Descending projections from the nucleus retroambiguus to the iliopsoas motoneuronal cell groups in the female golden hamster: Possible role in reproductive behavior

Self Cite

Vocalizations such as mews and cries in cats or crying and laughter in humans are examples of expression of emotions. These vocalizations are generated by the emotional motor system, in which the mesencephalic periaqueductal gray (PAG) plays a central role, as demonstrated by the fact that lesions in the PAG lead to complete mutism in cats, monkeys, as well as in humans. The PAG receives strong projections from higher limbic regions and from the anterior cingulate, insula, and orbitofrontal cortical areas. In turn, the PAG has strong access to the caudal medullary nucleus retroambiguus (NRA). The NRA is the only cell group that has direct access to the motoneurons involved in vocalization, i.e., the motoneuronal cell groups innervating soft palate, pharynx, and larynx as well as diaphragm, intercostal, abdominal, and pelvic floor muscles. Together they determine the intraabdominal, intrathoracic, and subglottic pressure, control of which is necessary for generating vocalization. Only humans can speak, because, via the lateral component of the volitional or somatic motor system, they are able to modulate vocalization into words and sentences. For this modulation they use their motor cortex, which, via its corticobulbar fibers, has direct access to the motoneurons innervating the muscles of face, mouth, tongue, larynx, and pharynx. In conclusion, humans generate speech by activating two motor systems. They generate vocalization by activating the prefrontal-PAG-NRA-motoneuronal pathway, and, at the same time, they modulate this vocalization into words and sentences by activating the corticobulbar fibers to the face, mouth, tongue, larynx, and pharynx motoneurons.

Section: Premotor Interneurons Generating Vocalizationmentioning

confidence: 99%

Section: Afferent Projections To the Nucleus Retroambiguusmentioning

confidence: 99%

Two different motor systems are needed to generate human speech

Holstege

Subramanian

2015

Self Cite

“…The role of NRA in respiratory control was highlighted in the early 1970s (Merrill, 1970, 1972) and thereafter became synonymous with the caudal component of the ventral respiratory group (cVGR; Feldman et al, 1985), having a particular role in the control of expiration via its predominantly contralateral spinal projections to motoneurons innervating abdominal and internal intercostal muscles. In fact, NRA appears to be involved in any behavior requiring raised intraabdominal or intrathoracic pressure (Holstege and Kuypers, 1982; Feldman et al, 1985; Miller et al, 1985, 1987, 1989; Holstege, 1989, 1991; Iscoe, 1998; Kirkwood et al, 1999) and over the past decade has also been implicated in the control of reproductive behavior by virtue of its bulbospinal projections to motoneurons innervating a variety of muscles that facilitate species-specific mating postures (Vanderhorst and Holstege, 1995, 1997a,b; Gerrits and Holstege, 1999; Gerrits et al, 2000; Vanderhorst et al, 2000b; Klop et al, 2002; Kirkwood and Ford, 2004). …”

mentioning

confidence: 99%

Avian nucleus retroambigualis: Cell types and projections to other respiratory‐vocal nuclei in the brain of the zebra finch (Taeniopygia guttata)

Wild

Kubke

Mooney

2008

In songbirds song production requires the intricate coordination of vocal and respiratory muscles under the executive influence of the telencephalon, as for speech in humans. In songbirds the site of this coordination is suspected to be the nucleus retroambigualis (RAm), because it contains premotor neurons projecting upon both vocal motoneurons and spinal motoneurons innervating expiratory muscles, and because it receives descending inputs from the telencephalic vocal control nucleus robustus archopallialis (RA). Here we

“…The pathways by which lordosis is activated in mammals are thought to be mediated by VMH projections to the lateral periaqueductal gray (PAG; Canteras et al, ; Krieger et al, ), from PAG to nucleus retroambiguus (NRA) in the caudal medulla, and projections of NRA to motoneurons at several levels of the spinal cord that innervate the host of muscles involved in reproductive behavior (Daniels et al, ; Gerrits & Holstege, ; Gerrits, Vodde, & Holstege, ; VanderHorst & Holstege, ).…”

Section: Discussionmentioning

confidence: 99%

The ventromedial hypothalamic nucleus in the zebra finch (Taeniopygia guttata): Afferent and efferent projections in relation to the control of reproductive behavior

Wild

2017

Sex-specific mating behaviors occur in a variety of mammals, with the medial preoptic nucleus (POM) and the ventromedial hypothalamic nucleus (VMH) mediating control of male and female sexual behavior, respectively. In birds, likewise, POM is predominantly involved in the control of male reproductive behavior, but the degree to which VMH is involved in female reproductive behavior is unclear. Here, in male and female zebra finches, a combination of aromatase immunohistochemistry and conventional tract tracing facilitated the definition of two separate but adjacent nuclei in the basal hypothalamus: an oblique band of aromatase-positive (AR+) neurons, and ventromedial to this, an ovoid, aromatase-negative (AR-) nucleus. The AR- nucleus, but not the AR+ nucleus, was here shown to receive a projection from rostral parts of the thalamic auditory nucleus ovoidalis and from the nucleus of the tractus ovoidalis. The AR- nucleus also receives an overlapping, major projection from previously uncharted regions of the medial arcopallium and a minor projection from the caudomedial nidopallium. Both the AR- and the AR+ nuclei project to the intercollicular nucleus of the midbrain. No obvious sex differences in either the pattern of AR immunoreactivity or of the afferent projections to the AR- nucleus were observed. The significance of these results in terms of the acoustic control of avian reproductive behavior is discussed, and a comparison with the organization of VMH afferents in lizards suggests a homologous similarity of the caudal telencephalon in sauropsids.