[Learning and Neural Activity: Beyond Localization].

Learning is classified into two types: "classical conditioning," which modifies simple reflexes, and "operant conditioning," which modifies complex voluntary behaviors. The neural circuits underlying these two types differ significantly. During the learning process of operant conditioning tasks, various changes in firing rate and firing synchrony of neurons can be observed across multiple brain regions.

An intra-oral flavor detection task in freely moving mice.

Flavor plays a critical role in the pleasure of food. Flavor research has mainly focused on human subjects and revealed that many brain regions are involved in flavor perception. However, animal models for elucidating the mechanisms of neural circuits are lacking.

Rats adaptively seek information to accommodate a lack of information.

Metacognition is the ability to adaptively control one's behavior by referring to one's own cognitive processes. It is thought to contribute to learning in situations where there is insufficient information available from the environment. Information-seeking behavior is a type of metacognition in which one confirms the necessary information only when one does not have the necessary and sufficient information to accomplish a task.

Efficacy of cEEG and hepatic function to diagnose early acute encephalopathy.

Background: Early treatment may improve the prognosis of acute encephalopathy (AE). However, methods for early diagnosis have not yet been established. In this paper, we examined methods for the early diagnosis of AE.

Imaging of extrapontine myelinolysis preceding central pontine myelinolysis in a case of ornithine transcarbamylase deficiency with hyperammonaemia and hypokalaemia.

Background: Patients with ornithine transcarbamylase deficiency (OTCD) often present with severe hyperammonaemia. We report a case of osmotic demyelination syndrome (ODS) secondary to the treatment of hyperammonaemia due to OTCD, a disease requiring early diagnosis, as it can have a severe prognosis.

Case: A girl toddler was brought to the hospital with a complaint of somnolence, presenting with hyperammonaemia and liver failure, and was diagnosed with OTCD.

Auditory Cortex Neurons Show Task-Related and Learning-Dependent Selectivity toward Sensory Input and Reward during the Learning Process of an Associative Memory Task.

The activity of primary auditory cortex (A1) neurons is modulated not only by sensory inputs but also by other task-related variables in associative learning. However, it is unclear how A1 neural activity changes dynamically in response to these variables during the learning process of associative memory tasks. Therefore, we developed an associative memory task using auditory stimuli in rats.

Medial prefrontal cortex stimulation disrupts observational learning in Barnes maze in rats.

Observational learning, which improves one's own behavior by observing the adaptive behavior of others, has been experimentally demonstrated in primates and rodents in several behavioral studies, including our previous study. However, its neural mechanisms remain unclear. We electrically stimulated the brain regions of rats and disturbed their neural activities during observation periods in the observational learning task using Barnes maze.

Hippocampal CA1 Neurons Represent Positive Feedback During the Learning Process of an Associative Memory Task.

The hippocampus is crucial for forming associations between environmental stimuli. However, it is unclear how neural activities of hippocampal neurons dynamically change during the learning process. To address this question, we developed an associative memory task for rats with auditory stimuli.

Over-representation of fundamental decision variables in the prefrontal cortex underlies decision bias.

The brain is organized into anatomically distinct structures consisting of a variety of projection neurons. While such evolutionarily conserved neural circuit organization underlies the innate ability of animals to swiftly adapt to environments, they can cause biased cognition and behavior. Although recent studies have begun to address the causal importance of projection-neuron types as distinct computational units, it remains unclear how projection types are functionally organized in encoding variables during cognitive tasks.

Bi-directional encoding of context-based odors and behavioral states by the nucleus of the lateral olfactory tract.

The nucleus of the lateral olfactory tract (NLOT) is not only a part of the olfactory cortex that receives olfactory sensory inputs but also a part of the cortical amygdala, which regulates motivational behaviors. To examine how neural activity of the NLOT is modulated by decision-making processes that occur during various states of learned goal-directed behaviors, we recorded NLOT spike activities of mice performing odor-guided go/no-go tasks to obtain a water reward. We observed that several NLOT neurons exhibited sharp go-cue excitation and persistent no-go-cue suppression responses triggered by an odor onset.

Contribution of non-sensory neurons in visual cortical areas to visually guided decisions in the rat.

It is widely assumed that trial-by-trial variability in visual detection performance is explained by the fidelity of visual responses in visual cortical areas influenced by fluctuations of internal states, such as vigilance and behavioral history. However, it is not clear which neuronal ensembles represent such different internal states. Here, we utilized a visual detection task, which distinguishes internal states in response to identical stimuli, while recording neurons simultaneously from the primary visual cortex (V1) and the posterior parietal cortex (PPC).

Basilar Artery Dissection Complicated with Infective Endocarditis.

A 14 year-old boy developed infective endocarditis of the mitral valve caused by Methicillin-sensitive Staphylococcus aureus and became comatose. Isolated basilar artery dissection was initially observed on the 3rd day by magnetic resonance imaging (MRI), ie, it did not exist on day 1. He underwent successful urgent mitral valve repair on the 5th day because of highly mobile vegetations and a newly emerged brain infarction under optimal antibiotic administration.

Markedly long pause due to sinus arrest during dexmedetomidine use and nasal continuous positive airway pressure in two infants with respiratory syncytial virus infection.

Nasal respiratory support for infants with respiratory distress caused by respiratory syncytial (RS) virus infection sometimes requires appropriate sedation. Dexmedetomidine can be an alternative sedative because of its advantage of less frequent respiratory suppression. We report the cases of twin infants with RS virus infection who showed unreported long pauses (4 and 10 s) due to sinus arrest while receiving dexmedetomidine.

Tuning of olfactory cortex ventral tenia tecta neurons to distinct task elements of goal-directed behavior.

The ventral tenia tecta (vTT) is a component of the olfactory cortex and receives both bottom-up odor signals and top-down signals. However, the roles of the vTT in odor-coding and integration of inputs are poorly understood. Here, we investigated the involvement of the vTT in these processes by recording the activity from individual vTT neurons during the performance of learned odor-guided reward-directed tasks in mice.

Dynamic coordination of the perirhinal cortical neurons supports coherent representations between task epochs.

Cortical neurons show distinct firing patterns across multiple task epochs characterized by different computations. Recent studies suggest that such distinct patterns underlie dynamic population code achieving computational flexibility, whereas neurons in some cortical areas often show coherent firing patterns across epochs. To understand how coherent single-neuron code contributes to dynamic population code, we analyzed neural responses in the rat perirhinal cortex (PRC) during cue and reward epochs of a two-alternative forced-choice task.

Left-right functional difference of the rat dorsal hippocampus for short-term memory and long-term memory.

The existence of left-right hemispheric differences has been suggested not only in humans but also in rodents. In recent studies, left-right anatomical and functional differences of the rodent hippocampus have been revealed. However, there is only one report investigating the left-right difference for short-term memory (STM), and the left-right difference for long-term memory (LTM) is not consistent among previous studies.

Contribution of the prefrontal cortex and basolateral amygdala to behavioral decision-making under reward/punishment conflict.

Rationale: Control of reward-seeking behavior under conditions of punishment is an important function for survival.

Objectives And Methods: We designed a task in which rats could choose to either press a lever and obtain a food pellet accompanied by a footshock or refrain from pressing the lever to avoid footshock, in response to tone presentation. In the task, footshock intensity steadily increased, and the task was terminated when the lever press probability reached < 25% (last intensity).

First Report of Fatal Secondary Abdominal Compartment Syndrome Induced by Intestinal Gas Accumulation without Organic Occlusive Intestinal Lesion in a Child with Sepsis.

BACKGROUND Abdominal compartment syndrome (ACS), characterized by an increased intra-abdominal pressure and new-onset organ dysfunction, is a critical and potentially fatal condition, with no case of ACS caused by intestinal gas without intestinal lesion being reported to date. CASE REPORT A 2-year-old girl with a chromosomal abnormality of 1p36 deletion presented with fever and diarrhea following upper-gastrointestinal series for the evaluation of gastroesophageal reflux. After 20 days, she experienced septic shock and multiple-organ failure, accompanied with rapidly growing, severe abdominal distension.

Enhanced Theta and High-Gamma Coupling during Late Stage of Rule Switching Task in Rat Hippocampus.

Hippocampal oscillations, particularly theta (6-12 Hz) and gamma (30-90 Hz) frequency bands, play an important role in several cognitive functions. Theta and gamma oscillations show cross-frequency coupling (CFC), wherein the phase of theta rhythm modulates the amplitude of the gamma oscillation, and this CFC is believed to reflect cell assembly dynamics in cognitive processes. Previous studies have reported that CFC strength correlates with the learning process.

GABAergic neurons in the olfactory cortex projecting to the lateral hypothalamus in mice.

Olfaction guides goal-directed behaviours including feeding. To investigate how central olfactory neural circuits control feeding behaviour in mice, we performed retrograde tracing from the lateral hypothalamus (LH), an important feeding centre. We observed a cluster of retrogradely labelled cells distributed in the posteroventral region of the olfactory peduncle.

Reinforcement schedules differentially affect learning in neuronal operant conditioning in rats.

Operant conditioning of neuronal activity is a core process for better operation of brain-machine interfaces. However, few studies have investigated the role of reinforcement schedules in neuronal operant conditioning, although they are very effective in behavioral operant conditioning. To test the effect of different reinforcement schedules, the authors trained single-neuron activity in the motor cortex using fixed ratio (FR) and variable ratio (VR) schedules in rats.

Dynamics of memory engrams.

In this update article, we focus on "memory engrams", which are traces of long-term memory in the brain, and emphasizes that they are not static but dynamic. We first introduce the major findings in neuroscience and psychology reporting that memory engrams are sometimes diffuse and unstable, indicating that they are dynamically modified processes of consolidation and reconsolidation. Second, we introduce and discuss the concepts of cell assembly and engram cell, the former has been investigated by psychological experiments and behavioral electrophysiology and the latter is defined by recent combination of activity-dependent cell labelling with optogenetics to show causal relationships between cell population activity and behavioral changes.

An observational learning task using Barnes maze in rats.

Observational learning, which modulates one's own behavior by observing the adaptive behavior of others, is crucial for behaving efficiently in social communities. Although many behavioral experiments have reported observational learning in monkeys and humans, its neural mechanisms are still unknown. In order to conduct neuroscientific researches with recording neural activities, we developed an observational learning task for rats.

Subjective decision threshold for accurate visual detection performance in rats.

The dissociation between a subjective-criterion performance and forced performance in a sensory detection can provide critical insights into the neural correlates of sensory awareness. Here, we established a behavioral task for rats to test their spatial-visual cue detection ability, using a two alternative choice task with and without a third choice option where animals get rewards only in the objective absence of a visual cue. In the trials without the third option, spatial choice accuracy decreased from near perfect to near chance levels as the visual cue brightness decreased.