\Data type and description: event-time stamp data. The time at which each event occurred (Y matrix, values 1-4) was stamped with a 10 ms resolution (Z matrix, centiseconds). Y matrix: 1=active response; 2=inactive response; 3=delivered pellet; 4=Magazine entry (time-controlled; consecutive entries within 200ms are not repeatedly stamped). Data were obtained through MED STATE NOTATION (MED Associates) and organized through MATLAB.
Steps to reproduce
\Experiment summary: 8 Aged (A1-8; 20-22 months old) and 8 Young (Y1-8; 2-3 months old) mice (C57BL6) were submitted to instrumental training (increasing random ratio schedule of reinfocement). CRF (days 1-3): constant reinforcement; RR5 (days 4-6): random ratio 5; RR10 (days 7-12): random ratio 10; RR20 (days 13-17): random ratio 20. Active lever counterbalanced (Left [L] or Right [R]). \Penalising regime: from day 10 of training, a penalizing protocol was introduced (pen5). From day 13, this regime was increased to pen7. Pen5: If the last 5 actions are not LP, probability of reward delivery is reseted; Pen7: If the last 7 actions are not LP, probability of reward delivery is reseted. \Test: on Day 18, exercise was the same as Day 17, pellets were not limited. After 20 minutes, behaving mice were rapidly anaesthetised and intracardiacally perfused (see methods)