The study of the neural circuitry underlying complex mammalian decision-making, particularly cognitive flexibility, is critical for understanding psychiatric disorders. To test cognitive flexibility, as well as potentially other decision-making paradigms involving multimodal sensory perception, we developed FlexRig, an open-source, modular behavioral platform for use in head-fixed mice. FlexRig enables the administration of tasks relying upon olfactory, somatosensory, and/or auditory cues and employing left and right licking as a behavior readout and reward delivery mechanism. The platform includes hardware and software components that are customizable, scalable, and portable, supporting a variety of behavioral assays. Using FlexRig, we established a head-fixed task to model attentional set-shifting, offering a new tool for neuroscience research that enhances the capacity for investigation of cognitive processes and their neural substrates, with broad applications in translational neuroscience.

Brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) are known to contribute to both protective and pronociceptive processes. However, their contribution to neuropathic pain after spinal cord injury (SCI) needs further investigation. In a recent study utilizing TrkBF616A mice, it was shown that systemic pharmacogenetic inhibition of TrkB signaling with 1NM-PP1 (1NMP) immediately after SCI delayed the onset of pain hypersensitivity, implicating maladaptive TrkB signaling in pain after SCI. To examine potential neural mechanisms underlying the behavioral outcome, patch-clamp recording was performed in small-diameter dissociated thoracic (T) dorsal root ganglia (DRG) neurons to evaluate TrkB signaling in uninjured mice and after T10 contusion SCI. Bath-applied 7,8-dihydroxyflavone (7,8-DHF), a selective TrkB agonist, induced a robust inward current in neurons from uninjured mice, which was attenuated by 1NMP treatment. SCI also decreased 7,8-DHF-induced current while increasing th...

Fragile X autosomal homolog 1 (FXR1), a member of the fragile X messenger riboprotein 1 family, has been linked to psychiatric disorders including autism and schizophrenia. Parvalbumin (PV) interneurons play critical roles in cortical processing and have been implicated in FXR1-linked mental illnesses. Targeted deletion of FXR1 from PV interneurons in mice has been shown to alter cortical excitability and elicit schizophrenia-like behavior. This indicates that FXR1 regulates behaviorally relevant electrophysiological functions in PV interneurons. We therefore expressed a genetically encoded hybrid voltage sensor in PV interneurons and used voltage imaging in slices of mouse somatosensory cortex to assess the impact of targeted FXR1 deletion. These experiments showed that PV interneurons lacking FXR1 had excitatory synaptic potentials with larger amplitudes and shorter latencies compared with wild type. Synaptic potential rise-times, decay-times, and half-widths were also impacted to degrees that varied bet...

The anterior hypothalamic area (AHA) is a key brain region for orchestrating defensive behaviors. Using in vivo calcium imaging in mice, we observed that AHA neuronal activity increases during footshock delivery and footshock-associated auditory cues. We found that following shock-induced increases in AHA activity, a decrease in activity coincides with the onset of grooming behavior. Next, we optogenetically activated the projections from the ventromedial hypothalamus (VMH) to the AHA and observed that photoactivation of the VMH→AHA pathway drives avoidance. Interestingly, repetitive grooming behavior occurs following cessation of stimulation. To identify changes in brain-wide activity patterns that occur due to optogenetic VMH→AHA stimulation, we combined optogenetic stimulation with positron emission tomography (PET)-based metabolic mapping. This approach revealed the amygdala as a downstream area activated by the stimulation of this pathway. Our findings show that the rise and fall of AHA neuronal activ...

Visual information emerging from the extrafoveal locations is important for visual search, saccadic eye movement control, and spatial attention allocation. Our everyday sensory experience with visual object categories varies across different parts of the visual field which may result in location-contingent variations in visual object recognition. We used a body, animal body, and chair two-forced choice object category recognition task to investigate this possibility. Animal body and chair images with various levels of visual ambiguity were presented at the fovea and different extrafoveal locations across the vertical and horizontal meridians. We found heterogeneous body and chair category recognition across the visual field. Specifically, while the recognition performance of the body and chair presented at the fovea were similar, it varied across different extrafoveal locations. The largest difference was observed when the body and chair images were presented at the lower-left and upper-right visual fields...

In the article “Short-Term Synaptic Plasticity Makes Neurons Sensitive to the Distribution of Presynaptic Population Firing Rates,” by Luiz Tauffer and Arvind Kumar, which was published online …

Status epilepticus (SE) links to high mortality and morbidity. Considering the neuroprotective property of baicalein (BA), we investigated its effects on post-SE neuronal injury via the NLRP3/GSDMD pathway. Mice were subjected to SE modeling and BA interference, with seizure severity and learning and memory abilities evaluated. The histological changes, neurological injury and neuron-specific enolase (NSE)-positive cell number in hippocampal CA1 region, and cell death were assessed. Levels of the NOD-, LRR-, and pyrin domain-containing 3 (NLRP3)/gasdermin-D (GSDMD) pathway-related proteins, inflammatory factors, and Iba-1 + NLRP3+ and Iba-1 + GSDMD-N+ cells were determined. BA ameliorated post-SE cognitive dysfunction and neuronal injury in mice, as evidenced by shortened escape latency, increased number of crossing the target quadrant within 60 s and the time staying in the target quadrant, alleviated hippocampal damage, increased viable cell number, decreased neuronal injury, and increased NSE-positive c...

Throughout the primate visual cortex, individual neurons and clusters of neurons respond quite strongly to specific features within a viewed image.

The symptoms characterizing Alzheimer’s disease — memory loss and general cognitive decline — appear to derive from physical changes within the brain including amyloid plaque accumulation in the extracellular spaces, tangled fibrils of tau proteins within neural cells, and gross atrophy.

You may have heard terms such reproducibility, rigor, reliability, and robustness being increasingly used by SfN, the scientific community at large, journalists, and policymakers.