text: Yo, check it out, let me break it down for ya,
  We studied tyrosine hydroxylase (TH)-immunoreactive neurons,
  In the olfactory bulb of the leopard frog, Rana pipiens,
  And in the clawed frog, Xenopus laevis, keep listenin'.
  
  In both frogs, TH processes in the main olfactory bulb,
  Showed a trilaminar organization, that's no bull,
  Densely stained external glomerular layer (GL) on the outside,
  Moderately stained middle mitral cell layer (MCL) to ride.
  
  Internally, a weakly stained internal plexiform layer (IPL),
  And granule cell layer (GRL), that's the deal,
  TH-positive cells in the MCL and IPL, two types they be,
  Let me break it down, so you can clearly see.
  
  Type 1 cells with thick dendrites arborized in the GL,
  Axon-like process exited the cell, oh, what the hell,
  A recurrent collateral that ascended into the GL,
  Type 2 cells had beaded dendrites in the MCL, oh, do tell.
  
  In Rana, both type 1 and type 2 cells were plenty,
  In the MCL and IPL, they were far from empty,
  But in Xenopus, only type 2 cells were found,
  In the MCL and IPL, holdin' it down.
  
  In the GL, labeled cells were numerous in Xenopus,
  But in Rana, they were rare, not as obvious,
  Mitral cells were stained retrogradely, you see,
  By tracer injection into the lateral olfactory tract, G.
  
  And by local injection into the bulb, that's right,
  But double labeling for TH? Nah, out of sight,
  No observation of that, so it's likely to be,
  TH-positive cells in frog olfactory bulb, interneurons, you see?
  
  Double labeling with anti-gamma-aminobutyric acid (GABA) antibody,
  Showed TH-positive cells separated, different territory,
  From the GABA-containing interneurons, distinct crew,
  That's the lowdown on the frogs, now you're all in the loop.