The ventral nucleus of the lateral lemniscus of the gerbil (Meriones unguiculatus): Organization of connections with the cochlear nucleus and the inferior colliculus

Abstract

The spatial organization of projections from the ventral cochlear nucleus (VCN) to the ventral nucleus of the lateral lemniscus (VNLL) and from the VNLL to the central nucleus of the inferior colliculus (CNIC) was investigated using neuroanatomical tracing methods in the gerbil. In order to label cells in the VNLL that project to the CNIC, focal injections of biotinylated dextran amine (BDA) were made into different CNIC regions. Retrogradely labeled cells were distributed throughout the dorsal-to-ventral axis of the VNLL in all cases. In contrast, the distribution of labeled cells across the lateral-to-medial dimension of the VNLL was related to the location of the injection site along the dorsolateral to ventromedial (frequency) axis of the CNIC. Cells projecting to dorsolateral (low-frequency) regions of the CNIC were located peripherally in the VNLL, mainly laterally and caudally, whereas those projecting to ventromedial (high-frequency) regions of the CNIC tended to be clustered centrally. Projections to the VNLL were labeled anterogradely following injections of BDA in the VCN. The distribution of terminal fields in the VNLL closely paralleled the topographic arrangement of cells projecting to the CNIC; projections from ventrolateral (low-frequency) areas of the VCN terminated mainly along the lateral and caudal borders of the VNLL, whereas projections from dorsomedial (high-frequency) areas terminated in more central regions. The results demonstrate a topographic organization of the major afferent and efferent connections of the gerbil VNLL.

Connections of the auditory brainstem in a songbird, Taeniopygia guttata. III. Projections of the superior olive and lateral lemniscal nuclei

“…One significant point of similarity between mammalian and avian auditory brainstem pathways, however, is the massive input from LLV and VNLL to the IC of birds and mammals, respectively (e.g., Benson and Cant, 2008; present results). In mammals this input is a major source of both GABAergic and glycinergic inhibition on the IC (Schofield, 2005).…”

“…obs.). VNLL neurons are thought to be involved in the recognition of temporal patterns and the processing of complex sounds (Benson and Cant, 2008). If LLV neurons in birds have similar functional attributes, and if these attributes are conveyed to the ICc by way of inhibitory signals, they could possibly contribute to the processing of complex auditory stimuli, such as that involved in feature extraction and the recognition of conspecific song (Woolley and Casseday, 2004, 2005; Logerot et al, 2009).…”

Connections of the auditory brainstem in a songbird, Taeniopygia guttata. II. Projections of nucleus angularis and nucleus laminaris to the superior olive and lateral lemniscal nuclei

“…Since then there has been a host of studies in a variety of species dealing with the projections of the cochlear nuclei to one or more of the superior olivary nuclei and/or the three lateral lemniscal nuclei (e.g., Friauf and Ostwald, 1988; Kuwabara et al, 1991; Smith et al, 1991, 1993; Huffman and Covey, 1995; Schofield, 1995; Schofield and Cant, 1997; Adams, 1997; Glendenning and Hutson, 1998; Thompson and Schofield, 2000; Doucet and Ryugo, 2003), findings from these and other studies having been extensively reviewed (Schwartz 1992; Helfert and Aschoff, 1997; Oertel and Wickesberg, 2002; Cant and Benson, 2003; Schofield, 2005; Benson and Cant, 2008). …”

Behavioral evidence for auditory induction in a species of rodent: Mongolian gerbil (Meriones unguiculatus)

“…To these ends, we chose a small desert rodent, the Mongolian gerbil, as the subject species (Thiessen and Yahr, 1977). This species has been an important model for auditory physiology (for review, e.g., Scheich, 1991;Budinger and Scheich, 2009); thus, the properties of the neuronal activities and the circuitry of the auditory system have been well researched (Ryan et al, 1982;Sanes et al, 1989;Heil and Scheich, 1991a;1991b;Thomas et al, 1993;Bruckner and Rubsamen, 1995;Budinger et al, 2000a;2000b;Cant and Benson, 2006;Benson and Cant, 2008). Whereas the studies using communication signal have provided evidences of the auditory induction in several animals (Braaten and Leary, 1999;Miller et al, 2001;Seeba and Klump, 2009), we used the tone burst as stimulus.…”