Review: Cytological characteristics of commissural and tuberculo-ventral neurons in the rat dorsal cochlear nucleus

Alibardi, Lorenzo

doi:10.1016/j.heares.2006.01.005

Cited by 13 publications

(8 citation statements)

References 46 publications

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“…In addition, a portion of β-gal-positive DCN cells were found to be immunopositive to glycine (Fig. 2D, arrowheads), suggesting that they are tuberculo-ventral cells (Willott et al, 1997;Alibardi, 2006). In the FCL of the DCN, many round β-gal-positive cells express CaMKIIα (Fig.…”

Section: Cn Neurons Derived From Ptf1a Neuroepithelial Domainmentioning

confidence: 95%

Inhibitory and excitatory subtypes of cochlear nucleus neurons are defined by distinct bHLH transcription factors, Ptf1a and Atoh1

et al. 2009

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The cochlear nucleus (CN), which consists of dorsal and ventral cochlear nuclei (DCN and VCN), plays pivotal roles in processing and relaying auditory information to the brain. Although it contains various types of neurons, the origins of the distinct subtypes and their developmental molecular machinery are still elusive. Here we reveal that two basic helix-loop-helix transcription factors play crucial roles in specifying neuron subtypes in the CN. Pancreatic transcription factor 1a (Ptf1a) and atonal homolog 1 (Atoh1) were found to be expressed in discrete dorsolateral regions of the embryonic neuroepithelia of the middle hindbrain (rhombomeres 2-5). Genetic lineage tracing using mice that express Cre recombinase from the Ptf1a locus or under the control of the Atoh1 promoter revealed that inhibitory (GABAergic and glycinergic) or excitatory (glutamatergic) neurons of both DCN and VCN are derived from the Ptf1a-and Atoh1-expressing neuroepithelial regions, respectively. In the Ptf1a or Atoh1 null embryos, production of inhibitory or excitatory neurons, respectively, was severely inhibited in the CN. These findings suggest that inhibitory and excitatory subtypes of CN neurons are defined by Ptf1a and Atoh1, respectively and, furthermore, provide important insights into understanding the machinery of neuron subtype specification in the dorsal hindbrain.

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Section: Cn Neurons Derived From Ptf1a Neuroepithelial Domainmentioning

confidence: 95%

Inhibitory and excitatory subtypes of cochlear nucleus neurons are defined by distinct bHLH transcription factors, Ptf1a and Atoh1

et al. 2009

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“…The density of UBCs was highest in the dorsal cochlear nucleus compared to other regions of the granule cell system and the ventral nucleus (Diño and Mugnaini, 2008). Detailed UBC maps in the cochlear nuclear complex of other species are lacking, although UBCs or forms of the UBC named shrub cells, mitt cells and chestnut cells, have been described by electron microscopy and/or immunocytochemistry in the cochlear nuclei of mouse, chinchilla, guinea pig and cat (Brawer et al, 1974; Hutson and Morest, 1996; Weedman et al, 1996; Morest, 1997; Hurd et al, 1999; Josephson and Morest, 2003; Alibardi, 2004, 2006; Meltzer and Ryugo, 2006). UBCs have also been identified in the cochlear nuclei of non-human primates and human, although in these species the granule cell system has become rudimentary (Spatz, 1999, 2000, 2001; Rubio et al, 2008).…”

Section: Comparative Studies On Ubcs In Mammalian Cochlear Nuclear Comentioning

confidence: 99%

The unipolar brush cell: A remarkable neuron finally receiving deserved attention

Mugnaini

Sekerková

Martina

2011

Brain Research Reviews

167

152

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Unipolar brush cells (UBC) are small, glutamatergic neurons residing in the granular layer of the cerebellar cortex and the granule cell domain of the cochlear nuclear complex. Recent studies indicate that this neuronal class consists of three or more subsets characterized by distinct chemical phenotypes, as well as by intrinsic properties that may shape their synaptic responses and firing patterns. Yet, all UBCs have a unique morphology, as both the dendritic brush and the large endings of the axonal branches participate in the formation of glomeruli. Although UBCs and granule cells may share the same excitatory and inhibitory inputs, the two cell types are distinctively differentiated. Typically, whereas the granule cell has 4-5 dendrites that are innervated by different mossy fibers, and an axon that divides only once to form parallel fibers after ascending to the molecular layer, the UBC has but one short dendrite whose brush engages in synaptic contact with a single mossy fiber terminal, and an axon that branches locally in the granular layer; branches of UBC axons form a non-canonical, cortex-intrinsic category of mossy fibers synapsing with granule cells and other UBCs. This is thought to generate a feed-forward amplification of single mossy fiber afferent signals that would reach the overlying Purkinje cells via ascending granule cell axons and their parallel fibers.In sharp contrast to other classes of cerebellar neurons, UBCs are not distributed homogeneously across cerebellar lobules, and subsets of UBCs also show different, albeit overlapping, distributions. UBCs are conspicuously rare in the expansive lateral cerebellar areas targeted by the cortico-ponto-cerebellar pathway, while they are a constant component of the vermis and the flocculonodular lobe. The presence of UBCs in cerebellar regions involved in the sensorimotor processes that regulate body, head and eye position, as well as in regions of the cochlear nucleus that process sensorimotor information suggests a key role in these critical functions; it also invites further efforts to clarify the cellular biology of the UBCs and their specific functions in the neuronal microcircuits in which they are embedded. High density of UBCs in specific regions of the cerebellar cortex is a feature largely conserved across mammals and suggests an involvement of these neurons in fundamental aspects of the input/output organization as well as in clinical manifestation of focal cerebellar disease.

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“…Cumulative evidence suggests that some CN-commissural neurons are excitatory (Alibardi 1998;Babalian et al 2002;Shore et al 1992). Alibardi (1998Alibardi ( , 2000Alibardi ( , 2006 reported that about 60% of CN-commissural neurons are immunonegative to glycine or GABA. Furthermore, electron microscopic examination revealed that most large CN-commissural terminals in the GCD contained round vesicles and formed asymmetric synapses, suggestive of excitatory synapses (Alibardi 2000(Alibardi , 2006.…”

Section: Introductionmentioning

confidence: 99%

“…Alibardi (1998Alibardi ( , 2000Alibardi ( , 2006 reported that about 60% of CN-commissural neurons are immunonegative to glycine or GABA. Furthermore, electron microscopic examination revealed that most large CN-commissural terminals in the GCD contained round vesicles and formed asymmetric synapses, suggestive of excitatory synapses (Alibardi 2000(Alibardi , 2006. In contrast, the majority of CN-commissural terminal boutons in the central regions of VCN contained pleomorphic vesicles and formed symmetric synaptic thickenings.…”

Section: Introductionmentioning

confidence: 99%

Vesicular Glutamate Transporter 2 Is Associated with the Cochlear Nucleus Commissural Pathway

Zhou

Zeng

Cui

et al. 2010

JARO

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The cochlear nucleus (CN) is the first auditory structure to receive binaural information via CN-commissural connections. In spite of an abundance of evidence that CN-commissural neurons are glycinergic and thus inhibitory, physiological, and anatomical evidence suggests that a small group of CN-commissural neurons are excitatory. In this study, we examined the excitatory portion of the CN-commissural pathway by combining anterograde tract tracing with immunohistochemistry of vesicular glutamate transporters (VGLUTs) and retrograde tract tracing with immunohistochemistry of glycine and GABA. VGLUTs accumulate glutamate in synaptic vesicles and are prime markers for glutamatergic neurons. The terminal endings of CN-commissural projections were typically en passant or small terminal boutons, but large, irregular swellings were also observed, confined to the granule cell domain (GCD). Both small and large terminal endings in the GCD colabeled with VGLUT2, but not VGLUT1. In addition, some CN-commissural cells themselves received VGLUT2-positive puncta on their somata. After large injections into the CN, 37% of the total number of retrogradely labeled commissural neurons was immunonegative to glycine or GABA. Retrograde labeling after a restricted GCD injection revealed a majority of putative excitatory CN-commissural neurons as multipolar, in the marginal regions of the ventral CN, medially as well as in the small cell cap region and deep dorsal CN. These results provide direct anatomical evidence that an excitatory commissural projection is present, and VGLUT2 is associated with this pathway both as its source and as a recipient.

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Review: Cytological characteristics of commissural and tuberculo-ventral neurons in the rat dorsal cochlear nucleus

Cited by 13 publications

References 46 publications

Inhibitory and excitatory subtypes of cochlear nucleus neurons are defined by distinct bHLH transcription factors, Ptf1a and Atoh1

Inhibitory and excitatory subtypes of cochlear nucleus neurons are defined by distinct bHLH transcription factors, Ptf1a and Atoh1

The unipolar brush cell: A remarkable neuron finally receiving deserved attention

Vesicular Glutamate Transporter 2 Is Associated with the Cochlear Nucleus Commissural Pathway

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