Positive reinforcement-based magnet training permits social housing in catheterized squirrel monkeys.

Background: Non-human primates play a critical role in neuroscience research. Though they are social animals, laboratory study requirements can sometimes require single housing and thereby prevent social housing.

New Method: To eliminate single housing and promote well-being within our squirrel monkey colony, we used positive reinforcement training in combination with magnetic/mechanical clasps and custom jackets to permit pair housing of catheterized squirrel monkeys used in behavioral studies.

Expression of the excitatory opsin ChRERα can be traced longitudinally in rat and nonhuman primate brains with PET imaging.

Optogenetics is a widely used technology with potential for translational research. A critical component of such applications is the ability to track the location of the transduced opsin in vivo. To address this problem, we engineered an excitatory opsin, ChRERα (hChR2(134R)-V5-ERα-LBD), that could be visualized using positron emission tomography (PET) imaging in a noninvasive, longitudinal, and quantitative manner.

Effects of buprenorphine, methadone, and cariprazine on economic choice between remifentanil and food in squirrel monkeys.

We recently reported an economic choice task in which squirrel monkeys chose between differing amounts of remifentanil, a fast-acting opioid, or a food reward to develop a preclinical screen for evaluating potential pharmacotherapies for opioid dependence. Herein, two known opioid addiction treatments are evaluated using this task, as well as a potential new agent, cariprazine, a dopamine D2/D3 receptor partial agonist currently used to treat bipolar disorder and schizophrenia. Preclinical rodent studies suggest this class of compounds may reduce opiate self-administration.

Reinforcement learning modeling reveals a reward-history-dependent strategy underlying reversal learning in squirrel monkeys.

Insight into psychiatric disease and development of therapeutics relies on behavioral tasks that study similar cognitive constructs in multiple species. The reversal learning task is one popular paradigm that probes flexible behavior, aberrations of which are thought to be important in a number of disease states. Despite widespread use, there is a need for a high-throughput primate model that can bridge the genetic, anatomic, and behavioral gap between rodents and humans.

Deliberative Decision-Making in Macaques Removes Reward-Driven Response Vigor.

Most of our daily decisions are governed by one of two systems: an impulsive system driving instantaneous decisions and a deliberative system driving thoughtful ones. The impulsive system reacts to immediately available concrete rewards. In contrast, the deliberative system reacts to more delayed rewards and/or punishments, which imposes consideration of longer-term choice consequences.