Learning and memory

  • Article
    | Open Access

    Male and female mice need to generate spatial maps that integrate vomeronasal signals of territory owners in the hippocampus-dependent memory. The authors show that vomeronasal information influences learning-related activity in the hippocampus via the amygdaloid PMCo, lateral entorhinal cortex, and dorsal CA1.

    • María Villafranca-Faus
    • , Manuel Esteban Vila-Martín
    •  & Vicent Teruel-Martí
  • Article
    | Open Access

    New instrumental learning occurs through an unexpected delivery of a rewarding stimulus or the withdrawal of a punishing stimulus. The authors show that D1 receptor-expressing medium spiny neurons (MSNs) in the anterior dorsolateral striatum encode newly learned instrumental actions whereas D2 MSNs promote the expression of habitual actions.

    • Alexander C. W. Smith
    • , Sietse Jonkman
    •  & Paul J. Kenny
  • Article
    | Open Access

    When two memories are similar, their encoding and retrieval can be disrupted by each other. Here the authors show that memory interference is resolved through abrupt remapping of activity patterns in the human hippocampal CA3 and dentate gyrus.

    • Guo Wanjia
    • , Serra E. Favila
    •  & Brice A. Kuhl
  • Article
    | Open Access

    Previous work has shown that in rodents phase precession – the phase of action potentials relative to the theta oscillation – is associated with the representation of sequential locations. Here the authors demonstrate that phase precession also occurs in the human hippocampus using single neuron and LFP recordings.

    • Leila Reddy
    • , Matthew W. Self
    •  & Pieter R. Roelfsema
  • Article
    | Open Access

    The relative roles of visual, parietal, and frontal cortex in working memory have been actively debated. Here, the authors show that distraction impacts visual working memory representations in primary visual areas, indicating that these regions play a key role in the maintenance of working memory.

    • Grace E. Hallenbeck
    • , Thomas C. Sprague
    •  & Clayton E. Curtis
  • Article
    | Open Access

    Making a decision requires one to differentiate between choice options, committing to one and leaving the other behind. Here, the authors show that decision-making paradoxically binds options together, such that the outcome of the choice ends up changing the value of both the chosen and the unchosen options, in opposite directions.

    • Natalie Biderman
    •  & Daphna Shohamy
  • Article
    | Open Access

    Scintillators emit visible luminescence when irradiated with X-rays and may enable remote optogenetic control of neurons deep in the brain. The authors inject an inorganic scintillator to activate and inhibit midbrain dopamine neurons in freely moving mice by X-ray irradiation to modulate place preference behavior.

    • Takanori Matsubara
    • , Takayuki Yanagida
    •  & Takayuki Yamashita
  • Article
    | Open Access

    People can search for memories based on their content or context, defined as when and where they were formed. Here, the authors use direct brain recordings to provide evidence in line with the idea that separable neural systems retrieve these two types of information and predict whether recall is organized by time or content.

    • James E. Kragel
    • , Youssef Ezzyat
    •  & Michael J. Kahana
  • Article
    | Open Access

    Intratelencephalic and pyramidal tract neurons are two major types of cortical excitatory neurons that project to cortical and subcortical structures. The authors show that in the prefrontal cortex the two populations have different roles for the maintenance of working memory and for tracking the passage of time.

    • Jung Won Bae
    • , Huijeong Jeong
    •  & Min Whan Jung
  • Article
    | Open Access

    Sleep is known to promote memory consolidation, but the extent to which this is dependent on the memory’s relevance remains unclear. Here, the authors use a brain decoding approach to show that neural representations of rewarded experiences undergo a privileged reactivation during sleep, favouring their consolidation.

    • Virginie Sterpenich
    • , Mojca K. M. van Schie
    •  & Sophie Schwartz
  • Article
    | Open Access

    Cellular activity level at the time of learning is thought to be a critical factor to determine which neurons are recruited to encode memory. Here, the authors show that competitive synaptic plasticity mechanisms influence which neurons will encode a fear memory.

    • Yire Jeong
    • , Hye-Yeon Cho
    •  & Jin-Hee Han
  • Article
    | Open Access

    Hippocampal place cells contribute to navigation and memory formation. Here, the authors use in vivo glutamate imaging to reveal patterns of excitatory input received by place cell dendrites and find more spatially tuned and functionally organized inputs arriving in the place field.

    • Michael D. Adoff
    • , Jason R. Climer
    •  & Daniel A. Dombeck
  • Article
    | Open Access

    Changes in poly-unsaturated free fatty acids (FFAs) have been associated with LTP. Here, using lipidomics analysis the authors characterise FFA changes in the rat brain associated with fear conditioning, and demonstrate that increases in saturated FFAs represent the major change.

    • Tristan P. Wallis
    • , Bharat G. Venkatesh
    •  & Frédéric A. Meunier
  • Article
    | Open Access

    Here the authors compare place cell sequence coding during correct and error trials in a spatial memory task. Sequences coded paths that were longer and more temporally compressed during correct trials and developed a bias to replay paths to a goal location during rest periods of correct but not error trials.

    • Chenguang Zheng
    • , Ernie Hwaun
    •  & Laura Lee Colgin
  • Article
    | Open Access

    To understand how spatial representations emerge and evolve across hippocampal subfields, we compared trial-to-trial dynamics of place cells in CA1 and CA3 in new environments and across days. CA1 place fields form early, shift backwards and partially remap across days whereas in CA3 they develop gradually and are more stable, suggesting distinct functional roles in representing space.

    • Can Dong
    • , Antoine D. Madar
    •  & Mark E. J. Sheffield
  • Article
    | Open Access

    New microgrid recordings on the human hippocampal surface reveal that oscillations travel in reversing directions. The route of travel at a given moment was related to behavior and topographic patterns of activity strength, suggesting directions may be biomarkers of hippocampal cognitive processes.

    • Jonathan K. Kleen
    • , Jason E. Chung
    •  & Edward F. Chang
  • Article
    | Open Access

    Dopamine neurons in the mushroom body help Drosophila learn to approach rewards and avoid punishments. Here, the authors propose a model in which dopaminergic learning signals encode reinforcement prediction errors by utilising feedback reinforcement predictions from mushroom body output neurons.

    • James E. M. Bennett
    • , Andrew Philippides
    •  & Thomas Nowotny
  • Article
    | Open Access

    The Tachykinin 2 (Tac2) pathway in the central amygdala is sufficient and necessary for modulating fear memory consolidation. The authors show that silencing Tac2 neurons in the amygdala of male mice reduces fear expression, while fear expression in female mice is increased when manipulations are made during proestrus.

    • A. Florido
    • , E. R. Velasco
    •  & R. Andero
  • Article
    | Open Access

    How thalamic sensory relays participate in plasticity upon associative fear learning and stable long-term sensory coding remains unknown. The authors show that auditory thalamus neurons exhibit heterogeneous plasticity patterns after learning while population level encoding of auditory stimuli remains stable across days.

    • James Alexander Taylor
    • , Masashi Hasegawa
    •  & Jan Gründemann
  • Article
    | Open Access

    Higher-order sequence learning using a structured graph representation - clone-structured cognitive graphs (CSCG) – can explain how the hippocampus learns cognitive maps. CSCG provides novel explanations for transferable schemas and transitive inference in the hippocampus, and for how place cells, splitter cells, lap-cells and a variety of phenomena emerge from the same set of fundamental principles.

    • Dileep George
    • , Rajeev V. Rikhye
    •  & Miguel Lázaro-Gredilla
  • Article
    | Open Access

    Plastic reweighting of parallel fiber synaptic strength is a mechanism for the acquisition of cerebellum-dependent motor learning. Here, the authors found that optogenetic activation of PCs generates dendritic Ca2+ signals that induce plasticity in vitro and instruct learned changes to coincident eye movements in vivo.

    • Audrey Bonnan
    • , Matthew M. J. Rowan
    •  & Jason M. Christie
  • Article
    | Open Access

    Making sense of the world around us often requires flexible access to information from both semantic and episodic memory systems. Here, the authors show that controlled retrieval from functionally distinct long-term memory stores is supported by shared neural processes in the human brain.

    • Deniz Vatansever
    • , Jonathan Smallwood
    •  & Elizabeth Jefferies
  • Article
    | Open Access

    Epitranscriptomic modifications can regulate learning and memory. Here, the authors provide proteomic and functional analysis of N6-methyladenosine (m6A)-binding proteins in D. melanogaster and unveil behavioral and regulatory defects for m6A/Ythdf mutants.

    • Lijuan Kan
    • , Stanislav Ott
    •  & Eric C. Lai
  • Article
    | Open Access

    Unexpected omission of aversive outcome is encoded as reward via activation of reward-encoding dopaminergic neurons in animals. The authors identify the Drosophila neural circuit through which reward-encoding dopaminergic neurons are activated when an olfactory cue is no longer paired with punishment.

    • Li Yan McCurdy
    • , Preeti Sareen
    •  & Michael N. Nitabach
  • Article
    | Open Access

    Here, the authors show that beta-band coordination between prefrontal and temporal cortex predicts working memory performance. Moreover, inferior temporal neurons exhibits greater memory activity when coordination between these areas is high, suggesting that this interaction supports object memory maintenance.

    • Ehsan Rezayat
    • , Mohammad-Reza A. Dehaqani
    •  & Behrad Noudoost
  • Article
    | Open Access

    Stress-induced glucocorticoids cause mitochondrial damage in neurons, but they are not cleared by mitophagy. Here, the authors show that glucocorticoids inhibit NIX-dependent basal mitophagy, contributing to neurodegeneration in a mouse model that can be reversed by pretreatment with a NIX enhancer.

    • Gee Euhn Choi
    • , Hyun Jik Lee
    •  & Ho Jae Han
  • Article
    | Open Access

    Perineuronal nets may stabilize synaptic connections. Here, the authors show that removal of perineuronal nets disrupts both the temporal and spatial organization of grid cell firing.

    • Ane Charlotte Christensen
    • , Kristian Kinden Lensjø
    •  & Torkel Hafting
  • Article
    | Open Access

    LTP and LTD are involved in shaping hippocampal place field representations. Here, the authors show that de novo pathway-specific hippocampal LTD changes dynamics and stability of newly formed place fields, regulating acquisition and maintenance of novel spatial information in adult rats.

    • Donovan M. Ashby
    • , Stan B. Floresco
    •  & Yu Tian Wang
  • Article
    | Open Access

    Endocannabinoid levels are controlled by the fine balance between their synthesis and degradation. Here, the authors show that memory formation through fear conditioning selectively accelerates the degradation of endocannabinoids in the cerebellum via a lasting increase in GABA release.

    • Christophe J. Dubois
    • , Jessica Fawcett-Patel
    •  & Siqiong June Liu
  • Article
    | Open Access

    Theta and gamma rhythms are essential to ensure timely communication between brain structures during locomotion. Here the authors investigate the association between cerebral blood flow and neural oscillations in freely behaving mice running a linear track.

    • Antoine Bergel
    • , Elodie Tiran
    •  & Ivan Cohen
  • Article
    | Open Access

    Haque et al. demonstrate that the episodic memory of a single visual scene is sufficient for humans to recognize if a visual scene has subsequently changed. A prediction error signal first arises in the visual association cortex when individuals recognize these changes.

    • Rafi U. Haque
    • , Sara K. Inati
    •  & Kareem A. Zaghloul
  • Article
    | Open Access

    The challenge of sensory substitution as a therapeutic approach is to design systems that are well accepted by subjects. Here, in deaf songbirds, the authors substitute hearing with vision, suggesting substitution devices could provide sensory feedback for the key actions that are deprived.

    • Anja T. Zai
    • , Sophie Cavé-Lopez
    •  & Richard H. R. Hahnloser
  • Article
    | Open Access

    When asked to imagine an event such as a party, individuals will vary in their mental imagery based on their specific experience of parties. Here, the authors show that such signatures of personal experience can be read from brain activity elicited as events are imagined.

    • Andrew James Anderson
    • , Kelsey McDermott
    •  & Feng V. Lin
  • Article
    | Open Access

    Acute administration of EPA impairs learning and memory and hippocampal LTP in mice that was mediated through enhancing GABAergic transmission via the 5-HT6R. DHA can prevent EPA-induced impairments at a ratio of EPA to DHA similar to that in marine fish oil via the 5-HT2CR.

    • Ji-Hong Liu
    • , Qian Wang
    •  & Tian-Ming Gao