Training

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.

PROJECT SUMMARY/ABSTRACT Parental care is essential for offspring well-being and survival yet requires a significant invest from adults without immediate benefit, suggesting the existence of hard-wired mechanisms governing its control. Despite the importance of this evolutionarily controlled behavior, parental behaviors vary greatly between animals of different sex, physiological state, and genetic background.

PROJECT SUMMARY/ABSTRACT Humans have highly advanced cognitive abilities and motor skills, characteristics which are reflected in the enlarged size and cell diversity of our central nervous system (CNS). My overall goal is to profile and compare progenitor cell diversity in humans, non-human primates and rodents, and thereby identify the origins of increased cell diversity and size of the human CNS.

PROJECT SUMMARY The world around us has a statistical structure that we can use to improve our choices. Learning the underlying structure by identifying key features, such as the rate of change, is useful for adapting and optimizing our decision-making strategies. However, learning these features requires accumulating evidence across multiple timescales: a short timescale that considers explicit evidence for the current decision, and a long timescale that supports latent environmental feature inference.

PROJECT SUMMARY / ABSTRACT. Research Project: Spatial memory – memory of where an event happened or an object was located – depends on the hippocampus in a wide range of vertebrate species, including mammals and birds. In humans, most spatial memories are formed through visual experience. However, it is unclear how visual information is processed by hippocampal memory circuits to support spatial memory formation.

This proposal describes a five-year career development program to prepare the candidate, Dr. Nan Xu, for a career as independent investigator at a major academic research institute, with the expertise of modeling dynamics of brain causal system to provide novel insights into the basic pathophysiology of neurologic disorders. This proposal develops upon Dr.

Project Summary Intracortical microstimulation (ICMS) of the sensory cortices is an emerging approach to restore sensation to people who have lost it due to neurological injury or disease. ICMS of somatosensory cortex has been used in clinical trials to restore sensation to the hands of people with spinal cord injury and, more recently, was used to restore vision to a person with blindness. The sensations evoked by ICMS are dependent on the stimulated electrode and selected parameters.

Abstract Microelectrode arrays (MEAs) have great potential for therapeutic use in direct brain-computer interface (BCI) control of robotic prostheses to improve the lives of patients suffering from debilitating conditions related to loss of limbs or limb function. MEAs also have the potential to restore loss of sensory perception in vision, hearing, and tactile sensation by applying patterned current stimulation to sensory neurons.

Project Summary Learning and performing complex skills such as speech or music requires precise control of motor variability. While elevated motor variability can spur the learning of new behaviors, excessive variability can impair performance of learned skills. How the brain controls motor variability during learning and in expert performance remains unclear. Intriguingly, the basal ganglia (BG) is an important source of motor variability in both health and disease, and is a key site where dopamine (DA) reinforces more successful behaviors.

Decision making is a fundamental cognitive process, and many decisions are based on gradually accumulated evidence. Thus, it is critical to understand the mechanistic basis underlying this accumulation process. Traditional models of evidence accumulation are based on low-dimensional attractors where individual neurons show ramping activity throughout a trial. However, an increasing number of studies have observed choice-selective sequences in their neural recordings, in which neurons fire transiently and sequentially with the subset of neurons that fires indicative of the animal’s choice.