Sonic/vocal-acousticolateralis pathways in teleost fishes: A transneuronal biocytin study in mochokid catfish

Abstract

Mochokid catfish have two sound producing (sonic) organs--a pectoral spine stridulatory apparatus and a swimbladder whose vibration is established by nearby "drumming" muscles. Dextran-biotin or biocytin application to sonic nerves or muscles identified topographically separated motoneuron pools. Pectoral spine-related motoneurons are located within the ventral motor column whereas swimbladder motoneurons lie just ventral to the central canal or fourth ventricle. Axons of both groups of motoneurons exit the brain and spinal cord via ventral roots of occipital (swimbladder and pectoral) and spinal (swimbladder only) nerves. Transneuronal biocytin transport identified an extensive premotor network only for the swimbladder motor nuclei. Premotoneuron somata are located ipsilaterally in 1) a dorsolateral region of the sonic motor nucleus (SMN); motoneurons were clustered in the ventromedial region of the SMN and 2) the ventromedial medulla at the rostral pole of the SMN. Biocytin-filled fibers and less frequently premotoneuron somata were also found in the contralateral SMN. Biocytin-labeled fibers were continuous farther rostrally with 1) a commissural bundle that terminated bilaterally in the medial reticular formation near the caudal pole of the descending octaval nucleus and 2) a lateral brainstem bundle that terminated ipsilaterally in regions of the medulla and cerebellum considered to subserve acoustic and lateral line functions. Together with other data in distantly related teleost fishes, the results support the hypotheses that 1) central pathways linking sound-generating (sonic or vocal) and acoustic regions of the brain are traits common to both teleosts fishes and tetrapods that actively generate sounds, and 2) sonic/vocal pathways in teleosts have a conserved pattern of organization suggestive of common developmental origins.

Sound‐generating and ‐detecting motor system in catfish: Design of swimbladder muscles in doradids and pimelodids

“…Fine et al (1990) showed that fiber diameters increased as the oyster toadfish Opsanus tau grows. Mochokid catfishes, which are closely related to doradids-both constitute the taxon "doradoids" (Lundberg, 1993)-possess a very similar contractile cylinder and are similar in fiber diameter (20 vs. 16 m in Platydoras) (Hagedorn et al, 1990; for a discussion of the sonic/electric muscle in Synodontis, see Ladich and Bass, 1996). Because Pimelodus differs from Platydoras in organelle arrangement and in several other morphometrical measures (larger muscle fiber diameter, larger myofibril volume density) a typical "catfish pattern" of sonic muscle fiber organization does not exist.…”

Morphology of the gas bladder in bumblebee catfishes (Siluriformes, Pseudopimelodidae)

“…The muscles inserted directly on the gas bladder wall are herein designated constrictor muscles, following Lundberg and Akama (2005: 498). These muscles were previously called drumming muscles (Ladich,2001), sonic muscles (Ladich and Bass,1996) or compressor muscles (Bridge and Haddon,1893: 115; Stewart,1986: 664).…”

Sound Communication in Fishes

“…3). See Wiley and Johnson (2010), Betancur-R et al (2013) and Broughton et al (2013) for teleost classification in Tables 2.1 and 2.2 a ; b Ladich and Bass (2005); c Onuki et al (2006); d Ladich and Bass (1998); e Ladich and Bass (1996); f ; g ; h Onuki et al (2010); i Bennett and Pappas (1965); j Fine et al (1982); k ; l Fine and Mosca (1989); m Bass and Baker (1997); n Bass and Baker (1990); o Yoshimoto et al (1999);p Finger and Kalil (1985); q Fine 2006), as it is among birds (Prum 1998;Hingee and Magrath 2009;Miller and Baker 2009;Bostwick et al 2010;Barske et al 2011) andmammals (Reynolds 1965;Remedios et al 2009). References corresponding to superscript alphabets are found below (also see for references on sonic organ).…”

“…Vocal premotoneurons directly within, adjacent to, or rostral to VMN have also been identified by transneuronal biotin transport in catfish (Mochokidae, Table 2.1) (Ladich and Bass 1996), squirrelfish (Holocentridae, Table 2.1) and rockfish (Scorpaenidae, Table 2.1) (Yoshimoto et al 1999). For these groups of fish, as in midshipman and toadfish Chagnaud and Bass 2014), biocytin or neurobiotin labeling also showed connections between the vocal system and the central auditory system, including the octavolateralis efferent nucleus (OEN) that directly innervates the inner ear and lateral line organs.…”