The dosolateral/lateral (DL/L-) and ventrolateral (VL-) columns of the periaqueductal grey (PAG) coordinate respectively ‘active’ versus ‘passive’ coping strategies, which include alterations in sensory and autonomic functions that are associated with characteristic behavioural responses (Lovick & Bandler, 2005). It is well established that descending control from the PAG acts at the level of the spinal cord to modulate sensory processing and autonomic outflow. In contrast, the pathways that control motor activity are less well understood. The aim of this study was to investigate the anatomical organisation of efferent pathways from DL/L- and VL-PAG to two key pre-cerebellar structures involved in relaying hindlimb signals to the cerebellum: the rostrolateral dorsal accessory olive (IO) and the gracile nucleus (GN). Male Wistar rats (n=8, 275-350g) were anaesthetised (Ketamine 60mg.kg-1/Medetomidine 25µg.kg^-1 i.p.) and injected stereotaxically into the IO (n=7) and/or GN (n=8) with mixtures of anterograde (fluoro-ruby or fluoro-emerald) and retrograde tracers (red or green fluorescent latex microspheres). In all but 1 case, successful injections were made into both sites in the same animal. After 5-7 days survival, animals were terminally anaesthetised (propofol, 30mg.kg.h^-1 i.v.), perfusion fixed, and brains and dorsal root ganglia (DRG) removed for histological processing. In 40μm sections, injection sites in the medulla and retrogradely labelled neurones in the PAG, and in L5 DRG were mapped with a fluorescence microscope and plotted onto representative transverse sections. Anterograde terminal labelling in the cerebellum and retrogradely labelled neurones in the DRG were used to confirm the position of injection sites in IO and GN respectively. In the same animal, injections into IO resulted in a significantly higher number of labelled cells, as compared to GN (olive=80±10; gracile=20±6; mean±SEM; t-test, p<0.0001). IO injections resulted in labelled neurones throughout the PAG with significantly more in the DL/L-PAG as opposed to VL-PAG (t-test, p<0.01). Additionally, significantly more labelled neurones were identified in caudal PAG compared to rostral PAG (caudal=108±8; rostral=53±4; mean±SEM; t-test, p<0.01). The current data raise the possibility that neurones in the PAG may modify motor behaviour by modulating olivocerebellar (climbing fibre) pathways. That columnar (including rostrocaudal) differences in the organisation of these projections may underlie the different motor responses co-ordinated by the PAG requires further investigation.