PROJECT SUMMARY The choroid plexus (ChP) comprises a network of cells that form a critical brain barrier that can mediate secondary damage in certain brain disorders and trauma. The Lehtinen lab has developed a suite of tools to study the ChP across development ex vivo and in vivo. This project applies imaging technology to study blood- CSF barrier permeability regulation at the cellular level.
Project Summary: The majority of lived experience depends on neural activity conveying sensory information about the world. Neural trauma and stroke are leading causes of disorders such as coma and spatial neglect, which severely damage visual experience, and there are no viable treatment options. Similarly, life saving medical treatments depend on the ability for general anesthesia to temporarily disconnect patients from the sensory world. Current anesthetics do so by inhibiting the entire brain, including the brainstem, which is a significant health risk.
PROJECT SUMMARY / ABSTRACT Persistent activity in neural circuits supports a variety of brain functions from motor control to navigation to perceptual decision-making. Correlational studies show significant variation in persistent activity patterns during different behaviors, suggesting that individual circuits perform flexible computations that depend on the context of ongoing brain activity and motor functioning. However, establishing the causal significance of this variability is difficult due to technical limitations in existing tools for precisely manipulating circuit dynamics.
Project Summary / Abstract Increased mammalian target of rapamycin (mTOR) signaling is a known cause of treatment resistant epilepsy. Pathological mutations to negative regulators of mTOR lead to hyperactive mTOR signaling and have been found in the forebrain and cerebellum of individuals with epilepsy. The cerebellum has recently been shown to contribute to the development of epilepsy. However, research in hyperactive mTOR induced epilepsy has almost exclusively been focused on the hypothalamus and forebrain structures.
Changes in the strength of GABAergic transmission is heavily influenced by posttranslational modifications and allosteric modulators like benzodiazepines and neurosteroids. O-GlcNAcylation (O- GlcNAc) is a post- translational modification that is tightly regulated by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which add or remove the O-GlcNAc moiety of β–N-acetylglucosamine to Ser/Thr residues on proteins, respectively. Various neurodegenerative diseases like Alzheimer's disease (AD), and metabolic disorders like, diabetes exhibit dysregulated O-GlcNAc levels.
Project Summary Schizophrenia is a debilitating mental illness affecting an estimated 1% of the global population. Substance abuse comorbidity is common in a number of mental illnesses, including post-traumatic stress disorder, bipolar disorder, and schizophrenia, with nicotine being the most commonly abused substance. This comorbidity has several detrimental effects, including reduced quality of life and reduced efficacy of treatment.
Project Summary Sub-Cerebral Projection Neurons (SCPNs) are a clinically relevant neuron class that controls voluntary movement and whose loss in Amyotrophic Lateral Sclerosis and Fronto-temporal dementia or injury (e.g., damaged by spinal cord injury) leads to paralysis. Currently, there are no methods to replenish injured or lesioned SCPNs. A milestone in regenerative medicine is to utilize cellular reprogramming for brain and circuit repair. This approach uses developmental genes and identity maintenance pathways to switch one cell type to another to replenish vulnerable neuron types.
In natural vision, recognizing objects based on the retinal image is challenging and is often an ill-posed problem because a single image is compatible with multiple interpretations. Nevertheless, the primate brain has a remarkable ability to understand ambiguous scenes and solve difficult object recognition problems. Converging evidence suggests that this process, especially in challenging contexts—e.g., occlusion or low-visibility environments—is based on the integration of sensory information with prior knowledge built from experience.
PROJECT SUMMARY/ABSTRACT An important longstanding goal in neuroscience research is to understand how large-scale spatiotemporal patterns of neural activity emerge in the brain and whether they have a direct role in shaping the brain’s computational processes and thereby mammalian behavior.
SUMMARY Norepinephrine (NE) is a neurotransmitter released by a small number of neurons in the locus coeruleus (LC), with extensive innervation of the neocortex. Prior work in humans and other mammals led to the hypothesis that LC-NE neurons modulate multiple forms of decision making. This proposal aims to test this overall hypothesis by studying LC-NE neurons in mice performing multiple decision-making tasks.
