of this, fetuses from homozygous knockout matings, where mothers were treated with 15 microg/ml corticosterone, and Igf2-/- fetuses obtained from heterozygous matings had similar lung histology to those of wild-type fetuses. Finally, we found that IGF-I and SP-B mRNA levels were up-regulated in the lungs of Igf2-/- fetuses at the end of gestation. This study suggests that Igf2 plays an important role in the development of the fetal lung and may affect fetal lung maturation by regulating maternal factors, such as corticosterone levels, during pregnancy.