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Gómez-Martínez M, Rincón H, Gómez-Álvarez M, Gómez-Nieto R, Saldaña E. The nuclei of the lateral lemniscus: unexpected players in the descending auditory pathway. Front Neuroanat 2023; 17:1242245. [PMID: 37621862 PMCID: PMC10445163 DOI: 10.3389/fnana.2023.1242245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 07/10/2023] [Indexed: 08/26/2023] Open
Abstract
Introduction In the mammalian auditory pathway, the nuclei of the lateral lemniscus (NLL) are thought to be exclusively involved in the bottom-up transmission of auditory information. However, our repeated observation of numerous NLL neurons labeled after injection of retrograde tracers into the superior olivary complex (SOC) led us to systematically investigate with retrograde tracers the descending projections from the NLL to the SOC of the rat. Methods We performed large injections of FluoroGold into the SOC to determine NLL contributions to descending projections, and focal injections of biotinylated dextran amine (BDA) to pinpoint the specific nuclei of the SOC innervated by each NLL. Results The SOC is innervated by thousands of neurons distributed across four nuclei or regions associated with the lateral lemniscus: the ipsilateral ventral and intermediate nuclei of the lateral lemniscus (VNLL and INLL); the medial paralemniscal region (PL) of both sides; and the ipsilateral semilunar nucleus (SLN), a previously unrecognized nucleus that wraps around the INLL dorsally, medially, and caudally and consists of small, flat neurons. In some experiments, at least 30% of neurons in the VNLL and INLL were retrogradely labeled. All nuclei of the SOC, except the medial and lateral superior olives, are innervated by abundant lemniscal neurons, and each SOC nucleus receives a unique combination of lemniscal inputs. The primary target of the projections from the VNLL is the ventral nucleus of the trapezoid body (VNTB), followed by the superior paraolivary nucleus (SPON), and the medial nucleus of the trapezoid body (MNTB). The INLL selectively innervates the VNTB. The PL innervates dorsal periolivary regions bilaterally. The SLN preferentially innervates the MNTB and may provide the first identified non-calyceal excitatory input to MNTB neurons. Discussion Our novel findings have strong implications for understanding acoustic information processing in the initial stages of the auditory pathway. Based on the proportion of lemniscal neurons involved in all the projections described, the NLL should be considered major players in the descending auditory pathway.
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Affiliation(s)
- Mario Gómez-Martínez
- Neuroscience Institute of Castilla y León, University of Salamanca, Salamanca, Spain
- Department of Cell Biology and Pathology, Medical School, University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca, Salamanca, Spain
| | - Héctor Rincón
- Neuroscience Institute of Castilla y León, University of Salamanca, Salamanca, Spain
- Department of Cell Biology and Pathology, Medical School, University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca, Salamanca, Spain
| | - Marcelo Gómez-Álvarez
- Neuroscience Institute of Castilla y León, University of Salamanca, Salamanca, Spain
- Department of Cell Biology and Pathology, Medical School, University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca, Salamanca, Spain
| | - Ricardo Gómez-Nieto
- Neuroscience Institute of Castilla y León, University of Salamanca, Salamanca, Spain
- Department of Cell Biology and Pathology, Medical School, University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca, Salamanca, Spain
| | - Enrique Saldaña
- Neuroscience Institute of Castilla y León, University of Salamanca, Salamanca, Spain
- Department of Cell Biology and Pathology, Medical School, University of Salamanca, Salamanca, Spain
- Institute of Biomedical Research of Salamanca, Salamanca, Spain
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Liang H, Paxinos G. Afferents of the mouse linear nucleus. Mol Brain 2020; 13:67. [PMID: 32370769 PMCID: PMC7201812 DOI: 10.1186/s13041-020-00602-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/08/2020] [Indexed: 11/10/2022] Open
Abstract
The linear nucleus (Li) was identified in 1978 from its projections to the cerebellum. However, there is no systematic study of its connections with other areas of the central nervous system possibly due to the challenge of injecting retrograde tracers into this nucleus. The present study examines its afferents from some nuclei involved in motor and cardiovascular control with anterograde tracer injections. BDA injections into the central amygdaloid nucleus result in labeled fibers to the ipsilateral Li. Bilateral projections with an ipsilateral dominance were observed after injections in a) jointly the paralemniscal nucleus, the noradrenergic group 7/ Köllike -Fuse nucleus/subcoeruleus nucleus, b) the gigantocellular reticular nucleus, c) and the solitary nucleus/the parvicellular/intermediate reticular nucleus. Retrogradely labeled neurons were observed in Li after BDA injections into all these nuclei except the central amygdaloid and the paralemniscal nuclei. Our results suggest that Li is involved in a variety of physiological functions apart from motor and balance control it may exert via its cerebellar projections.
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Affiliation(s)
- Huazheng Liang
- Department of Neurology, Translational Research Institute of Brain and Brain-like Intelligence, Shanghai Fourth People's Hospital Affiliated to Tongji University School of Medicine, 1878 North Sichuan Road, Hongkou District, Shanghai, 200081, China. .,Neuroscience Research Australia, Sydney, NSW, 2031, Australia.
| | - George Paxinos
- Neuroscience Research Australia, Sydney, NSW, 2031, Australia
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Bilella A, Alvarez-Bolado G, Celio MR. TheFoxb1-expressing neurons of the ventrolateral hypothalamic parvafox nucleus project to defensive circuits. J Comp Neurol 2016; 524:2955-81. [DOI: 10.1002/cne.24057] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 03/03/2016] [Accepted: 06/09/2016] [Indexed: 02/04/2023]
Affiliation(s)
- Alessandro Bilella
- Anatomy Unit and Program in Neuroscience, Department of Medicine, Faculty of Sciences, University of Fribourg; CH-1700 Fribourg Switzerland
| | - Gonzalo Alvarez-Bolado
- Institute of Anatomy and Cell Biology, University of Heidelberg; 69120 Heidelberg Germany
| | - Marco R. Celio
- Anatomy Unit and Program in Neuroscience, Department of Medicine, Faculty of Sciences, University of Fribourg; CH-1700 Fribourg Switzerland
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Liang H, Watson C, Paxinos G. Terminations of reticulospinal fibers originating from the gigantocellular reticular formation in the mouse spinal cord. Brain Struct Funct 2015; 221:1623-33. [PMID: 25633472 DOI: 10.1007/s00429-015-0993-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 01/14/2015] [Indexed: 10/24/2022]
Abstract
The present study investigated the projections of the gigantocellular reticular nucleus (Gi) and its neighbors--the dorsal paragigantocellular reticular nucleus (DPGi), the alpha/ventral part of the gigantocellular reticular nucleus (GiA/V), and the lateral paragigantocellular reticular nucleus (LPGi)--to the mouse spinal cord by injecting the anterograde tracer biotinylated dextran amine (BDA) into the Gi, DPGi, GiA/GiV, and LPGi. The Gi projected to the entire spinal cord bilaterally with an ipsilateral predominance. Its fibers traveled in both the ventral and lateral funiculi with a greater presence in the ventral funiculus. As the fibers descended in the spinal cord, their density in the lateral funiculus increased. The terminals were present mainly in laminae 7-10 with a dorsolateral expansion caudally. In the lumbar and sacral cord, a considerable number of terminals were also present in laminae 5 and 6. Contralateral fibers shared a similar pattern to their ipsilateral counterparts and some fibers were seen to cross the midline. Fibers arising from the DPGi were similarly distributed in the spinal cord except that there was no dorsolateral expansion in the lumbar and sacral segments and there were fewer fiber terminals. Fibers arising from GiA/V predominantly traveled in the ventral and lateral funiculi ipsilaterally. Ipsilaterally, the density of fibers in the ventral funiculus decreased along the rostrocaudal axis, whereas the density of fibers in the lateral funiculus increased. They terminate mainly in the medial ventral horn and lamina 10 with a smaller number of fibers in the dorsal horn. Fibers arising from the LPGi traveled in both the ventral and lateral funiculi and the density of these fibers in the ventral and lateral funiculi decreased dramatically in the lumbar and sacral segments. Their terminals were present in the ventral horn with a large portion of them terminating in the motor neuron columns. The present study is the first demonstration of the termination pattern of fibers arising from the Gi, DPGi, GiA/GiV, and LPGi in the mouse spinal cord. It provides an anatomical foundation for those who are conducting spinal cord injury and locomotion related research.
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Affiliation(s)
- Huazheng Liang
- Neuroscience Research Australia, Barker Street, Randwick, NSW, 2031, Australia. .,School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Charles Watson
- Neuroscience Research Australia, Barker Street, Randwick, NSW, 2031, Australia
| | - George Paxinos
- Neuroscience Research Australia, Barker Street, Randwick, NSW, 2031, Australia.,School of Medical Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
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Liang H, Watson C, Paxinos G. Projections from the oral pontine reticular nucleus to the spinal cord of the mouse. Neurosci Lett 2014; 584:113-8. [PMID: 25459287 DOI: 10.1016/j.neulet.2014.10.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/07/2014] [Accepted: 10/11/2014] [Indexed: 11/19/2022]
Abstract
The present study investigated projections of the mouse oral pontine reticular nucleus (PnO) to the spinal cord by (a) injecting a retrograde tracer fluoro-gold (FG) to the lumbar cord and (b) an anterograde tracer biotinylated dextran amine (BDA) to PnO. We found that PnO projects to the entire spinal cord with an ipsilateral predominance. PnO fibers mainly travel in the ipsilateral ventral funiculus in the entire cord, terminating in laminae 7-10 with a lower density of fibers and boutons in lower segments. A small number of fibers travel in the contralateral ventral funiculus in the cervical cord with a similar terminating pattern to the ipsilateral counterpart. The present study is the first demonstration of PnO fiber terminals in the mouse spinal cord. This pathway might be responsible for muscle atonia during REM sleep, but needs physiological research to confirm this.
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Affiliation(s)
- Huazheng Liang
- Neuroscience Research Australia, Barker Street, Randwick 2031, NSW, Australia.
| | - Charles Watson
- Neuroscience Research Australia, Barker Street, Randwick 2031, NSW, Australia
| | - George Paxinos
- Neuroscience Research Australia, Barker Street, Randwick 2031, NSW, Australia; School of Medical Sciences, The University of New South Wales, Sydney 2052, NSW, Australia
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Zampieri N, Jessell TM, Murray AJ. Mapping sensory circuits by anterograde transsynaptic transfer of recombinant rabies virus. Neuron 2014; 81:766-78. [PMID: 24486087 DOI: 10.1016/j.neuron.2013.12.033] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2013] [Indexed: 01/14/2023]
Abstract
Primary sensory neurons convey information from the external world to relay circuits within the CNS, but the identity and organization of the neurons that process incoming sensory information remains sketchy. Within the CNS, viral tracing techniques that rely on retrograde transsynaptic transfer provide a powerful tool for delineating circuit organization. Viral tracing of the circuits engaged by primary sensory neurons has, however, been hampered by the absence of a genetically tractable anterograde transfer system. In this study, we demonstrate that rabies virus can infect sensory neurons in the somatosensory system, is subject to anterograde transsynaptic transfer from primary sensory to spinal target neurons, and can delineate output connectivity with third-order neurons. Anterograde transsynaptic transfer is a feature shared by other classes of primary sensory neurons, permitting the identification and potentially the manipulation of neural circuits processing sensory feedback within the mammalian CNS.
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Affiliation(s)
- Niccolò Zampieri
- Departments of Neuroscience and Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Kavli Institute for Brain Science, Columbia University, New York, NY 10032 USA
| | - Thomas M Jessell
- Departments of Neuroscience and Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Kavli Institute for Brain Science, Columbia University, New York, NY 10032 USA.
| | - Andrew J Murray
- Departments of Neuroscience and Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Kavli Institute for Brain Science, Columbia University, New York, NY 10032 USA
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