Fig. 6 ( a ) Schematic sagittal view of the brain showing vocal motor ( red ), and central auditory
( blue ) systems in batrachoidid fi sh (midshipman and toadfi sh) (modifi ed from Bass and McKibben
2003 ; Kittelberger et al. 2006 ) with connectivity from large TH-ir neurons within periventricular
posterior tuberculum ( green , TPp). Solid dots represent somata, and lines represent axonal projection pathways. Two connected dots indicate reciprocal connections. Descending vocal motor pathways (see Bass and Baker 1990 ; Bass et al. 2000 , 2001 ; Bass et al. 1994 ; Fine and Perini 1994 ;
Goodson and Bass 2002 ; Kittelberger et al. 2006 ; Remage-Healey and Bass 2004 ). Preoptic (POA,
not shown) and ventral (vT) and anterior (AT) tuberal nuclei in the hypothalamic forebrain project
to the periaqueductal gray (PAG) in the midbrain which then connects to the vocal pattern generator (VPG) in the hindbrain-spinal cord. The VPG consists of vocal prepacemaker (VPP), pacemaker (VPN), and motor (VMN) nuclei. The VMN projects directly via occipital nerve roots to
sound-producing muscle on the swim bladder. Central auditory system (see Bass et al. 2000 , 2001 ;
Bass et al. 1994 ). Social vocalizations are detected by the inner ear which projects via the VIIIth
nerve to descending (DO) and secondary (SO) octaval nuclei in the hindbrain and further to the
( blue ) systems in batrachoidid fi sh (midshipman and toadfi sh) (modifi ed from Bass and McKibben
2003 ; Kittelberger et al. 2006 ) with connectivity from large TH-ir neurons within periventricular
posterior tuberculum ( green , TPp). Solid dots represent somata, and lines represent axonal projection pathways. Two connected dots indicate reciprocal connections. Descending vocal motor pathways (see Bass and Baker 1990 ; Bass et al. 2000 , 2001 ; Bass et al. 1994 ; Fine and Perini 1994 ;
Goodson and Bass 2002 ; Kittelberger et al. 2006 ; Remage-Healey and Bass 2004 ). Preoptic (POA,
not shown) and ventral (vT) and anterior (AT) tuberal nuclei in the hypothalamic forebrain project
to the periaqueductal gray (PAG) in the midbrain which then connects to the vocal pattern generator (VPG) in the hindbrain-spinal cord. The VPG consists of vocal prepacemaker (VPP), pacemaker (VPN), and motor (VMN) nuclei. The VMN projects directly via occipital nerve roots to
sound-producing muscle on the swim bladder. Central auditory system (see Bass et al. 2000 , 2001 ;
Bass et al. 1994 ). Social vocalizations are detected by the inner ear which projects via the VIIIth
nerve to descending (DO) and secondary (SO) octaval nuclei in the hindbrain and further to the