Here we investigate the functional correlates of BG beta oscillations in intact, unrestrained rats. We recorded simultaneously from multiple structures to assess whether beta rhythms coordinate activity throughout the BG network. The rats performed four task variants that make different demands for behavioral control: subjects were instructed to promptly make specific movements (“Immediate-GO”), program movements but delay Cilengitide their execution (“Deferred-GO”), inhibit movements

(“NOGO”), or cancel movements-in-preparation (“STOP”). By comparing beta power time courses under each condition, we examined how dynamic states of cortical-BG circuits relate to distinct sensorimotor subprocesses. We first examined LFPs recorded from the striatum (STR), globus pallidus (GP), and primary motor cortex selleck kinase inhibitor (M1) during a choice reaction time task. Rats initiated trials by poking and holding their position within an illuminated nose-port (Figures 1A and 1B). After a variable interval, one of two instruction cues (1 kHz, 4 kHz tones) directed the rat to quickly move his nose one port to the left or right, respectively. We have previously shown that contralateral performance in this “Immediate-GO” task is dependent on intact function of sensorimotor striatum (Gage et al.,

2010). Beta oscillations (15–25 Hz) were consistently more pronounced in STR and GP compared to M1, yet in each structure beta power was similarly modulated by task events (Figure 1C). Beta power initially dipped as rats entered the first port and stayed there (Nose In). This was followed by a sharp beta increase (“event-related synchronization,” ERS) after the instruction tone (Cue/Go), which peaked just after they initiated their chosen movement (Nose Out). There was a further abrupt decrease in beta power (an “event-related desynchronization,” ERD) as rats completed this movement (Side In), which triggered

an audible food pellet delivery click on correct trials. Movement initiation is typically associated with beta ERDs, in contrast to the ERS that we observed. However, most prior studies have either used self-paced movements (Pfurtscheller et al., 2003 and Alegre et al., 2005) or imposed a delay between instruction cues and the corresponding movements (MacKay and Mendonça, Carnitine dehydrogenase 1995, Baker et al., 1997, Rubino et al., 2006, Sanes and Donoghue, 1993 and Kühn et al., 2004). We therefore examined beta power during a second task version (“Deferred-GO,” Figure 1B). In this task, subjects can use the instruction cue to prepare a movement, but to obtain reward they must delay execution until presentation of a separate “Go” signal. Information about the behavior of each rat in each task is given in Table S1 (available online). Rats trained in the Immediate-GO and Deferred-GO tasks attempted similar numbers of trials per session (averaging 173 and 160, respectively), consistent with similar levels of motivation.