Concept formation as a computational cognitive process.

Hippocampus and entorhinal cortex form cognitive maps that represent relations among memories within a multidimensional space. While these relational maps have long been proposed to contribute to episodic memory, recent work suggests that they also support concept formation by representing relevant features for discriminating among related concepts. Cognitive maps may be refined by medial prefrontal cortex, which selects dimensions to represent based on their behavioral relevance.

Antidepressant Effects of (S)-Ketamine through a Reduction of Hyperpolarization-Activated Current I.

Compelling evidence suggests that a single sub-anesthetic dose of (R,S)-ketamine exerts rapid and robust antidepressant effects. However, the cellular mechanisms underlying the antidepressant effects of (R,S)-ketamine remain unclear. Here, we show that (S)-ketamine reduced dendritic but not somatic hyperpolarization-activated current I of dorsal CA1 neurons in unstressed rats, whereas (S)-ketamine decreased both somatic and dendritic I in chronic unpredictable stress (CUS) rats.

Correction to: Understanding Students' Transition to High School: Demographic Variation and the Role of Supportive Relationships.

The original version of the article was published with few errors in Tables 2 and 4. The correct version of the tables are presented along in this erratum.

Developmental pattern and structural factors of dendritic survival in cerebellar granule cells in vivo.

Granule cells (GCs) in the cerebellar cortex are important for sparse encoding of afferent sensorimotor information. Modeling studies show that GCs can perform their function most effectively when they have four dendrites. Indeed, mature GCs have four short dendrites on average, each terminating in a claw-like ending that receives both excitatory and inhibitory inputs.

Gamma oscillations in cognitive disorders.

Gamma oscillations (∼25-100 Hz) are believed to play a role in cognition. Accordingly, aberrant gamma oscillations have been observed in several cognitive disorders, including Alzheimer's disease and Fragile X syndrome. Here, we review how recent results showing abnormal gamma rhythms in Alzheimer's disease and Fragile X syndrome help reveal links between cellular disturbances and cognitive impairments.

Task-General and Acoustic-Invariant Neural Representation of Speech Categories in the Human Brain.

A significant neural challenge in speech perception includes extracting discrete phonetic categories from continuous and multidimensional signals despite varying task demands and surface-acoustic variability. While neural representations of speech categories have been previously identified in frontal and posterior temporal-parietal regions, the task dependency and dimensional specificity of these neural representations are still unclear. Here, we asked native Mandarin participants to listen to speech syllables carrying 4 distinct lexical tone categories across passive listening, repetition, and categorization tasks while they underwent functional magnetic resonance imaging (fMRI).

Understanding Students' Transition to High School: Demographic Variation and the Role of Supportive Relationships.

The transition to high school is disruptive for many adolescents, yet little is known about the supportive relational processes that might attenuate the challenges students face as they move from middle to high school, particularly for students from more diverse backgrounds. Identifying potential buffers that protect youth across this critical educational transition is important for informing more effective support services for youth. In this study, we investigated how personal characteristics (gender, nativity, parent education level) and changes in support from family, friends, and school influenced changes in socioemotional adjustment and academic outcomes across the transition from middle to high school.

Beta-band activity represents the recent past during episodic encoding.

While much research has focused on understanding how individual stimuli are encoded in episodic memory, less is known about how a series of events is bound into a coherent episode. Cognitive models of episodic memory propose that information about presented stimuli is integrated into a composite representation reflecting one's past experience, allowing events separated in time to become associated. Recent evidence suggests that neural oscillatory activity may be critically involved in this process.

Spatiotemporal dynamics of lesion-induced axonal sprouting and its relation to functional architecture of the cerebellum.

Neurodegenerative lesions induce sprouting of new collaterals from surviving axons, but the extent to which this form of axonal remodelling alters brain functional structure remains unclear. To understand how collateral sprouting proceeds in the adult brain, we imaged post-lesion sprouting of cerebellar climbing fibres (CFs) in mice using in vivo time-lapse microscopy. Here we show that newly sprouted CF collaterals innervate multiple Purkinje cells (PCs) over several months, with most innervations emerging at 3-4 weeks post lesion.

Parental Involvement and Adolescents' Educational Success: The Roles of Prior Achievement and Socioeconomic Status.

Parental educational involvement in primary and secondary school is strongly linked to students' academic success; however; less is known about the long-term effects of parental involvement. In this study, we investigated the associations between four aspects of parents' educational involvement (i.e.

Social and novel contexts modify hippocampal CA2 representations of space.

The hippocampus supports a cognitive map of space and is critical for encoding declarative memory (who, what, when and where). Recent studies have implicated hippocampal subfield CA2 in social and contextual memory but how it does so remains unknown. Here we find that in adult male rats, presentation of a social stimulus (novel or familiar rat) or a novel object induces global remapping of place fields in CA2 with no effect on neuronal firing rate or immediate early gene expression.

Inferential Processing among Adequate and Struggling Adolescent Comprehenders and Relations to Reading Comprehension.

Separate mixed model analyses of variance (ANOVA) were conducted to examine the effect of textual distance on the accuracy and speed of text consistency judgments among adequate and struggling comprehenders across grades 6-12 ( = 1203). Multiple regressions examined whether accuracy in text consistency judgments uniquely accounted for variance in comprehension. Results suggest that there is considerable growth across the middle and high school years, particularly for adequate comprehenders in those text integration processes that maintain local coherence.

Schools, Peers, and Prejudice in Adolescence.

Adolescents' perceptions of the prejudice in their social environments can factor into their developmental outcomes. The degree to which others in the environment perceive such prejudice-regardless of adolescents' own perceptions-also matters by shedding light on the contextual climate in which adolescents spend their daily lives. Drawing on the National Longitudinal Study of Adolescent Health, this study revealed that schoolwide perceptions of peer prejudice, which tap into the interpersonal climate of schools, appeared to be particularly risky for adolescents' academic achievement.

Beta and gamma rhythms go with the flow.

Information flows through visual areas in opposite directions during "bottom-up" intake of current stimuli and "top-down" processes such as attention or memory. In this issue of Neuron, Bastos et al. (2015) report that rhythms of different frequencies coordinate bottom-up and top-down information streams.

Do slow and fast gamma rhythms correspond to distinct functional states in the hippocampal network?

For decades, hippocampal gamma was thought to be a single type of rhythm with a continuously varying frequency. However, an increasing body of evidence supports a new hypothesis regarding hippocampal gamma. The patterns traditionally defined as hippocampal gamma may actually comprise separate gamma subtypes with distinct frequencies and unique functions.

Dendritic translocation of climbing fibers: a new face of old phenomenon.

During postnatal development of the cerebellum, the number of climbing fibers that innervate individual Purkinje cells decreases from many to one. This is one of the most characterized models of activity-dependent refinement of synaptic circuitry in the mammalian brain. As surplus climbing fibers are eliminated, subcellular location of climbing fiber terminals moves from the soma to the dendrites of Purkinje cells.

Theta-gamma coupling in the entorhinal-hippocampal system.

For decades, theta rhythms (∼5-10Hz) have been thought to play a critical role in memory processing in the entorhinal-hippocampal network. However, recent evidence suggests that successful memory performance also requires coupling of ∼30-100Hz gamma rhythms to particular phases of the theta cycle. Recent insights imply ways in which theta-gamma coupling may facilitate transfer of information throughout the entorhinal-hippocampal network.

Demographic marginalization, social integration, and adolescents' educational success.

Links between schools' demographic composition and students' achievement have been a major policy interest for decades. Using a racially/ethnically diverse sample from the National Longitudinal Study of Adolescent Health (N = 6,302; 54% females; 53% White, 21% African American, 15% Latino, 8% Asian American, 2% other race/ethnicity), we examined the associations between demographic marginalization, students' later social integration (loneliness at school, school attachment), and educational performance and attainment. Adolescents who were socioeconomically marginalized at school [i.

Slow and fast γ rhythms coordinate different spatial coding modes in hippocampal place cells.

Previous work has hinted that prospective and retrospective coding modes exist in hippocampus. Prospective coding is believed to reflect memory retrieval processes, whereas retrospective coding is thought to be important for memory encoding. Here, we show in rats that separate prospective and retrospective modes exist in hippocampal subfield CA1 and that slow and fast gamma rhythms differentially coordinate place cells during the two modes.

Harnessing Yarrowia lipolytica lipogenesis to create a platform for lipid and biofuel production.

Economic feasibility of biosynthetic fuel and chemical production hinges upon harnessing metabolism to achieve high titre and yield. Here we report a thorough genotypic and phenotypic optimization of an oleaginous organism to create a strain with significant lipogenesis capability. Specifically, we rewire Yarrowia lipolytica's native metabolism for superior de novo lipogenesis by coupling combinatorial multiplexing of lipogenesis targets with phenotypic induction.

Do men and women show love differently in marriage?

In Western societies, women are considered more adept than men at expressing love in romantic relationships. Although scholars have argued that this view of love gives short shrift to men's ways of showing love (e.g.

Oscillations and hippocampal-prefrontal synchrony.

The hippocampus, a structure required for many types of memory, connects to the medial prefrontal cortex, an area that helps direct neuronal information streams during intentional behaviors. Increasing evidence suggests that oscillations regulate communication between these two regions. Theta rhythms may facilitate hippocampal inputs to the medial prefrontal cortex during mnemonic tasks and may also integrate series of functionally relevant gamma-mediated cell assemblies in the medial prefrontal cortex.

A copper-polyol complex: [Na2(C2H6O2)6][Cu(C2H4O2)2].

The ionic title complex, bis(mu-ethylene glycol)-kappa(3)O,O':O';kappa(3)O:O,O'-bis[(ethylene glycol-kappa(2)O,O')(ethylene glycol-kappaO)sodium] bis(ethylene glycolato-kappa(2)O,O')copper(II), [Na(2)(C(2)H(6)O(2))(6)][Cu(C(2)H(4)O(2))(2)], was obtained from a basic solution of CuCl(2) in ethylene glycol and consists of discrete ions interconnected by O-H...

Separating the effects of age and walking speed on gait variability.

Gait variability has been correlated with fall risk in the elderly. Older adults typically display greater variability than young adults, but the cause of this increase is unclear. Slower walking leads to greater variability in young adults, but slow speeds are also typical in older adults.

Using sandpaper for noninvasive transepidermal optical skin clearing agent delivery.

We present a gentle mechanical method for the noninvasive transepidermal delivery of topically applied optical skin clearing agents. Optical skin clearing reduces light scattering in highly turbid skin with the aid of hyperosmotic chemicals such as glycerol, polyethylene glycol, and solutions of dextrose. Transepidermal delivery of such agents is believed to be most patient compliant and most likely to be used in a clinical environment.