Studies employing EEG to measure somatosensory responses have been typically optimized to compute event-related potentials in response to discrete events. However, tactile interactions involve continuous processing of nonstationary inputs that change in location, duration, and intensity. To fill this gap, this study aims to demonstrate the possibility of measuring the neural tracking of continuous and unpredictable tactile information. Twenty-seven young adults (females, 15) were continuously and passively stimulated with a random series of gentle brushes on single fingers of each hand, which were covered from view. Thus, tactile stimulations were unique for each participant and stimulated fingers. An encoding model measured the degree of synchronization between brain activity and continuous tactile input, generating a temporal response function (TRF). Brain topographies associated with the encoding of each finger stimulation showed a contralateral response at central sensors starting at 50 ms and peaking ...

Spike-and-wave discharges (SWDs) and sleep spindles are characteristic electroencephalographic (EEG) hallmarks of absence seizures and nonrapid eye movement sleep, respectively. They are commonly generated by the cortico–thalamo–cortical network including the thalamic reticular nucleus (TRN). It has been reported that SWD development is accompanied by a decrease in sleep spindle density in absence seizure patients and animal models. However, whether the decrease in sleep spindle density precedes, coincides with, or follows, the SWD development remains unknown. To clarify this, we exploited Pvalb -tetracycline transactivator (tTA)::tetO-ArchT (PV-ArchT) double-transgenic mouse, which can induce an absence seizure phenotype in a time-controllable manner by expressing ArchT in PV neurons of the TRN. In these mice, EEG recordings demonstrated that a decrease in sleep spindle density occurred 1 week before the onset of typical SWDs, with the expression of ArchT. To confirm such temporal relationship observed in...

Rett syndrome (RTT), a severe neurodevelopmental disorder caused by mutations in the MeCP2 gene, is characterized by cognitive and social deficits. Previous studies have noted hypoactivity in the medial prefrontal cortex (mPFC) pyramidal neurons of MeCP2-deficient mice (RTT mice) in response to both social and nonsocial stimuli. To further understand the neural mechanisms behind the social deficits of RTT mice, we monitored excitatory pyramidal neurons in the prelimbic region of the mPFC during social interactions in mice. These neurons’ activity was closely linked to social preference, especially in wild-type mice. However, RTT mice showed reduced social interest and corresponding hypoactivity in these neurons, indicating that impaired mPFC activity contributes to their social deficits. We identified six mPFC neural ensembles selectively tuned to various stimuli, with RTT mice recruiting fewer neurons to ensembles responsive to social interactions and consistently showing lower stimulus-ON ensemble transi...

Some visual neurons in the dragonfly ( Hemicordulia tau ) optic lobe respond to small, moving targets, likely underlying their fast pursuit of prey and conspecifics. In response to repetitive targets presented at short intervals, the spiking activity of these “small target motion detector” (STMD) neurons diminishes over time. Previous experiments limited this adaptation by including intertrial rest periods of varying durations. However, the characteristics of this effect have never been quantified. Here, using extracellular recording techniques lasting for several hours, we quantified both the spatial and temporal properties of STMD adaptation. We found that the time course of adaptation was variable across STMD units. In any one STMD, a repeated series led to more rapid adaptation, a minor accumulative effect more akin to habituation. Following an adapting stimulus, responses recovered quickly, though the rate of recovery decreased nonlinearly over time. We found that the region of adaptation is highly lo...

A new era of disease-modifying therapy for Alzheimer's disease (AD) arrived in 2021 following the Food and Drug Administration's (FDA) decision to grant accelerated approval for aducanumab, an anti-β-amyloid (Aβ) monoclonal antibody designed to target Aβ aggregates, a biological component of AD. More recently, trial outcomes for lecanemab and donanemab, two additional antibodies of this drug class, have shown favorable and significant slowing of metrics for cognitive and functional decline. Lecanemab and donanemab have since received similar FDA approval to aducanumab in January 2023 and July 2024, respectively. Given that these therapies are a clearly emerging tool in the repertoire of clinicians treating AD and related dementias, a critical dialogue has been ongoing regarding the potential impacts and place for these therapies. Here, we seek to contextualize this debate by first considering factors involved in theoretically extrapolating current randomized control trial outcomes to estimate meaningful cl...

In the article “The Lack of Synapsin Alters Presynaptic Plasticity at Hippocampal Mossy Fibers in Male Mice” by Felicitas Bruentgens, Laura Moreno Velasquez, Alexander Stumpf, Daniel Parthier, Jörg Breustedt, Fabio Benfenati, Dragomir Milovanovic, …

Retinal ganglion cell (RGC) axons provide direct input into several brain regions, including the dorsal lateral geniculate nucleus (dLGN), which is important for image-forming vision, and the ventrolateral geniculate nucleus (vLGN), which is associated with nonimage-forming vision. Through both activity- and morphogen-dependent mechanisms, retinal inputs play important roles in the development of dLGN, including the refinement of retinal projections, morphological development of thalamocortical relay cells (TRCs), timing of corticogeniculate innervation, and recruitment and distribution of inhibitory interneurons. In contrast, little is known about the role of retinal inputs in the development of vLGN. Grossly, vLGN is divided into two domains, the retinorecipient external vLGN (vLGNe) and nonretinorecipient internal vLGN (vLGNi). Studies previously found that vLGNe consists of transcriptionally distinct GABAergic subtypes distributed into at least four adjacent laminae. At present, it remains unclear whet...

The field of neuroscience embodies a very active international scientific community that drives the need for neuroscience training programs to internationalize their training efforts. Increasing efforts to attract and acclimate students will leverage diverse scientific collaboration with academic success. This webinar showcases two neuroscience training programs, and describe how each support their international student body by addressing language barriers, pre-course requirements, and general adaptation to a new country. The program also features the perspectives of two students.

Contrast sensitivity, which constrains human vision, decreases from fovea to periphery, from the horizontal to the vertical meridian, and from the lower vertical to the upper vertical meridian. The Contrast Sensitivity Function (CSF) depicts how contrast sensitivity depends on spatial frequency (SF). To compensate for these visual constraints, we constantly make saccadic eye movements to foveate on relevant objects in the scene. Already before saccade onset, presaccadic attention shifts to the saccade target and enhances perception. However, it is unknown whether and how it modulates the interplay between contrast sensitivity and SF, and if this effect varies around polar angle locations. Contrast sensitivity enhancement may result from a horizontal or vertical shift of the CSF, increase in bandwidth, or any combination. In addition, presaccadic attention could enhance contrast sensitivity similarly around the visual field, or it could benefit perception more at locations with poorer performance (i.e., ver...

Much of what has been discovered concerning neurophysiological mechanisms can be credited to ex vivo biomedical experiments. Beyond these discoveries, ex vivo research techniques have enhanced the global understanding of human physiology and pathology in almost every biomedical specialty. Naturally, ex vivo experiments are among the most desired methods of research, particularly in the field of neuroscience. Ex vivo experiment platforms may be purchased commercially. However, their substantial cost and sometimes limited availability can render them inaccessible to many research labs. Moreover, these manufactured systems are often rigid in function with no possibility of customization, severely narrowing their capabilities. However, developing essential components for ex vivo laboratory systems with a fused deposition modeling (FDM) printer provides a practical solution to each of these obstacles. Here, we provide the designs and construction process for an easily accessible, highly adaptable recording stag...