Mitral cells (MCs) and tufted cells (TCs) in the olfactory bulb (OB) act as an input convergence hub and transmit information to higher olfactory areas. Since first characterized, they have been classed as distinct projection neurons based on size and location: laminarly arranged MCs with a diameter larger than 20 µm in the mitral layer (ML) and smaller TCs spread across both the ML and external plexiform layers (EPL). Recent in vivo work has shown that these neurons encode complementary olfactory information, akin to parallel channels in other sensory systems. Yet, many ex vivo studies still collapse them into a single class, mitral/tufted, when describing their physiological properties and impact on circuit function. Using immunohistochemistry and whole-cell patch–clamp electrophysiology in fixed or acute slices from adult mice, we attempted to align in vivo and ex vivo data and test a soma size-based classifier of bulbar projection neurons using passive and intrinsic firing properties. We found that the...

Facial paralysis is characterized by an injury to the facial nerve, causing the loss of the functions of the structures that it innervates, as well as changes in the motor cortex. Current models have some limitations for the study of facial paralysis, such as movement restriction, the absence of studying awake animals in behavioral contexts, and the lack of a model that fully evaluates facial movements. The development of an algorithm capable of automatically inferring facial paralysis and overcoming the existing limitations is proposed in this work. In C57/BL6J mice, we produced both irreversible and reversible facial paralysis. Video recordings were made of the faces of paralyzed mice to develop an algorithm for detecting facial paralysis applied to mice, which allows us to predict the presence of reversible and irreversible facial paralysis automatically. At the same time, the algorithm was used to track facial movement during gustatory stimulation and extracellular electrophysiological recordings in th...

Neuroinflammation has been widely recognized as the primary pathophysiological mechanism underlying ischemic white matter lesions (IWML) in chronic cerebral hypoperfusion (CCH). Adenosine A2A receptor (A2aR), an important adenosine receptor, exhibits a dual role in neuroinflammation by modulating both proinflammatory and anti-inflammatory responses. This study aimed to investigate the specific functions and mechanisms of A2aR in neuroinflammation. The findings revealed that A2aR initially exerted a proinflammatory role in the CCH model, transitioning to an anti-inflammatory role in later stages by regulating the phenotypic transformation of microglia. Further analyses using coimmunoprecipitation couple with mass spectrometry, in situ proximity ligation assay, AlphaFold protein structure prediction, [35S]GTPγS binding assay, and NanoBiT technology demonstrated that A2aR formed heteromers with mGluR5 during the early stage of CCH under high glutamate conditions, promoting the polarization of microglia toward...

Humans and nonhumans alike often make choices to gain information, even when the information cannot be used to change the outcome. Prior research has shown that the anterior cingulate cortex (ACC) is important for evaluating options involving reward-predictive information. Here we studied the role of ACC in information choices using optical inhibition to evaluate the contribution of this region during specific epochs of decision-making. Rats could choose between an uninformative option followed by a cue that predicted reward 50% of the time versus a fully informative option that signaled outcomes with certainty but was rewarded only 20% of the time. Reward seeking during the informative S+ cue decreased following ACC inhibition, indicating a causal contribution of this region in supporting reward expectation to a cue signaling reward with certainty. Separately in a positive control experiment and in support of a known role for this region in sustaining high-effort behavior for preferred rewards, we observe...

How humans achieve such a high degree of prosocial behavior is a subject of considerable interest. Exploration of the neural foundations of human prosociality has garnered significant attention in recent decades. Nevertheless, the neural mechanisms underlying human prosociality remain to be elucidated. To address this knowledge gap, we analyzed multimodal brain imaging data and data from 15 economic games. The results revealed several significant associations between brain characteristics and prosocial behavior, including stronger interhemispheric connectivity and larger corpus callosum volume. Greater functional segregation and integration, alongside fewer myelin maps combined with a thicker cortex, were linked to prosocial behavior, particularly within the social brain regions. The current study demonstrates that these metrics serve as brain markers of human prosocial behavior and provides novel insights into the structural and functional brain basis of human prosocial behavior.

Electrophysiology recordings from the brain using laminar multielectrode arrays allow researchers to measure the activity of many neurons simultaneously. However, laminar microelectrode arrays move relative to their surrounding neural tissue for a variety of reasons, such as pulsation, changes in intracranial pressure, and decompression of neural tissue after insertion. Inferring and correcting for this motion stabilizes the recording and is critical to identify and track single neurons across time. Such motion correction is a preprocessing step of standard spike-sorting methods. However, estimating motion robustly and accurately in electrophysiology recordings is challenging due to the stochasticity of the neural data. To tackle this problem, we introduce MEDiCINe ( M otion E stimation by Di stributional C ontrastive I nference for Ne urophysiology), a novel motion estimation method. We show that MEDiCINe outperforms existing motion estimation methods on an extensive suite of simulated neurophysiology rec...

Beta event-related spectral perturbation, including bilateral movement-related beta desynchronization (MRBD) and postmovement beta synchronization (PMBS), can be evoked by unilateral speed movement. A potential correlation might exist between power (de)synchronization and interhemispheric coherence during movement execution. However, during the PMBS phase, the existence of interhemispheric coupling and the effect of speed on it are largely undiscovered. To answer this question, we investigated eight healthy, right-handed volunteers using a combination of electroencephalography, transcranial magnetic stimulation, and electromyography. We explored interhemispheric (directed) coherence during isotonic right index finger abduction movements at two speeds: ballistic and self-paced. We discovered that (1) interhemispheric coherence was greater during the PMBS than during the MRBD period. Furthermore, ballistic movement induced a larger coherence during the PMBS period, but not during the MRBD period. (2) In the ...

Stress is a common occurrence for military personnel. This can include the stress of deployment and active combat. Anxiety is considered a reaction to stress, and with anxiety-related disorders on the rise, it is imperative that stress be considered a preexisting condition when studying a number of neurological conditions. To determine the effects of stress on the behavioral outcomes of traumatic brain injury (TBI), we used a 3 d acute unpredictable stress (AUS) model followed by blast-induced neurotrauma (BINT) to assess social anhedonia and anxiety-like behaviors in male and female rats. The animals were divided into four groups including unstressed and uninjured control (Con), stress-only animals (AUS), injury-only animals (BINT), and animals that received both stress and injury (AUS + BINT). In the males, behavioral tests such as elevated plus and three-chamber sociability (3-CS) showed that stress plays a dominant role in determining behavioral outcomes after TBI with the AUS + BINT animals behaving m...

Impulsivity is often considered a risk factor for drug addiction; however, not all evidence supports this view. In the present study, we used a food reward delay-discounting task (DDT) to categorize rats as low-, middle-, and high-impulsive but failed to find any difference among these groups in the acquisition and maintenance of cocaine self-administration (SA), regardless of electrical footshock punishment. Additionally, there were no group differences in locomotor responses to acute cocaine in rats with or without a history of cocaine SA. Unexpectedly, chronic cocaine SA selectively increased impulsive choice in low-impulsive rats. Resting-state fMRI analysis revealed a positive correlation between impulsivity and cerebral blood volume in the midbrain, thalamus, and auditory cortex. Using these three regions as seeds, we observed a negative correlation between impulsivity and functional connectivity between the midbrain and frontal cortex, as well as between the thalamus and frontal cortex (including th...

When attempting to concurrently perform two distinct cognitive tasks, the performance of either task is frequently compromised. This phenomenon is known as dual-task interference. Although multiple task features have been postulated to influence on dual-task interference, the primary determinant remains unclear. The determinant factor causing dual-task interference is an important issue to understand its mechanism and associated functions including switching tasks and planning task order. The present study investigated this issue using monkeys and three behavioral tasks requiring distinct cognitive processes (spatial working memory, SWM; working memory and long-term memory of objects, PA; object working memory, DMS) and manipulating task pair (SWM and PA or SWM and DMS), task order (fixed or randomized), and task difficulty (different delay lengths). The task introduced first showed better performance as compared with the task introduced second, suggesting the task order as an important factor. However, th...