The Arecibo Observatory has a unique instrument cluster to measure simultaneously ion layers (Sporadic-E and descending layers) along with neutral metal layers, using incoherent scatter radar (ISR) and resonance lidars respectively. The Arecibo data set presents excellent opportunities to investigate the role of ion-neutral coupling, and the connection between tidal ion layers and thermospheric metal layers. The origin of the latter is still a subject of considerable interest, and it can be further understood through simultaneous observations of ionized and neutral species. In this paper, we will present case studies, through which we expect to reveal clearer insights about metal layers at thermospheric altitudes and how these will guide our future endeavors. This study will focus on

(a) an example of thermospheric neutral layers in Na and K along with electron density data showing no correlation between them. Some additional examples revealing descending layers in ISR data over Arecibo but lacking of neutral layers also suggest that neutralization of metal ions could not be the source of metals at altitudes higher than the meteor ablation zone, and

(b) neutral Sporadic layers observed in Na (Na_S) and Fe (Fe_S) along with their relationship to Sporadic E (E_S) as seen in ISR data will also be discussed.

Such studies highlight the significance of making multi-metal observations and also suggest the importance of implementing the capability that will allow Fe measurements using narrowband Alexandrite laser in the future.