Dynamic encoding of saccade sequences in primate frontal eye field

AO_SCPLOWBSTRACTC_SCPLOWFrontal eye field (FEF) is a key part of oculomotor system, with dominant responses to the direction of single saccades. However, whether and how FEF contributes to sequential saccades remain largely unknown. Here by training rhesus monkeys to perform sequential saccades and recording the neuronal activities in FEF, we found that the sequence-related activities are clearly represented in FEF, and many neurons selectivity to saccade direction undergoes dynamic changes during sequential task. In addition, the sequence-related activities are context-dependent, with different firing activities during memory- versus visually-guided sequence. Supra-threshold microstimulation in FEF evokes saccade without altering the overall sequence structure. Pharmacological inactivation of FEF severely impaired the monkeys performance of sequential saccades, with different effects on the same actions at different positions within the sequence. These results reveal the context-dependent dynamic encoding of saccade direction in FEF, and underscore a critical role of FEF in planning and execution of sequential saccades. IO_SCPLOWNC_SCPLOW BO_SCPLOWRIEFC_SCPLOWJia, Puyang et al. employed in vivo recording to reveal the dynamic encoding of sequential saccades in primate frontal eye field (FEF), then used electric microstimulation and reversible inactivation to demonstrate the causal role of FEF in controlling saccade sequences. HO_SCPLOWIGHLIGHTSC_SCPLOWO_LIFEF neurons respond differently during sequential vs. single saccades C_LIO_LISequence-related FEF activity is context-dependent C_LIO_LIFEF microstimulation induced saccade without altering sequence structure C_LIO_LIFEF inactivation severely impaired the performance of sequential saccades C_LI