Alpha (8–12 Hz) oscillations and default mode network (DMN) activity dominate the brain's intrinsic activity in the temporal and spatial domains, respectively. They are thought to play crucial roles in the spatiotemporal organization of the complex brain system. Relatedly, both have been implicated, often concurrently, in diverse neuropsychiatric disorders, with accruing electroencephalogram (EEG)/magnetoencephalogram and functional magnetic resonance imaging (fMRI) data linking these two neural activities both at rest and during key cognitive operations. Prominent theories and extant findings thus converge to suggest a mechanistic relationship between alpha oscillations and the DMN. Here, we leveraged simultaneous EEG–fMRI data acquired before and after alpha-frequency transcranial alternating current stimulation ( α -tACS) and observed that α -tACS tightened the dynamic coupling between spontaneous fluctuations in alpha power and DMN connectivity (especially, in the posterior DMN, between the posterior c...

Evolutionary pressures adapted insect chemosensation to their respective physiological needs and tasks in their ecological niches. Solitary nocturnal moths rely on their acute olfactory sense to find mates at night. Pheromones are detected with maximized sensitivity and high temporal resolution through mechanisms that are mostly unknown. While the inverse topology of insect olfactory receptors and heteromerization with the olfactory receptor coreceptor suggest ionotropic transduction via odorant-gated receptor–ion channel complexes, contradictory data propose amplifying G-protein–coupled transduction. Here, we used in vivo tip-recordings of pheromone-sensitive sensilla of male Manduca sexta hawkmoths at specific times of day (rest vs activity). Since the olfactory receptor neurons distinguish signal parameters in three consecutive temporal windows of their pheromone response (phasic; tonic; late, long-lasting), respective response parameters were analyzed separately. Disruption of G-protein–coupled transdu...

While ketamine, an NMDA receptor antagonist, is effective in treating major depression, studies have not addressed the safety of repeated ketamine infusions in depressed patients with comorbid alcohol use disorder (AUD). In this study, we aimed to determine whether a history of chronic social isolation and alcohol exposure alter the reinforcing properties of ketamine in male and female rats. Rats were pair-housed or socially isolated for 12 weeks and underwent intermittent access to 20% alcohol. Subsequently, rats underwent intravenous ketamine self-administration under a fixed ratio 1 schedule, followed by extinction training and one session of cue-induced reinstatement. Dendritic spine morphology was examined in the nucleus accumbens, an important area implicated in reward and motivation. Our results show that females self-administered more ketamine than males, a history of alcohol increased ketamine intake in females, and a history of isolation or alcohol independently increased ketamine intake in males...

Maintenance of normal structure of the enteric nervous system (ENS), which regulates key gastrointestinal functions, requires robust homeostatic mechanisms, since by virtue of its location within the gut wall, the ENS is subject to constant mechanical, chemical, and biological stressors. Using transgenic and thymidine analog-based experiments, we previously discovered that neuronal turnover—where continual neurogenesis offsets ongoing neuronal loss at steady state—represents one such mechanism. Although other studies confirmed that neuronal death continues into adulthood in the myenteric plexus of the ENS, the complicated nature of thymidine analog presents challenges in substantiating the occurrence of adult neurogenesis. Therefore, it is vital to employ alternative, well-recognized techniques to substantiate the existence of adult enteric neurogenesis in the healthy gut. Here, by using established methods of assessing nuclear DNA content and detecting known mitotic marker phosphor-histone H3 (pH3) in Hu+...

In models of visual spatial attention control, it is commonly held that top–down control signals originate in the dorsal attention network, propagating to the visual cortex to modulate baseline neural activity and bias sensory processing. However, the precise distribution of these top–down influences across different levels of the visual hierarchy is debated. In addition, it is unclear whether these baseline neural activity changes translate into improved performance. We analyzed attention-related baseline activity during the anticipatory period of a voluntary spatial attention task, using two independent functional magnetic resonance imaging datasets and two analytic approaches. First, as in prior studies, univariate analysis showed that covert attention significantly enhanced baseline neural activity in higher-order visual areas contralateral to the attended visual hemifield, while effects in lower-order visual areas (e.g., V1) were weaker and more variable. Second, in contrast, multivariate pattern anal...

Singular strategies for promoting axon regeneration and motor recovery after spinal cord injury (SCI) have been attempted with limited success. For instance, the deletion of RhoA and phosphatase and tensin homolog ( Pten ) (an extrinsic and intrinsic modulating factor, respectively) in corticospinal neurons (CSNs) promotes axon sprouting after thoracic SCI; however, it is unable to restore motor function. Here, we examine the effects of combining RhoA/Pten deletion in CSNs with chemogenetic neuronal stimulation on axonal growth and motor recovery after SCI in mice. We find that this combinatorial approach promotes greater axonal growth and presynaptic bouton formation in CSNs within the spinal cord compared with RhoA ; Pten deletion alone. Furthermore, chemogenetic neuronal stimulation of RhoA ; Pten -deleted CSNs improves forelimb performance in behavioral tasks after SCI compared with RhoA ; Pten deletion alone. These results demonstrate that combination therapies pairing genetic modifications with neuro...

Recent findings have shifted the view of cholecystokinin (CCK) from being a cellular neuronal marker to being recognized as a crucial neuropeptide pivotal in synaptic plasticity and memory processes. Despite its now appreciated importance in various brain regions and abundance in the basal ganglia, its role in the striatum, which is vital for motor control, remains unclear. This study sought to fill this gap by performing a comprehensive investigation of the role of CCK in modulating striatal medium spiny neuron (MSN) membrane properties, as well as the secondary somatosensory cortex S2 to MSN synaptic transmission and plasticity in rodents. Using in vivo optopatch-clamp recording in mice on identified MSNs, we showed that the application of CCK receptor Type 2 (CCK2R) antagonists decreases corticostriatal transmission in both direct and indirect pathway MSNs. Moving to an ex vivo rat preparation to maximize experimental access, we showed that CCK2R inhibition impacts MSN membrane properties by reducing sp...

Self-administration of addictive substances like heroin can couple the rewarding/euphoric effects of the drug with drug-associated cues, and opioid cue reactivity contributes to relapse vulnerability in abstinent individuals recovering from an opioid use disorder (OUD). Opioids are reported to alter the intrinsic excitability of medium spiny neurons (MSNs) in the nucleus accumbens (NAc), a key brain reward region linked to drug seeking, but how opioids alter NAc MSN neuronal excitability and the impact of altered MSN excitability on relapse-like opioid seeking remain unclear. Here, we discovered that self-administered, but not experimenter-administered, heroin reduced NAc protein levels of the voltage-gated sodium channel auxiliary subunit, SCN1b, in male and female rats. Viral-mediated reduction of NAc SCN1b increased the intrinsic excitability of MSNs, but without altering glutamatergic and GABAergic synaptic transmission. While reducing NAc SCN1b levels had no effect on acquisition of heroin self-admini...

Delayed motor development is an early clinical sign of fetal alcohol spectrum disorders. However, changes at the neural circuit level that underlie early motor differences are underexplored. The striatum, the principal input nucleus of the basal ganglia, plays an important role in motor learning in adult animals, and the maturation of the striatal circuit has been associated with the development of early motor behaviors. Here, we briefly exposed pregnant C57BL/6 dams to ethanol (5% w/w) in a liquid diet on embryonic days 13.5–16.5 and assessed the mouse progeny using a series of nine brief motor behavior tasks on postnatal days 2–14. Live brain slices were then obtained from behaviorally tested mice for whole-cell voltage- and current-clamp electrophysiology to assess GABAergic/glutamatergic synaptic activity and passive/active properties in two populations of striatal neurons: GABAergic interneurons and spiny striatal projection neurons. Electrophysiologically recorded spiny striatal projection neurons we...

The annual Society for Neuroscience (SfN) meeting is a bonanza of scientific achievement: famous keynote speakers, beautiful scientific results, and award ceremonies. This focus is exciting and invigorating but glosses over the many failures, mistakes, and rejections that typically lead to scientific success. Our goal has been to create a space within the annual SfN meeting for open conversation about scientific failure and, by doing so, increase transparency, resilience, and mental well-being within our community. In this article, we share the materials that we have used at SfN during the past 4 years (2021–2024) to promote discussions of scientific failure, including formal storytelling, individual and interactive games, and confessionals. For each activity, we provide the rationale and practical guidance regarding logistics and usage. We hope this will aid scientists interested in adapting the activities for their own communities or local events. We end with a call for scientific institutions to commit ...