In this project, we will train mice to self-stimulate their direct pathway medium spiny neurons (dMSNs) using optogenetics. In prior work, we have found that mice find this behavior highly reinforcing. However, prior work gave mice at most 90 minutes of total training time. We plan to expand this by a factor of 100, giving the mice much more experience with this highly reinforcing behavior. We will examine behavioral changes in these mice, including assaying their motivation to receive stimulation, willingness to work for stimulation, and willingness to endure negative consequences to receive stimulation.

Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Zip Code
Krashes, Michael J; Kravitz, Alexxai V (2014) Optogenetic and chemogenetic insights into the food addiction hypothesis. Front Behav Neurosci 8:57
Friend, Danielle M; Kravitz, Alexxai V (2014) Working together: basal ganglia pathways in action selection. Trends Neurosci 37:301-3
Francis, T Chase; Chandra, Ramesh; Friend, Danielle M et al. (2014) Nucleus Accumbens Medium Spiny Neuron Subtypes Mediate Depression-Related Outcomes to Social Defeat Stress. Biol Psychiatry :
Kravitz, Alexxai V; Owen, Scott F; Kreitzer, Anatol C (2013) Optogenetic identification of striatal projection neuron subtypes during in vivo recordings. Brain Res 1511:21-32
Kravitz, Alexxai V; Tye, Lynne D; Kreitzer, Anatol C (2012) Distinct roles for direct and indirect pathway striatal neurons in reinforcement. Nat Neurosci 15:816-8
Kravitz, Alexxai V; Kreitzer, Anatol C (2012) Striatal mechanisms underlying movement, reinforcement, and punishment. Physiology (Bethesda) 27:167-77