Aggressive behaviour and physiological responses to pheromones are strongly impaired in mice deficient for the olfactory G-protein -subunit G8.

Heterotrimeric G-proteins are critical players in the transduction mechanisms underlying odorant and pheromonal signalling. In the vomeronasal organ (VNO) of the adult mouse, two different G-protein complexes have been identified. Gαoβ2γ8 is preferentially expressed in the basal neurons and coexpresses with type-2 vomeronasal pheromone receptors (V2Rs) whereas Gαi2β2γ2 is found in the apical neurons and coexpresses with type-1 vomeronasal pheromone receptors (V1Rs).

Projections to the superior colliculus from inferior parietal, ventral premotor, and ventrolateral prefrontal areas involved in controlling goal-directed hand actions in the macaque.

We found that the macaque inferior parietal (PFG and anterior intraparietal [AIP]), ventral premotor (F5p and F5a), and ventrolateral prefrontal (rostral 46vc and intermediate 12r) areas forming a network involved in controlling purposeful hand actions ("lateral grasping network") are a source of corticotectal projections. Based on injections of anterograde tracers at the cortical level, the results showed that all these areas displayed relatively dense projections to the intermediate and deep gray layers of the ipsilateral superior colliculus (SC) and to the ventrally adjacent mesencephalic reticular formation. In the SC, the labeling tended to be richer in the lateral part along almost the entire rostro-caudal extent, that is, in regions controlling microsaccades and downward gaze shifts and hosting arm-related neurons and neurons modulated by the contact of the hand with the target.

Connectional heterogeneity of the ventral part of the macaque area 46.

We found that the ventral part of the prefrontal area 46 (46v) is connectionally heterogeneous. Specifically, the rostral part (46vr) displayed an almost exclusive and extensive intraprefrontal connectivity and extraprefrontal connections limited to area 24 and inferotemporal areas. In contrast, the caudal part (46vc) mostly displayed intraprefrontal connectivity with ventrolateral areas and robust connectivity with frontal and parietal sensorimotor areas.

Neuropeptide Y in the olfactory microvillar cells.

This paper examines a possible role of microvillar cells in coordinating cell death and regeneration of olfactory epithelial neurons. The olfactory neuroepithelium of mammals is a highly dynamic organ. Olfactory neurons periodically degenerate by apoptosis and as a consequence of chemical or physical damage.