Pharmacology of the orienting response

Lesions of the DL frontal cortex modulate the locus ceruleus (LC) and the DLF may be the only cortical afferent to the LC. Clonidine enhances anterograde memory in Korsakoff's patients. Suppression of LC firing suppresses background cortical activity, enhancing stimulus evoked activity, enhancing the signal to noise ratio. The LC is activated by novel stimuli. Lesions of the PFC inhibit attentional switching by impairing afferents to the LC. Clonidine or ritalin, that activate prefrontal cortex through the LC should improve attentional function.