This MS is entirely relevant to the aims and scope of the EJN, complies with the author guidelines and is work of high technical quality. The key findings are …

(i) That single neuron activity in the PPTg is associate with skilled forelimb use. This is a significant advance on the repeated association of the PPTg with whole body locomotion.
(ii) That single PPTg neurons are activated by both skilled forelimb use and auditory stimulation. This is a very significant finding. There has been a lot of effort to examine sensory and motor functions of the PPTg in terms of region – compacta/dissipata or anterior/posterior PPTg – or by neuronal neurochemical identity, cholinergic/non-cholinergic. To find sensory and motor activity present in single neurons is a significant step forward, emphasising the integrative functions of this nucleus.
(iii) That there is theta activity during performance of the reaching and grasping task. This is interesting and well-worth reporting, but not a massive surprise. It does however reinforce the idea that the PPTg is important in sophisticated movement control.
(iv) That raclopride induced catalepsy changes PPTg activity, depressing neuron firing rates and increasing regularity.

The data showing PPTg activity in relation to skilled movements rather than whole body locomotion are important but was perhaps predictable from some of the behavioral literature. It’s excellent to have this demonstrated but the most significant advance is the discovery of sensory and motor properties of single neurons. It is consistent with work elsewhere – the authors cite instances relating to motor control: motor cortex, basal ganglia, red nucleus – but work across much of the neocortex is showing neurons activated by both sensation and active behavior. (Check the work from Kenneth Harris’s lab at UCL.) This is a real addition to our understanding of the PPTg.

The theta oscillation data is interesting and consistent with a role for the PPTg in the execution of skilled tasks. It’s always nice when something unexpected is spotted in the data. On the other hand, I’m not wholly sure what the raclopride data are doing for the MS. The information doesn’t detract in any way, but I can’t really see how it adds to our understanding of PD or the PPTg – and it’s a stretch to call this acute parkinsonian akinesia because the similarity to PD is only in the paucity of movement. Switching between acute parkinsonian akinesia and catalepsy isn't right either. If the raclopride data are retained an appropriate and consistent approach should be taken to describing its effects.

Overall, I think this is a really good MS with interesting new data. The work is technically sophisticated, with well-established methodologies. It’s very clearly written and presented, other than the very tiniest typo. Sometimes it’s PPTg, but just occasionally the last g gets capitalized to PPTG (on pages 3, 12 & 18). For the PPTg enthusiast, it really jumps out.