Standard economic indicators provide an incomplete picture of what we value both as individuals and as a society. Furthermore, canonical macroeconomic measures, such as GDP, do not account for non-market activities (e.g., cooking, childcare) that nevertheless impact well-being. Here, we introduce a computational tool that measures the affective value of experiences (e.g., playing a musical instrument without errors). We go on to validate this tool with neural data, using fMRI to measure neural activity in male and female human subjects performing a reinforcement learning task that incorporated periodic ratings of subjective affective state. Learning performance determined level of payment (i.e., extrinsic reward). Crucially, the task also incorporated a skilled performance component (i.e., intrinsic reward) which did not influence payment. Both extrinsic and intrinsic rewards influenced affective dynamics, and their relative influence could be captured in our computational model. Individuals for whom intri...

Na+-sensitivity is a unique feature of Na+-activated K+ (KNa) channels, making them naturally suited to counter a sudden influx in Na+ ions. As such, it has long been suggested that KNa channels may serve a protective function against excessive excitation associated with neuronal injury and disease. This hypothesis, however, has remained largely untested. Here, we examine KNa channels encoded by the Drosophila Slo2 ( dSlo2 ) gene in males and females. We show that dSlo2/KNa channels are selectively expressed in cholinergic neurons in the adult brain, as well as in glutamatergic motor neurons, where dampening excitation may function to inhibit global hyperactivity and seizure-like behavior. Indeed, we show that effects of feeding Drosophila a cholinergic agonist are exacerbated by the loss of dSlo2/KNa channels. Similar to mammalian Slo2/KNa channels, we show that dSlo2/KNa channels encode a TTX-sensitive K+ conductance, indicating that dSlo2/KNa channels can be activated by Na+ carried by voltage-dependent...

SCN8A epileptic encephalopathy is a devastating epilepsy syndrome caused by mutant SCN8A which encodes the voltage-gated sodium channel NaV1.6. To date, it is unclear if and how inhibitory interneurons, which express NaV1.6, influence disease pathology. Using both sexes of a transgenic mouse model of SCN8A encephalopathy, we found that selective expression of the R1872W SCN8A mutation in somatostatin (SST) interneurons was sufficient to convey susceptibility to audiogenic seizures. Patch-clamp electrophysiology experiments revealed that SST interneurons from mutant mice were hyperexcitable but hypersensitive to action potential failure via depolarization block under normal and seizure-like conditions. Remarkably, GqDREADD-mediated activation of wild-type SST interneurons resulted in prolonged electrographic seizures and was accompanied by SST hyperexcitability and depolarization block. Aberrantly large persistent sodium currents, a hallmark of SCN8A mutations, were observed and were found to contribute dir...

Signal transmission in the brain propagates via distinct oscillatory frequency bands but the aperiodic component - 1/f activity - almost always co-exists which most of the previous studies have not sufficiently taken into consideration. We used a recently proposed parameterisation model that delimits the oscillatory and aperiodic components of neural dynamics on lifespan ageing data collected from human participants using Magnetoencephalography (MEG). Since, healthy ageing underlines an enormous change in local tissue properties, any systematic relationship of 1/f activity would highlight their impact on the self-organized critical functional states. Furthermore, we have used patterns of correlation between aperiodic background and metrics of behaviour, to understand the domain general effects of 1/f activity. We suggest that age-associated global change in 1/f baseline, alters the functional critical states of the brain affecting the global information processing impacting critically all aspects of cognit...

Although we use our visual and tactile sensory systems interchangeably for object recognition on a daily basis, little is known about the mechanism underlying this ability. This study examined how 3D shape features of objects form two congruent and interchangeable visual and tactile perceptual spaces in healthy male and female participants. Since active exploration plays an important role in shape processing, a virtual reality environment was used to visually explore 3D objects called digital embryos without using the tactile sense. In addition, during the tactile procedure, blindfolded participants actively palpated a 3D-printed version of the same objects with both hands. We first demonstrated that the visual and tactile perceptual spaces were highly similar. We then extracted a series of 3D shape features to investigate how visual and tactile exploration can lead to the correct identification of the relationships between objects. The results indicate that both modalities share the same shape features to...

Relapse is a major challenge to the treatment of substance use disorders. A progressive increase in cue-induced drug craving, termed incubation of craving, is observed after withdrawal from multiple drugs of abuse in humans and rodents. Incubation of cocaine craving involves strengthening of excitatory synapses onto nucleus accumbens (NAc) medium spiny neurons via postsynaptic accumulation of high-conductance Ca2+-permeable AMPA receptors. This enhances reactivity to drug-associated cues and is required for the expression of incubation. Additionally, incubation of cocaine craving is associated with loss of the synaptic depression normally triggered by stimulation of metabotropic glutamate receptor 5 (mGlu5), leading to endocannabinoid production, and expressed presynaptically via cannabinoid receptor 1 activation. Previous studies have found alterations in mGlu5 and Homer proteins associated with the loss of this synaptic depression. Here we conducted co-immunoprecipitation studies to investigate associati...

Knee joint trauma can cause an osteochondral defect (OD), a risk factor for osteoarthritis and cause of debilitating pain in patients. Rodent OD models are less translatable due to their smaller joint size and open growth plate. This study proposes sheep as a translationally relevant model to understand the neuronal basis of OD pain. Unilateral 6 mm deep OD was induced in adult female sheep. 2-6 weeks post-operation, lumbar dorsal root ganglia (DRG) neurons were collected from the contralateral and OD side of operated sheep. Functional assessment of neuronal excitability and activity of the pain-related ion channels TRPV1 and P2X3 was carried out using electrophysiology and Ca2+-imaging. Immunohistochemistry was utilized to verify expression of pain-related proteins. We observed that an increased proportion of OD DRG neurons (sheep, N = 3; Ctrl neurons, n =15, OD neurons, n = 16) showed spontaneous electrical excitability (Ctrl: 20.33 ± 4.5%; OD: 50 ± 10%; p = 0.009, unpaired t-test) and an increased propo...

Autism spectrum disorders (ASDs) are characterized by abnormal behavioral traits arising from neural circuit dysfunction. While a number of genes have been implicated in ASDs, in most cases, a clear understanding of how mutations in these genes lead to circuit dysfunction and behavioral abnormality is absent. The autism susceptibility candidate 2 ( AUTS2 ) gene is one such gene, associated with ASDs, intellectual disability and a range of other neurodevelopmental conditions. Yet, the role of AUTS2 in neural development and circuit function is not at all known. Here, we undertook functional analysis of Auts2a, the main homolog of AUTS2 in zebrafish, in the context of the escape behavior. Escape behavior in wild type zebrafish is critical for survival and is therefore, reliable, rapid, and has well-defined kinematic properties. Auts2a mutant zebrafish are viable, have normal gross morphology and can generate escape behavior with normal kinematics. However, the behavior is unreliable and delayed, with high tr...

Human infants who suffer from intrauterine growth restriction (IUGR), which is a failure to attain their genetically pre-determined weight, are at increased risk for postnatal learning and memory deficits. Hippocampal dentate gyrus (DG) granule neurons play an important role in memory formation, however it is unknown whether IUGR affects embryonic DG neurogenesis, which could provide a potential mechanism underlying abnormal postnatal learning and memory function. Using a mouse model of the most common cause of IUGR, induced by hypertensive disease of pregnancy, we first assessed adult learning and memory function. We quantified the percentages of embryonic hippocampal DG neural stem and progenitor cells and developing glutamatergic granule neurons, as well as hippocampal volumes and neuron cell count and morphology 18 and 40 days after delivery. We characterized the differential embryonic hippocampal transcriptomic pathways between appropriately-grown and IUGR mouse offspring. We found that IUGR offspring...

Epilepsy affects 3.4 million people in the United States, and despite availability of numerous antiepileptic drugs, 36% of patients have uncontrollable seizures, which severely impacts quality of life. High frequency oscillations (HFOs) are a potential biomarker of epileptogenic tissue that could be useful in surgical planning. As a result, research into the efficacy of HFOs as a clinical tool has increased over the last two decades. However, detection and identification of these transient rhythms in intracranial electroencephalographic recordings remain time-consuming and challenging. Although automated detection algorithms have been developed, their results are widely inconsistent, reducing reliability. Thus, manual marking of HFOs remains the gold standard, and manual review of automated results is required. However, manual marking and review are time-consuming and can still produce variable results due to their subjective nature and the limitations in functionality of existing open-source software. Our...