RT Journal Article
SR Electronic
T1 The Role of the Monkey Dorsal Pontine Nuclei in Goal-Directed Eye and Hand Movements
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 6154
OP 6166
DO 10.1523/JNEUROSCI.0581-09.2009
VO 29
IS 19
A1 Konstantin Tziridis
A1 Peter W. Dicke
A1 Peter Thier
YR 2009
UL http://www.jneurosci.org/content/29/19/6154.abstract
AB Prevailing concepts on the control of goal-directed hand movements (HM) have focused on a network of cortical areas whose early parieto-occipital stages are thought to extract and integrate information on target and hand location, involving subsequent stages in frontal cortex forming and executing movement plans. The substantial experimental results supporting this “cortical network” concept for hand movements notwithstanding, the concept clearly needs refinement to account for the surprisingly mild HM disturbances resulting from disconnecting the parieto-occipital from the frontal stages of the network. Clinical observations have suggested the cerebropontocerebellar projection as an alternative pathway for the sensory guidance of HM. As a first step in assessing its role, we explored the pontine nuclei (PN) of rhesus monkeys, trained to make goal-directed hand and eye movements guided by spatial memory. We were indeed able to delineate a distinct cluster of neurons in the rostrodorsal PN, activated by the preparation and the execution of hand reaches, close to but distinct from the region in which saccade-related neurons may be observed. The movement-related activity of HM-related neurons starts earlier than that of saccade-related neurons and both neuron types are usually effector specific, i.e., they respond only to the movement of the preferred effector. This is also the case when motor synergies involving both effectors are executed. Our findings support the notion of a distinct precerebellar, pontine visuomotor channel for hand reaches that is anatomically and functionally largely separated from the one serving eye movements.