Organization of afferent and efferent projections of the nucleus basalis prosencephali in a passerine,Taeniopygia guttata

Abstract

The connections of nucleus basalis (NB) of the rostral forebrain of the zebra finch were investigated electrophysiologically and with anterograde and retrograde tracing methods to determine their functional organization, the sources of their pontine afferents, and the targets of their telencephalic efferents. The nucleus was found to be partitioned into three major components, a rostral lingual part that received a hypoglossal projection via a lateral subnucleus of the principal sensory trigeminal nucleus (PrV), a middle beak part that received a trigeminal projection via a medial subnucleus of PrV, and a caudal auditory part that received a short latency auditory projection via the intermediate nucleus of the lateral lemniscus. Beak NB also received a projection from a paralateral lemniscal nucleus, and the dorsocaudal part of auditory NB and the medially adjacent neostriatum also received a projection from a lateral subnucleus of the superior vestibular nucleus (VS). The efferent projections of each of the three major parts of NB were mainly to the adjacent neostriatum frontale (NF), which then provided projections to the lobus parolfactorius (exclusive of area X), the lateral archistriatum intermedium (Ail), and the lateral neostriatum caudale (NCl). Ail received a projection from NCl and provided terminal fields to the contralateral NCl and the NF. The major projections of Ail, however, descended bilaterally through the brainstem via the occipitomesencephalic tracts, with dense terminations in the medial spiriform nucleus and with extensive bilateral terminations throughout the lateral reticular formation of the pons and medulla. For the most part, jaw, tongue, and tracheosyringeal motor nuclei did not receive terminations. The results suggest that NB in zebra finch, like NB in pigeon and duck, is likely to be a major component of trigeminal sensorimotor circuitry involved in feeding and in other oral-manipulative behaviors. Results also show that the auditory component of NB is not directly linked to the vocal control system at telencephalic levels, but the possibility remains that the lingual, beak, and auditory parts of NB play a role in vocalization by multisynaptic influences on cranial nerve motor nuclei innervating various parts of the vocal tract.

Magnetic field-driven induction of ZENK in the trigeminal system of pigeons ( Columba livia )

“…What would actually be the prediction if we imagine a scenario where the vestibular system, not the trigeminal system, would be the source of the magnetic activation we have observed in PrV and SpV? That would mean (i) that the activation of PrV and SpV observed in the CMF condition would represent a combination of vestibular magnetic input and non-magnetic trigeminal input (mechanical [41,42] or maybe even olfactory [43,44]); (ii) that the activation of PrV and SpV in the ZMF condition would represent only nonmagnetic trigeminal input and (iii) that the activation of PrV and SpV in the CMF-sect. group would represent only vestibular magnetic input ( figure 5).…”

Expression analysis of the speech-related genes FoxP1 and FoxP2 and their relation to singing behavior in two songbird species

“…The Bas is involved in feeding and oral-manipulative behaviors other than vocalization and does not anatomically connect to the vocal control system in songbirds (Wild and Farabaugh, 1996). Because both male and female finches engage in oral movements related to feeding behavior, it is not surprising that FoxP1 levels in the Bas are similar in both sexes.…”

Revised nomenclature for avian telencephalon and some related brainstem nuclei

“…Because the structure that has been known as the nucleus basalis also shows a core and shell organization, a similar problem exists for it ( Fig. 7D; Wild and Zeigler, 1980;Wild et al, 1985;Veenman and Gottschaldt, 1986;Dubbeldam and Visser, 1987;Wild and Farabaugh, 1996). The Forum concluded that it would be desirable to develop a uniform and consistent terminology for these three sensory areas in the nidopallium and will make recommendations in a separate publication specifically devoted to this issue, in the special nomenclature issue of Brain, Behavior and Evolution.…”

“…The structure that has been called nucleus basalis in birds is not located in the subpallium and is not a cholinergic cell group, but rather is a trigeminorecipient pallial sensory cell group (Witkovsky et al, 1973;Wild et al, 1985) and, in some species, also a general somatosensory recipient nucleus (Wild et al, , 2001. It also receives an auditory input from the nucleus of the lateral lemniscus, as well as an input from the vestibular system ( (Arends and Zeigler, 1986;Wild and Farabaugh, 1996;Wild et al, 2001). To prevent confusion with the cholinergic nucleus basalis of mammals, the Forum recommended that the old nucleus basalis of birds be renamed the nucleus basorostralis of the pallium, which describes its position in the telencephalon, with no abbreviation change (Table 4, Figs.…”

“…6C, 7E, 9A). As in the case of the fiber bundle previously called the tractus septo-mesencephalicus, the Forum noted that the "-mesencephalicus" part of the name might be construed to suggest that the OM projects only to the midbrain, which is not the case (Zeier and Karten, 1971;Wild and Farabaugh, 1996). Nonetheless, the value in retaining the abbreviation for OM was thought to outweigh any slightly misleading connotation in the term OM.…”