Intracellular activity and morphology of the prefrontal neurons related to visual attention task in behaving monkeys

Neurons of the prefrontal-premotor cortex, which had been studied electorophysiologically during a modified reaction time task, were identified by intracellular pressure micro-injection of horseradish peroxidase (HRP). The cells were classified into those showing a sustained vs. transient change in activity during performance of the task. Cells showing a sustained response were found to have their somata in layers III and VI and cells showing transient responses were found to have their somata in layers II and III. All cells were pyramidal cells with spiny dendrites.