Sneha Rao (Gogos Lab)

Patient-derived cerebral organoids as a model system for the 22q11.2 deletion syndrome

Adults and children with the 22q11.2 deletion syndrome (22q11.2DS) demonstrate cognitive, social and emotional impairments. 22q11.2 deletions are also one of the strongest genetic risk factors for schizophrenia (SCZ). While mouse models have provided important mechanistic insights, the effects of the deletion on human neuronal development remain largely unaddressed. We aim to characterize the 22q11.2DS in human iPSC-derived cerebral organoids. Cerebral organoids recapitulate human embryonic brain development in vitro and could also serve as a useful system to test therapeutic strategies. Using this patient-derived system, we are characterizing the effects of 22q11.2 deletions on human neuronal development, function as well as local and global connectivity.

Natalie Steinemann (Shadlen Lab)

Single-trial measures of decision making in macaque parietal cortex

When evaluating noisy stimuli, decision speed and accuracy can be optimized by sampling evidence repeatedly and integrating samples until a decision threshold is reached. Neural correlates of this process have been observed experimentally in areas LIP and MIP in macaques, but only when combining data across many trials. Using novel, high-channel count electrodes we record simultaneously from an unprecedented number of neurons and show, for the first time, that unfolding decisions can be observed directly in the population activity, allowing us to predict choice and response time at the single-trial level. By varying the way in which animals reported their choices, we further showed that distinct neural subpopulations in LIP and MIP relate to the deliberation and choice processes in different, sometimes unexpected ways.