Research articles

Emotional arousal is known to produce long-lasting memories for emotional experiences. Here the authors find that brain states associated with emotional arousal can persist tens of minutes later, biasing and enhancing how new, unrelated information is encoded into memory and later remembered.

The authors show that, unlike the consolidation and refinement of excitatory connections observed during sensory map formation, a dramatic broadening of patterned activation domains, connectivity, and tuning occurs in interneurons in the olfactory bulb. This developmental expansion is sensitive to activity manipulations and may reveal general principles of interneuron network development.

The authors show that pregnancy involves substantial and consistent structural changes in the human brain, primarily located in regions subserving social cognition. These changes overlap with areas that respond to the mothers' babies and predict measures of postpartum maternal attachment. Moreover, they endure for at least 2 years after pregnancy.

The hypothalamus is a brain region rich in functionally segregated neurons. Here Romanov and colleagues use single-cell RNA sequencing to distinguish 62 neuronal subtypes and define their neuropeptide and neurotransmitter makeup. They then show that onecut-3-containing dopamine neurons populate the periventricular area and are wired into the circadian circuitry.

Using an environment composed of interconnected paths, the authors demonstrate that subiculum encodes a previously unrecognized form of spatial information, the axis of travel. This discovery has implications for how path positions and orientations can be related to the larger environment.

Body fluid conditions are continuously monitored in the brain in order to regulate thirst and salt appetites. Through a combination of optogenetics and electrophysiology, the authors reveal distinct neural mechanisms in the subfornical organ for generating appropriate water- and salt-intake behaviors according to body fluid conditions.

The authors report on a subpopulation of neurons in retrosplenial cortex that is more sensitive to head direction in a local, visually defined reference frame than to global head direction. These neurons may be the means by which visual landmark information can influence the overall sense of direction.

The authors developed small-molecule inhibitors of STOML3 oligomerization, a membrane protein that interacts with mechanosensitive ion channels, such as Piezo2. One of these molecules was effective in silencing touch receptors and reversed touch-evoked pain associated with nerve injury or diabetic neuropathy.

How the hippocampus and sensory cortical regions interact during memory consolidation is largely unknown. The authors identify a rapid loop of information flow from auditory cortex to the hippocampus and back, around the times of hippocampal sharp wave ripples, which coordinates memory reactivation during sleep across these brain areas.

Cognitive tasks require storing and manipulating information for short periods of time. Verbal working memory involves storing and manipulating speech information, but the underlying brain mechanisms remain unknown. The authors identify storage systems for sensory and motor representations and two distinct manipulation systems, demonstrating that multiple subsystems comprise verbal working memory.

Activation of putative aldosterone-sensitive neurons in the hindbrain drives mice to drink sodium solutions, and this appetite is distinct from thirst and hunger. These neurons are critical for animals to fully develop a sodium appetite following sodium depletion, although there is likely redundant circuitry.

The authors show that a normative approach to olfaction, Bayesian inference, reproduces much of the anatomy, physiology and behavior seen in real organisms. The model provides insight into how the olfactory system demixes odors, and, by extension, how other sensory systems extract relevant information from activity in peripheral organs.

The authors demonstrate that activity patterns in the default network during unguided spoken recollection of real-world events were similar between individuals recalling the same specific events. Patterns were altered between perception and recall in a systematic manner across brains. These results reveal a common spatial organization for memory representations.

In this study, the authors reveal distinct developmental programs underlying innate and learned olfactory behaviors by demonstrating that chemogenetic inactivation of neurons generated in neonatal mice impairs the behavioral response to aversive odorants, whereas inactivation of adult-born neurons impairs learning of novel food-related odors.

The authors describe a glutamatergic septoentorhinal pathway that provides running-speed-correlated input to MEC layer 2/3. The speed signal is integrated by several MEC cell classes and converted into speed-dependent output. This speed circuit may be important for the spatial computations of MEC neurons.

Auditory hair cells contain mechanotransduction channels that are activated by sound. The authors show that Piezo2, a mechanotransduction channel important for touch perception, is expressed in auditory hair cells. Surprisingly, Piezo2 is not the mechanotransduction channel essential for auditory perception and is instead observed after damage to hair cells.

Hunger-promoting AgRP neurons and satiety-promoting POMC neurons in the arcuate nucleus mediate homeostatic regulation of hunger. Yet a rapidly acting satiety component analogous to rapidly hunger-promoting AgRP neurons has been missing. The authors identify this missing satiety signal and show that it is carried by a novel subset of arcuate glutamatergic neurons.

The authors show that a direct pathway from the dorsal hippocampus to the prelimbic cortex is necessary for contextual fear memory strengthening. Molecular analyses and functional targeting revealed that prelimbic excitatory and inhibitory synapses have a critical role in promoting memory strengthening, while inhibiting extinction.

The strength of aversive learning is proportional to the intensity of aversive experiences, but how brain circuits set memory strength during learning is not known. The authors show that an amygdala-to-midbrain feedback circuit conveying information about future unpleasant experiences inhibits aversive processing during learning to calibrate memory strength.

Experimental autoimmune encephalomyelitis can be induced by strong activation of innate immunity. This subtype of EAE is resistant to interferon (IFN)-β treatment and is NLRP3 inflammasome independent. Its development is dependent upon lymphotoxin-β receptor LTβR and CXCR2, and can be inhibited by blocking these receptors. The IFNβ-resistant EAE subtype is characterized by minimal remission and neuronal damage induced by semaphorin-6B on CD4⁺ T cells.