CONICET | Buscador de Institutos y Recursos Humanos

Theselection and the appropriate execution of sequences of movements isessential to survival. Striatal activity has been shown to signal theinitiation and termination of behavior and it is also involved in theselection of future actions. Here we studied the neuronal activity ofthe dorsal striatum of adult rats that were trained to obtain waterby emitting a sequence of 8 licks following a visual cue. Trials wereself-initiated by the animal by entering into the nose-poke followinga 2.5 s inter-trial interval (ITI). We found a modulation of theneuronal activity related to different events in the task such as thethe execution of the action sequence, reward delivery and at theboundaries of the trials (nosepoke entry and exit). In particular,firing rate modulation previous to the beginning of the trials waslarger for longer waiting times. This anticipatory activity did notmerely reflect elapsed time nor the motor plan to be executed so, toassess if it was related to reward expectancy, rats were trained toinitiate trials in a restricted time-window (ITI 2.5-5s). Resultsshow that activity modulation for long waiting times differedbetween both versions of the task: when the ITI was long and had noreward associated to it, the amplitude of the modulation decayed,whereas rewarded long ITIs had an increasing anticipatory activity.We hypothesize this striatal activity reflects the animals´subjective valuation of timing and is key for the timely execution ofactions. p { margin-bottom: 2.12mm; direction: ltr; color: rgb(0, 0, 0); background: transparent none repeat scroll 0% 0%; }p.western { font-family: "Times New Roman", serif; font-size: 12pt; }p.cjk { font-family: "SimSun", "宋体"; font-size: 12pt; }p.ctl { font-family: "Lucida Sans", sans-serif; font-size: 12pt; }