Learning and memory

  • Article
    | Open Access

    Autism spectrum disorder is approximately 4.5 times more likely to occur in boys than girls. Here, Werling, Geschwind and Parikshak characterized sexually dimorphic gene expression in the non-diseased, post-mortem, adult and prenatal human brain, and show genes expressed at higher levels in males are significantly enriched for genes upregulated in autistic brain.

    • Donna M. Werling
    • , Neelroop N. Parikshak
    •  & Daniel H. Geschwind
  • Article
    | Open Access

    Rett syndrome is a neurodevelopmental disorder caused by mutations in Mecp2. Here the authors show that Mecp2 loss-of-function leads to upregulation of the NF-κB pathway, and that reducing NF-κB signalling ameliorates phenotypes of Mecp2-null mice, thus offering a potential therapeutic strategy.

    • Noriyuki Kishi
    • , Jessica L. MacDonald
    •  & Jeffrey D. Macklis
  • Article
    | Open Access

    The great tit (Parus major) is known for its complex social-cognitive behaviour. Here, the authors sequence genomes of the great tit and show genes related to learning and cognition in regions under positive selection, as well as neuronal non-CpG methylation patterns similar to those observed in mammals.

    • Veronika N. Laine
    • , Toni I. Gossmann
    •  & Martien A. M. Groenen
  • Article
    | Open Access

    Recent work has implicated hippocampal subfield CA2 in encoding social and contextual memory yet the neural mechanisms are not known. Here, Alexander and colleagues demonstrate that, compared to CA1 neurons, CA2 neurons modify their place fields when presented with social or novel stimuli.

    • Georgia M. Alexander
    • , Shannon Farris
    •  & Serena M. Dudek
  • Article
    | Open Access

    During STDP, the magnitude of postsynaptic Ca2+transients is hypothesized to determine the strength of synaptic plasticity. Here, the authors find that STDP in mature hippocampal synapses does not obey this rule but instead relies on the coordinated activation of NMDARs and VGCCs and their regulation by mGluRs and SK channels.

    • Cezar M. Tigaret
    • , Valeria Olivo
    •  & Jack R. Mellor
  • Article
    | Open Access

    The ventral hippocampus connects to the hypothalamus and has been implicated in feeding behaviours. Here, the authors use a combination of optogenetics and DREADD strategies to dissect the underlying circuit, showing that projections from the vHC to the lateral septum work to regulate feeding suppression.

    • Patrick Sweeney
    •  & Yunlei Yang
  • Article
    | Open Access

    Neuregulin-1 and DISC1 signalling pathways have both been linked to neurodevelopment and schizophrenia. Here, Seshadri et al. demonstrate that DISC1 negatively regulates NRG1-induced ErbB4 signalling in adult cortical interneurons both in vitro and in vivo, possibly via competitive binding to PSD95.

    • Saurav Seshadri
    • , Travis Faust
    •  & Akira Sawa
  • Article
    | Open Access

    Amyloid-beta deposits are a pathological hallmark of Alzheimer’s disease, and have previously been targeted in immunisation therapies. Here, the authors show that oral administration of the small molecule EPPS reduces Aß plaque and oligomer load in APP/PS1 mice and improves learning and memory performance.

    • Hye Yun Kim
    • , Hyunjin Vincent Kim
    •  & YoungSoo Kim
  • Article
    | Open Access

    Whether brief early exposure to a language affects future language processing is unclear. Here Pierce et al.show that brain activity evoked by French pseudowords in monolingual French speaking Chinese adoptees is different from French children with no exposure to Chinese and similar to bilingual Chinese children.

    • Lara J. Pierce
    • , Jen-Kai Chen
    •  & Denise Klein
  • Article
    | Open Access

    The auditory cortex Te2 represents a key node for the assignment of the affective value to sensory stimuli in rodents. Using pharmacogenetic manipulations, this study shows that in Te2 there are neurons which respond to the emotional valence of sounds and their inactivation impairs emotional memories retrieval.

    • Anna Grosso
    • , Marco Cambiaghi
    •  & Benedetto Sacchetti
  • Article
    | Open Access

    Understanding how ß-amyloid contributes to synapse loss and dysfunction is a central goal of Alzheimer’s disease research. Here, Leshchyns’ka et al.identify a novel mechanism by which Aß disassembles hippocampal glutamatergic synapses via cleavage of a neural cell adhesion molecule 2 (NCAM2).

    • Iryna Leshchyns’ka
    • , Heng Tai Liew
    •  & Vladimir Sytnyk
  • Article
    | Open Access

    In vitro differentiation of human pluripotent stem cells (hPSCs) has enabled the generation of neuroectodermal tissues. Here, Sakaguchi et al.use a modified neocortical induction method to generate functional hippocampal granule and pyramidal-like neurons, as well as dorsomedial telencephalic tissues from hPSCs.

    • Hideya Sakaguchi
    • , Taisuke Kadoshima
    •  & Yoshiki Sasai
  • Article
    | Open Access

    Exposure to memory cues during sleep improves subsequent memory recall. Here the authors demonstrate that presenting an additional auditory stimulus during a critical time window following the memory cue abolishes the memory benefit of cueing and its oscillatory correlates during sleep in humans.

    • Thomas Schreiner
    • , Mick Lehmann
    •  & Björn Rasch
  • Article
    | Open Access

    Hippocampal theta oscillations support encoding of spatial information during navigation, yet their role in locomotion is poorly understood. Here the authors demonstrate that hippocampal theta oscillations regulate the speed of locomotion in rodents through a hippocampo-lateral septal-hypothalamic pathway.

    • Franziska Bender
    • , Maria Gorbati
    •  & Alexey Ponomarenko
  • Article
    | Open Access

    The medial temporal lobe (MTL) in the primate brain is known to alter its response when learning new information. Here, Reddy et al.record the activity of single neurons from human subjects, and show that learning a sequence of events can increase MTL neuronal firing rates in anticipation of the upcoming events.

    • Leila Reddy
    • , Marlene Poncet
    •  & Pieter R. Roelfsema
  • Article
    | Open Access

    Adult hippocampal neurogenesis is involved in the response to stress but whether it exerts a positive or negative effect remains unclear. Here the authors ablate hippocampal neurogenesis in mice and find that the effects on anxiety behaviour depend on the time of day, and that neurogenesis specifically impairs the response to stress during the dark cycle.

    • Cheng-Yu Tsai
    • , Ching-Yen Tsai
    •  & Guo-Jen Huang
  • Article
    | Open Access

    Selective biallelic expression of certain genes through genomic imprinting are known to play a role in controlling neurogenesis in the adult mammalian brain. Here the authors investigate the role of imprinting in the dosage control of Igf2 and its relevance for the function of IGF2 as a neurogenic regulator in the mouse brain.

    • S. R. Ferrón
    • , E. J. Radford
    •  & A. C. Ferguson-Smith
  • Article
    | Open Access

    Learning to reinforce rewarding decisions and avoiding repeated mistakes is critical, yet the neural systems mediating feedback processing in value-guided choices remain elusive. Here the authors uncover the spatiotemporal dynamics of two separate but interacting value systems during learning.

    • Elsa Fouragnan
    • , Chris Retzler
    •  & Marios G. Philiastides
  • Article
    | Open Access

    Synaptic plasticity is mediated by the dynamic localization of proteins at synapses, which is partly controlled via palmitoylation of synaptic proteins. Here, the authors show how neuronal activity regulates the palmitoylation reaction through the translocation of the palmitoyl-acyl transferase DHHC5.

    • G. Stefano Brigidi
    • , Brendan Santyr
    •  & Shernaz X. Bamji
  • Article
    | Open Access

    Our memory system maintains flexibility by representing both specific events as well as generalizations across events, yet the brain regions supporting each remain unknown. Here the authors reveal dissociable neural signatures of memory separation and integration in the hippocampus and prefrontal cortex.

    • Margaret L. Schlichting
    • , Jeanette A. Mumford
    •  & Alison R. Preston
  • Article
    | Open Access

    In contrast to predictions from learning theory, humans learn to seek rewards and avoid punishments equally well. Here the authors offer an elegant solution to this problem by demonstrating that humans learn option values relative to a reference point subserved by a common neural substrate.

    • Stefano Palminteri
    • , Mehdi Khamassi
    •  & Giorgio Coricelli
  • Article
    | Open Access

    Recalled memories enter a labile state and are thought to be restabilized through reconsolidation. Here, the authors challenge the long-held notion that reconsolidation is a distinct memory process and demonstrate that the molecular events initiated at recall act instead to constrain premature extinction.

    • Simon Trent
    • , Philip Barnes
    •  & Kerrie L. Thomas
  • Article
    | Open Access

    Sensory cortical tuning is shaped by experience to facilitate coding of features that are predictive of behaviourally relevant outcomes. Here the authors demonstrate that rapid behaviourally driven retuning of human visual cortex involves top–down projections as well as local inhibitory interactions.

    • Lisa M. McTeague
    • , L. Forest Gruss
    •  & Andreas Keil
  • Article
    | Open Access

    Voxel-based morphometry (VBM) involves comparisons of high resolution structural images of the brain between groups, but what causes changes in the VBM signal is unclear. Here the authors perform a VBM study of Thy1-YFP mice following auditory fear conditioning and propose that the signal changes can be partially explained by increases in dendritic spine density.

    • O. P. Keifer Jr
    • , R. C. Hurt
    •  & K. J. Ressler
  • Article
    | Open Access

    The holistic retrieval of complex event memories is thought to be the hallmark of episodic memory. Here, the authors provide behavioural and neuroimaging evidence that the hippocampus binds together the elements forming an event to allow holistic episodic recollection via pattern completion of all elements.

    • Aidan J. Horner
    • , James A. Bisby
    •  & Neil Burgess
  • Article
    | Open Access

    Enhanced glutamatergic transmission in the nucleus accumbens (NAc) has been implicated in the pathophysiology of depression, yet the underlying source is not known. Here, the authors demonstrate a unique role for ventral hippocampal-NAc glutamatergic projections in regulating depression-like behaviour.

    • Rosemary C. Bagot
    • , Eric M. Parise
    •  & Eric J. Nestler
  • Article
    | Open Access

    The brain exhibits a diversity of plasticity mechanisms across different timecales that constitute the putative basis for learning and memory. Here, the authors demonstrate how these different plasticity mechanisms are orchestrated to support the formation of robust and stable neural cell assemblies.

    • Friedemann Zenke
    • , Everton J. Agnes
    •  & Wulfram Gerstner
  • Article
    | Open Access

    Lateral diffusion of receptors between synaptic and extrasynaptic sites is known to mediate plasticity. Hausrat et al. show that diffusion of α5-containing GABAAreceptors is controlled by phosphorylation of the extrasynaptic anchoring protein Radixin, and reveal a role for Radixin in learning and memory.

    • Torben J. Hausrat
    • , Mary Muhia
    •  & Matthias Kneussel
  • Article
    | Open Access

    The ability of animals to respond to life-threatening stimuli is critical for survival, yet the neural circuits mediating innate defensive behaviors are not well understood. Here, the authors reveal a novel collicular–thalamic–amygdala circuit critical for innate defensive responses to visual threats.

    • Pengfei Wei
    • , Nan Liu
    •  & Liping Wang
  • Article
    | Open Access

    Aberrant hippocampal neurogenesis often occurs after acute seizures that produce epilepsy and cognitive impairment but the role of neurogenesis in the development of epilepsy is unclear. Here the authors suppress adult neurogenesis in mice preceding seizures and show that it reduces subsequent chronic seizure frequency and epilepsy-associated cognitive decline.

    • Kyung-Ok Cho
    • , Zane R. Lybrand
    •  & Jenny Hsieh
  • Article
    | Open Access

    Epileptic seizures generate aberrant neurogenesis in the adult mouse hippocampal region but how animals cope with abnormal neurogenesis remains unknown. Here the authors show that microglia are activated through TLR9 signaling and that this leads to sustained expression of TNF-α which attenuates induced aberrant neurogenesis.

    • Taito Matsuda
    • , Naoya Murao
    •  & Kinichi Nakashima
  • Article |

    Several K+ channels control neuronal excitability, but the function of KCNQ5 (Kv7.5), which displays wide expression in the brain, is not known. Here the authors show that KCNQ5 controls excitability and function of hippocampal networks through modulation of synaptic inhibition.

    • Pawel Fidzinski
    • , Tatiana Korotkova
    •  & Thomas J. Jentsch
  • Article
    | Open Access

    Motor learning is characterized by diverse cognitive processes, which lack a unified theoretical framework. Here, Takiyama et al.present a model demonstrating that motor learning is determined by prospective errors, which they test in a specially designed visuomotor adaptation task.

    • Ken Takiyama
    • , Masaya Hirashima
    •  & Daichi Nozaki
  • Article
    | Open Access

    In adults, oscillatory brain activity during sleep is related to memory consolidation. Here, the authors measure brain activity from infants who are exposed to novel word meanings, and show that infant sleep results in the retention and reorganization of recently encoded memories.

    • Manuela Friedrich
    • , Ines Wilhelm
    •  & Angela D. Friederici
  • Article |

    Neurological disorders such as temporal lobe epilepsy (TLE) are known to be regulated by gene networks. In this study, the authors describe a genome-wide approach that uses samples of hippocampal tissue from patients with TLE, to identify the gene Sestrin 3 (SESN3) as a positive regulator of the disease.

    • Michael R. Johnson
    • , Jacques Behmoaras
    •  & Enrico Petretto
  • Article |

    Whether emotional state affects the perception of outcomes, and the possible consequences of this interaction remain unclear. Here the authors use behavioural tests and brain imaging to study the bidirectional interaction between emotional state and learning in humans and find that this interaction may play a role in mood instability.

    • Eran Eldar
    •  & Yael Niv
  • Article
    | Open Access

    Rapidly switching the focus of attention is believed to impair memory, but it is unclear how. Lewis-Peacock and Norman use brain imaging and multivariate analysis to show that when two memories briefly and closely compete in the brain, there is a lasting impairment in the ability to remember these thoughts.

    • Jarrod A. Lewis-Peacock
    •  & Kenneth A. Norman
  • Article |

    The human fusiform face area (FFA) plays a major role in face recognition. Ghuman et al.study the temporal dynamics of face information processing in the FFA and establish the timecourse of information processing as well as the processing stages that FFA contributes to when a face is first viewed.

    • Avniel Singh Ghuman
    • , Nicolas M. Brunet
    •  & R. Mark Richardson
  • Article |

    The mammalian brain is able to rapidly adapt to environmental changes, but it is unclear how this occurs at the level of the single neuron. Hira et al.use two-photon calcium imaging of neurons in the mouse motor cortex after a lever-pull task to demonstrate rapid operant conditioning of single neurons.

    • Riichiro Hira
    • , Fuki Ohkubo
    •  & Masanori Matsuzaki
  • Article |

    Aspects of visual perception learning are known to change with age, but the associated structural correlates are poorly understood. Here the authors show that, surprisingly, visual perception in older individuals involves training-induced structural changes in white matter that are absent in younger individuals.

    • Yuko Yotsumoto
    • , Li-Hung Chang
    •  & Yuka Sasaki
  • Article |

    Conflict monitoring and value learning are often researched as separate processes within psychology, but they share many common neural mechanisms. Here Cavanagh et al.reveal that conflict acts as a cost during value learning, therefore suggesting a general link between conflict monitoring and value learning.

    • James F. Cavanagh
    • , Sean E. Masters
    •  & Michael J. Frank
  • Article
    | Open Access

    MK2/3 kinases are both highly expressed in the hippocampus and cortex of the brain, but their role is unclear. Here Eales et al.show that MK2/3 signalling regulates dendritic spine morphology and is required for synaptic plasticity via the regulation of AMPA receptor trafficking, and cognitive processes.

    • Katherine L. Eales
    • , Oleg Palygin
    •  & Sonia A.L. Corrêa