1
|
Silva-Hucha S, Fernández de Sevilla ME, Humphreys KM, Benson FE, Franco JM, Pozo D, Pastor AM, Morcuende S. VEGF expression disparities in brainstem motor neurons of the SOD1 G93A ALS model: Correlations with neuronal vulnerability. Neurotherapeutics 2024; 21:e00340. [PMID: 38472048 DOI: 10.1016/j.neurot.2024.e00340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 02/08/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rare neuromuscular disease characterized by severe muscle weakness mainly due to degeneration and death of motor neurons. A peculiarity of the neurodegenerative processes is the variable susceptibility among distinct neuronal populations, exemplified by the contrasting resilience of motor neurons innervating the ocular motor system and the more vulnerable facial and hypoglossal motor neurons. The crucial role of vascular endothelial growth factor (VEGF) as a neuroprotective factor in the nervous system is well-established since a deficit of VEGF has been related to motoneuronal degeneration. In this study, we investigated the survival of ocular, facial, and hypoglossal motor neurons utilizing the murine SOD1G93A ALS model at various stages of the disease. Our primary objective was to determine whether the survival of the different brainstem motor neurons was linked to disparate VEGF expression levels in resilient and susceptible motor neurons throughout neurodegeneration. Our findings revealed a selective loss of motor neurons exclusively within the vulnerable nuclei. Furthermore, a significantly higher level of VEGF was detected in the more resistant motor neurons, the extraocular ones. We also examined whether TDP-43 dynamics in the brainstem motor neuron of SOD mice was altered. Our data suggests that the increased VEGF levels observed in extraocular motor neurons may potentially underlie their resistance during the neurodegenerative processes in ALS in a TDP-43-independent manner. Our work might help to better understand the underlying mechanisms of selective vulnerability of motor neurons in ALS.
Collapse
Affiliation(s)
- Silvia Silva-Hucha
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain; Cell and Developmental Biology, University College London, Medawar Building, Gower Street, London WC1E 6BT, UK
| | | | - Kirsty M Humphreys
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Fiona E Benson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster LA1 4YQ, UK
| | - Jaime M Franco
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucía-Universidad Pablo de Olavide-Universidad de Sevilla-CSIC, 41092, Seville, Spain
| | - David Pozo
- Andalusian Center of Molecular Biology and Regenerative Medicine-CABIMER, Junta de Andalucía-Universidad Pablo de Olavide-Universidad de Sevilla-CSIC, 41092, Seville, Spain; Department of Medical Biochemistry, Molecular Biology and Immunology, Universidad de Sevilla Medical School, 41009 Seville, Spain
| | - Angel M Pastor
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain.
| | - Sara Morcuende
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Seville, Spain.
| |
Collapse
|
2
|
Fontán-Lozano Á, Morcuende S, Davis-López de Carrizosa MA, Benítez-Temiño B, Mejías R, Matarredona ER. To Become or Not to Become Tumorigenic: Subventricular Zone Versus Hippocampal Neural Stem Cells. Front Oncol 2020; 10:602217. [PMID: 33330101 PMCID: PMC7729188 DOI: 10.3389/fonc.2020.602217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 10/29/2020] [Indexed: 12/12/2022] Open
Abstract
Neural stem cells (NSCs) persist in the adult mammalian brain in two neurogenic regions: the subventricular zone lining the lateral ventricles and the dentate gyrus of the hippocampus. Compelling evidence suggests that NSCs of the subventricular zone could be the cell type of origin of glioblastoma, the most devastating brain tumor. Studies in glioblastoma patients revealed that NSCs of the tumor-free subventricular zone, harbor cancer-driver mutations that were found in the tumor cells but were not present in normal cortical tissue. Endogenous mutagenesis can also take place in hippocampal NSCs. However, to date, no conclusive studies have linked hippocampal mutations with glioblastoma development. In addition, glioblastoma cells often invade or are closely located to the subventricular zone, whereas they do not tend to infiltrate into the hippocampus. In this review we will analyze possible causes by which subventricular zone NSCs might be more susceptible to malignant transformation than their hippocampal counterparts. Cellular and molecular differences between the two neurogenic niches, as well as genotypic and phenotypic characteristics of their respective NSCs will be discussed regarding why the cell type originating glioblastoma brain tumors has been linked mainly to subventricular zone, but not to hippocampal NSCs.
Collapse
|
3
|
Silva-Hucha S, Carrero-Rojas G, Fernández de Sevilla ME, Benítez-Temiño B, Davis-López de Carrizosa MA, Pastor AM, Morcuende S. Sources and lesion-induced changes of VEGF expression in brainstem motoneurons. Brain Struct Funct 2020; 225:1033-1053. [PMID: 32189115 DOI: 10.1007/s00429-020-02057-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 03/06/2020] [Indexed: 12/31/2022]
Abstract
Motoneurons of the oculomotor system show lesser vulnerability to neurodegeneration compared to other cranial motoneurons, as seen in amyotrophic lateral sclerosis (ALS). The overexpression of vascular endothelial growth factor (VEGF) is involved in motoneuronal protection. As previously shown, motoneurons innervating extraocular muscles present a higher amount of VEGF and its receptor Flk-1 compared to facial or hypoglossal motoneurons. Therefore, we aimed to study the possible sources of VEGF to brainstem motoneurons, such as glial cells and target muscles. We also studied the regulation of VEGF in response to axotomy in ocular, facial, and hypoglossal motor nuclei. Basal VEGF expression in astrocytes and microglial cells of the cranial motor nuclei was low. Although the presence of VEGF in the different target muscles for brainstem motoneurons was similar, the presynaptic element of the ocular neuromuscular junction showed higher amounts of Flk-1, which could result in greater efficiency in the capture of the factor by oculomotor neurons. Seven days after axotomy, a clear glial reaction was observed in all the brainstem nuclei, but the levels of the neurotrophic factor remained low in glial cells. Only the injured motoneurons of the oculomotor system showed an increase in VEGF and Flk-1, but such an increase was not detected in axotomized facial or hypoglossal motoneurons. Taken together, our findings suggest that the ocular motoneurons themselves upregulate VEGF expression in response to lesion. In conclusion, the low VEGF expression observed in glial cells suggests that these cells are not the main source of VEGF for brainstem motoneurons. Therefore, the higher VEGF expression observed in motoneurons innervating extraocular muscles is likely due either to the fact that this factor is more avidly taken up from the target muscles, in basal conditions, or is produced by these motoneurons themselves, and acts in an autocrine manner after axotomy.
Collapse
Affiliation(s)
- Silvia Silva-Hucha
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Génova Carrero-Rojas
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | | | - Beatriz Benítez-Temiño
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | | | - Angel M Pastor
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Sara Morcuende
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain.
| |
Collapse
|
4
|
Acosta L, Morcuende S, Silva-Hucha S, Pastor AM, de la Cruz RR. Vascular Endothelial Growth Factor (VEGF) Prevents the Downregulation of the Cholinergic Phenotype in Axotomized Motoneurons of the Adult Rat. Front Mol Neurosci 2018; 11:241. [PMID: 30050409 PMCID: PMC6052088 DOI: 10.3389/fnmol.2018.00241] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/22/2018] [Indexed: 12/11/2022] Open
Abstract
Vascular endothelial growth factor (VEGF) was initially characterized by its activity on the vascular system. However, there is growing evidence indicating that VEGF also acts as a neuroprotective factor, and that its administration to neurons suffering from trauma or disease is able to rescue them from cell death. We questioned whether VEGF could also maintain damaged neurons in a neurotransmissive mode by evaluating the synthesis of their neurotransmitter, and whether its action would be direct or through its well-known angiogenic activity. Adult rat extraocular motoneurons were chosen as the experimental model. Lesion was performed by monocular enucleation and immediately a gelatine sponge soaked in VEGF was implanted intraorbitally. After 7 days, abducens, trochlear, and oculomotor nuclei were examined by immunohistochemistry against choline acetyltransferase (ChAT), the biosynthetic enzyme of the motoneuronal neurotransmitter acetylcholine. Lesioned motoneurons exhibited a noticeable ChAT downregulation which was prevented by VEGF administration. To explore whether this action was mediated via an increase in blood vessels or in their permeability, we performed immunohistochemistry against laminin, glucose transporter-1 and the plasmatic protein albumin. The quantification of the immunolabeling intensity against these three proteins showed no significant differences between VEGF-treated, axotomized and control animals. Therefore, the present data indicate that VEGF is able to sustain the cholinergic phenotype in damaged motoneurons, which is a first step for adequate neuromuscular neurotransmission, and that this action seems to be mediated directly on neurons since no sign of angiogenic activity was evident. These data reinforces the therapeutical potential of VEGF in motoneuronal diseases.
Collapse
Affiliation(s)
- Lourdes Acosta
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Sara Morcuende
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Silvia Silva-Hucha
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Angel M Pastor
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Rosa R de la Cruz
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| |
Collapse
|
5
|
Hernández RG, Silva-Hucha S, Morcuende S, de la Cruz RR, Pastor AM, Benítez-Temiño B. Extraocular Motor System Exhibits a Higher Expression of Neurotrophins When Compared with Other Brainstem Motor Systems. Front Neurosci 2017; 11:399. [PMID: 28744196 PMCID: PMC5504184 DOI: 10.3389/fnins.2017.00399] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 06/26/2017] [Indexed: 01/01/2023] Open
Abstract
Extraocular motoneurons resist degeneration in diseases such as amyotrophic lateral sclerosis. The main objective of the present work was to characterize the presence of neurotrophins in extraocular motoneurons and muscles of the adult rat. We also compared these results with those obtained from other cranial motor systems, such as facial and hypoglossal, which indeed suffer neurodegeneration. Immunocytochemical analysis was used to describe the expression of nerve growth factor, brain-derived neurotrophic factor and neurotrophin-3 in oculomotor, trochlear, abducens, facial, and hypoglossal nuclei of adult rats, and Western blots were used to describe the presence of neurotrophins in extraocular, facial (buccinator), and tongue muscles, which are innervated by the above-mentioned motoneurons. In brainstem samples, brain-derived neurotrophic factor was present both in extraocular and facial motoneuron somata, and to a lesser degree, in hypoglossal motoneurons. Neurotrophin-3 was present in extraocular motor nuclei, while facial and hypoglossal motoneurons were almost devoid of this protein. Finally, nerve growth factor was not present in the soma of any group of motoneurons, although it was present in dendrites of motoneurons located in the neuropil. Neuropil optical density levels were higher in extraocular motoneuron nuclei when compared with facial and hypoglossal nuclei. Neurotrophins could be originated in target muscles, since Western blot analyses revealed the presence of the three molecules in all sampled muscles, to a larger extent in extraocular muscles when compared with facial and tongue muscles. We suggest that the different neurotrophin availability could be related to the particular resistance of extraocular motoneurons to neurodegeneration.
Collapse
|
6
|
Silva-Hucha S, Hernández RG, Benítez-Temiño B, Pastor ÁM, de la Cruz RR, Morcuende S. Extraocular motoneurons of the adult rat show higher levels of vascular endothelial growth factor and its receptor Flk-1 than other cranial motoneurons. PLoS One 2017; 12:e0178616. [PMID: 28570669 PMCID: PMC5453543 DOI: 10.1371/journal.pone.0178616] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 05/16/2017] [Indexed: 12/23/2022] Open
Abstract
Recent studies show a relationship between the deficit of vascular endothelial growth factor (VEGF) and motoneuronal degeneration, such as that occurring in amyotrophic lateral sclerosis (ALS). VEGF delivery protects motoneurons from cell death and delayed neurodegeneration in animal models of ALS. Strikingly, extraocular motoneurons show lesser vulnerability to neurodegeneration in ALS compared to other cranial or spinal motoneurons. Therefore, the present study investigates possible differences in VEGF and its main receptor VEGFR-2 or Flk-1 between extraocular and non-extraocular brainstem motoneurons. We performed immunohistochemistry and Western blot to determine the presence of VEGF and Flk-1 in rat motoneurons located in the three extraocular motor nuclei (abducens, trochlear and oculomotor) and to compare it to that observed in two other brainstem nuclei (hypoglossal and facial) that are vulnerable to degeneration. Extraocular motoneurons presented higher amounts of VEGF and its receptor Flk-1 than other brainstem motoneurons, and thus these molecules could be participating in their higher resistance to neurodegeneration. In conclusion, we hypothesize that differences in VEGF availability and signaling could be a contributing factor to the different susceptibility of extraocular motoneurons, when compared with other motoneurons, in neurodegenerative diseases.
Collapse
Affiliation(s)
- Silvia Silva-Hucha
- Laboratorio de Fisiología y Plasticidad Neuronal, Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Rosendo G. Hernández
- Laboratorio de Fisiología y Plasticidad Neuronal, Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Beatriz Benítez-Temiño
- Laboratorio de Fisiología y Plasticidad Neuronal, Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Ángel M. Pastor
- Laboratorio de Fisiología y Plasticidad Neuronal, Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Rosa R. de la Cruz
- Laboratorio de Fisiología y Plasticidad Neuronal, Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
| | - Sara Morcuende
- Laboratorio de Fisiología y Plasticidad Neuronal, Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, Sevilla, Spain
- * E-mail:
| |
Collapse
|
7
|
Benítez-Temiño B, Davis-López de Carrizosa MA, Morcuende S, Matarredona ER, de la Cruz RR, Pastor AM. Functional Diversity of Neurotrophin Actions on the Oculomotor System. Int J Mol Sci 2016; 17:E2016. [PMID: 27916956 PMCID: PMC5187816 DOI: 10.3390/ijms17122016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 11/24/2016] [Accepted: 11/25/2016] [Indexed: 11/16/2022] Open
Abstract
Neurotrophins play a principal role in neuronal survival and differentiation during development, but also in the maintenance of appropriate adult neuronal circuits and phenotypes. In the oculomotor system, we have demonstrated that neurotrophins are key regulators of developing and adult neuronal properties, but with peculiarities depending on each neurotrophin. For instance, the administration of NGF (nerve growth factor), BDNF (brain-derived neurotrophic factor) or NT-3 (neurotrophin-3) protects neonatal extraocular motoneurons from cell death after axotomy, but only NGF and BDNF prevent the downregulation in ChAT (choline acetyltransferase). In the adult, in vivo recordings of axotomized extraocular motoneurons have demonstrated that the delivery of NGF, BDNF or NT-3 recovers different components of the firing discharge activity of these cells, with some particularities in the case of NGF. All neurotrophins have also synaptotrophic activity, although to different degrees. Accordingly, neurotrophins can restore the axotomy-induced alterations acting selectively on different properties of the motoneuron. In this review, we summarize these evidences and discuss them in the context of other motor systems.
Collapse
Affiliation(s)
- Beatriz Benítez-Temiño
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain.
| | | | - Sara Morcuende
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain.
| | - Esperanza R Matarredona
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain.
| | - Rosa R de la Cruz
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain.
| | - Angel M Pastor
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain.
| |
Collapse
|
8
|
Morcuende S, Muñoz-Hernández R, Benítez-Temiño B, Pastor AM, de la Cruz RR. Neuroprotective effects of NGF, BDNF, NT-3 and GDNF on axotomized extraocular motoneurons in neonatal rats. Neuroscience 2013; 250:31-48. [PMID: 23827308 DOI: 10.1016/j.neuroscience.2013.06.050] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 06/06/2013] [Accepted: 06/21/2013] [Indexed: 11/17/2022]
Abstract
Neurotrophic factors delivered from target muscles are essential for motoneuronal survival, mainly during development and early postnatal maturation. It has been shown that the disconnection between motoneurons and their innervated muscle by means of axotomy produces a vast neuronal death in neonatal animals. In the present work, we have evaluated the effects of different neurotrophic factors on motoneuronal survival after neonatal axotomy, using as a model the motoneurons innervating the extraocular eye muscles. With this purpose, neonatal rats were monocularly enucleated at the day of birth (postnatal day 0) and different neurotrophic treatments (NGF, BDNF, NT-3, GDNF and the mixture of BDNF+GDNF) were applied intraorbitally by means of a Gelfoam implant (a single dose of 5 μg of each factor). We first demonstrated that extraocular eye muscles of neonatal rats expressed these neurotrophic factors and therefore constituted a natural source of retrograde delivery for their innervating motoneurons. By histological and immunocytochemical methods we determined that all treatments significantly rescued extraocular motoneurons from axotomy-induced cell death. For the dose used, NGF and GDNF were the most potent survival factors for these motoneurons, followed by BDNF and lastly by NT-3. The simultaneous administration of BDNF and GDNF did not increase the survival-promoting effects above those obtained by GDNF alone. Interestingly, the rescue effects of all neurotrophic treatments persisted even 30 days after lesion. The administration of these neurotrophic factors, with the exception of NT-3, also prevented the loss of the cholinergic phenotype observed by 10 days after axotomy. At the dosage applied, NGF and GDNF were revealed again as the most effective neuroprotective agents against the axotomy-induced decrease in ChAT. Two remarkable findings highlighted in the present work that contrasted with other motoneuronal types after neonatal axotomy: first, the extremely high efficacy of NGF as a neuroprotective agent and, second, the long-lasting effects of neurotrophic administration on cell survival and ChAT expression in extraocular motoneurons.
Collapse
Affiliation(s)
- S Morcuende
- Departamento de Fisiología, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain
| | | | | | | | | |
Collapse
|
9
|
Morcuende S, Matarredona ER, Benítez-Temiño B, Muñoz-Hernández R, Pastor AM, de la Cruz RR. Differential regulation of the expression of neurotrophin receptors in rat extraocular motoneurons after lesion. J Comp Neurol 2011; 519:2335-52. [PMID: 21456016 DOI: 10.1002/cne.22630] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Neurotrophins acting through high-affinity tyrosine kinase receptors (trkA, trkB, and trkC) play a crucial role in regulating survival and maintenance of specific neuronal functions after injury. Adult motoneurons supplying extraocular muscles survive after disconnection from the target, but suffer dramatic changes in morphological and physiological properties, due in part to the loss of their trophic support from the muscle. To investigate the dependence of the adult rat extraocular motoneurons on neurotrophins, we examined trkA, trkB, and trkC mRNA expression after axotomy by in situ hybridization. trkA mRNA expression was detectable at low levels in unlesioned motoneurons, and its expression was downregulated 1 and 3 days after injury. Expression of trkB and trkC mRNAs was stronger, and after axotomy a simultaneous, but inverse regulation of both receptors was observed. Thus, whereas a considerable increase in trkB expression was seen about 2 weeks after axotomy, the expression of trkC mRNA had decreased at the same post-lesion period. Injured extraocular motoneurons also experienced an initial induction in expression of calcitonin gene-related peptide and a transient downregulation of cholinergic characteristics, indicating a switch in the phenotype from a transmitter-specific to a regenerative state. These results suggest that specific neurotrophins may contribute differentially to the survival and regenerative responses of extraocular motoneurons after lesion.
Collapse
Affiliation(s)
- Sara Morcuende
- Departamento de Fisiología y Zoología, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain
| | | | | | | | | | | |
Collapse
|
10
|
Márquez-Ruiz J, Morcuende S, Navarro-López JDD, Escudero M. Anatomical and pharmacological relationship between acetylcholine and nitric oxide in the prepositus hypoglossi nucleus of the cat: Functional implications for eye-movement control. J Comp Neurol 2007; 503:407-20. [PMID: 17503470 DOI: 10.1002/cne.21397] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The prepositus hypoglossi (PH) nucleus has been proposed as a pivotal structure for horizontal eye-position generation in the oculomotor system. Recent studies have revealed that acetylcholine (ACh) in the PH nucleus could mediate the persistent activity necessary for this process, although the origin of this ACh remains unknown. It is also known that nitric oxide (NO) in the PH nucleus plays an important role in the control of velocity balance, being involved in a negative feedback control of tonic signals arriving at the PH nucleus. As it could be expected that neurons taking part in eye-position generation must control their tonic background inputs, the existence of a relationship between nitrergic and cholinergic neurons is hypothesized. In the present study we analyzed the distribution, size, and morphology of choline acetyltransferase-positive neurons, and their relationship with neuronal nitric oxide synthase in the PH nucleus of the cat. As presumed, some 96% of cholinergic neurons were also nitrergic in the PH nucleus, suggesting that NO is regulating the level of ACh released by cholinergic PH neurons. Furthermore, we studied the alterations induced by muscarinic-receptor agonists and antagonists on spontaneous and vestibularly induced eye movements in the alert cat and compared them with those induced in previous studies by modification of NO levels in the same animal preparation. The results suggest that ACh is necessary for the generation of saccadic and vestibular eye-position signals, whereas the NO is stabilizing the eye-position generator by controlling background activity reaching cholinergic neurons in the PH nucleus.
Collapse
Affiliation(s)
- Javier Márquez-Ruiz
- Neurociencia y Comportamiento. Fac. de Biología, Universidad de Sevilla, 41012-Sevilla, Spain
| | | | | | | |
Collapse
|
11
|
Morcuende S, Benítez-Temiño B, Pecero ML, Pastor AM, de la Cruz RR. Abducens internuclear neurons depend on their target motoneurons for survival during early postnatal development. Exp Neurol 2005; 195:244-56. [PMID: 15935346 DOI: 10.1016/j.expneurol.2005.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Revised: 04/07/2005] [Accepted: 05/04/2005] [Indexed: 10/25/2022]
Abstract
The highly specific projection of abducens internuclear neurons onto medial rectus motoneurons in the oculomotor nucleus is a good model to evaluate the dependence on target cells for survival during development and in the adult. Thus, the procedure we chose to selectively deprive abducens internuclear neurons of their natural target was the enucleation of postnatal day 1 rats to induce the death of medial rectus motoneurons. Two months later, we evaluated both the extent of reduction in target size, by immunocytochemistry against choline acetyltransferase (ChAT) and Nissl counting, and the percentage of abducens internuclear neurons surviving target loss, by calretinin immunostaining and horseradish peroxidase (HRP) retrograde tracing. Firstly, axotomized oculomotor motoneurons died in a high percentage ( approximately 80%) as visualized 2 months after lesion. In addition, we showed a transient (1 month) and reversible down-regulation of ChAT expression in extraocular motoneurons induced by injury. Secondly, 2 months after enucleation, 61.6% and 60.5% of the population of abducens internuclear neurons appeared stained by retrograde tracing and calretinin immunoreaction, respectively, indicating a significant extent of cell death after target loss (38.4% or 39.5%). By contrast, in the adult rat, neither extraocular motoneurons died in response to axotomy nor abducens internuclear neurons died due to the loss of their target motoneurons induced by the retrograde transport of toxic ricin injected in the medial rectus muscle. These results indicate that, during development, abducens internuclear neurons depend on their target motoneurons for survival, and that they lose this dependence with maturation.
Collapse
Affiliation(s)
- Sara Morcuende
- Departamento de Fisiología y Zoología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012-Sevilla, Spain
| | | | | | | | | |
Collapse
|
12
|
González-Forero D, Morcuende S, Alvarez FJ, de la Cruz RR, Pastor AM. Transynaptic effects of tetanus neurotoxin in the oculomotor system. ACTA ACUST UNITED AC 2005; 128:2175-88. [PMID: 15987757 DOI: 10.1093/brain/awh580] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The question whether general tetanus arises from the independent sum of multiple local tetani or results from the actions of the transynaptic tetanus neurotoxin (TeNT) in higher brain centres remains unresolved. Despite the blood-borne dissemination of TeNT from an infected wound, the access to the central nervous system is probably prevented by the blood-brain barrier. However, several long-term sequelae (e.g. autonomic dysfunction, seizures, myoclonus, and sleep disturbances) present after the subsidence of muscle spasms might be indicative of central actions that occur farther away from lower motoneurons. Subsequently, the obvious entry route is the peripheral neurons followed by the transynaptic passage to the brain. We aimed at describing the pathophysiological correlates of TeNT translocation using the oculomotor system as a comprehensive model of cell connectivity and neuronal firing properties. In this study, we report that injection of TeNT into the medial rectus muscle of one eye resulted in bilateral gaze palsy attributed to firing alterations found in the contralaterally projecting abducens internuclear neurons. Functional alterations in the abducens-to-oculomotor internuclear pathway resembled in part the classically described TeNT disinhibition. We confirmed the transynaptic targeted action of TeNT by analysing vesicle-associated membrane protein2 (VAMP2) immunoreactivity (the SNARE protein cleaved by TeNT). VAMP2 immunoreactivity decreased by 94.4% in the oculomotor nucleus (the first synaptic relay) and by 62.1% presynaptic to abducens neurons (the second synaptic relay). These results are the first demonstration of physiological changes in chains of connected neurons that are best explained by the transynaptic action of TeNT on premotor neurons as shown with VAMP2 immunoreactivity which serves as an indicator of TeNT activity.
Collapse
|
13
|
Abstract
We examined the expression of the three Trk receptors for neurotrophins (TrkA, TrkB, and TrkC) in the extraocular motor nuclei of the adult cat by using antibodies directed against the full-Trk proteins in combination with horseradish peroxidase retrograde tracing. The three receptors were present in all neuronal populations investigated, including abducens motoneurons and internuclear neurons, medial rectus motoneurons of the oculomotor nucleus, and trochlear motoneurons. They were also present in the vestibular and prepositus hypoglossi nuclei. TrkA, TrkB, and TrkC immunopositive cells were found in similar percentages in the oculomotor and in the trochlear nuclei. In the abducens nucleus, however, a significantly higher percentage of cells expressed TrkB than the other two receptors, among both motoneurons (81.8%) and internuclear neurons (88.4%). The percentages obtained for the three Trk receptors in identified neuronal populations pointed to the colocalization of two or three receptors in a large number of cells. We used confocal microscopy to elucidate the subcellular location of Trk receptors. In this case, abducens motoneurons and internuclear neurons were identified with antibodies against choline acetyltransferase and calretinin, respectively. We found a different pattern of staining for each neurotrophin receptor, suggesting the possibility that each receptor and its cognate ligand may use a different route for cellular signaling. Therefore, the expression of Trk receptors in oculomotor, trochlear, and abducens motoneurons, as well as abducens internuclear neurons, suggests that their associated neurotrophins may exert an influence on the normal operation of the oculomotor circuitry. The presence of multiple Trk receptors on individual cells indicates that they likely act in concert with each other to regulate distinct functions.
Collapse
|
14
|
Morcuende S, Gadd CA, Peters M, Moss A, Harris EA, Sheasby A, Fisher AS, De Felipe C, Mantyh PW, Rupniak NMJ, Giese KP, Hunt SP. Increased neurogenesis and brain-derived neurotrophic factor in neurokinin-1 receptor gene knockout mice. Eur J Neurosci 2003; 18:1828-36. [PMID: 14622216 DOI: 10.1046/j.1460-9568.2003.02911.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
It has previously been shown that chronic treatment with antidepressant drugs increases neurogenesis and levels of brain-derived neurotrophic factor in the hippocampus. These changes have been correlated with changes in learning and long-term potentiation and may contribute to the therapeutic efficacy of antidepressant drug treatment. Recently, antagonists at the neurokinin-1 receptor, the preferred receptor for the neuropeptide substance P, have been shown to have antidepressant activity. Mice with disruption of the neurokinin-1 receptor gene are remarkably similar both behaviourally and neurochemically to mice maintained chronically on antidepressant drugs. We demonstrate here that there is a significant elevation of neurogenesis but not cell survival in the hippocampus of neurokinin-1 receptor knockout mice. Neurogenesis can be increased in wild-type but not neurokinin-1 receptor knockout mice by chronic treatment with antidepressant drugs which preferentially target noradrenergic and serotonergic pathways. Hippocampal levels of brain-derived neurotrophic factor are also two-fold higher in neurokinin-1 receptor knockout mice, whereas cortical levels are similar. Finally, we examined hippocampus-dependent learning and memory but found no clear enhancement in neurokinin-1 receptor knockout mice. These data argue against a simple correlation between increased levels of neurogenesis or brain-derived neurotrophic factor and mnemonic processes in the absence of increased cell survival. They support the hypothesis that increased neurogenesis, perhaps accompanied by higher levels of brain-derived neurotrophic factor, may contribute to the efficacy of antidepressant drug therapy.
Collapse
Affiliation(s)
- Sara Morcuende
- Department of Anatomy and Developmental Biology, Medawar Building, UCL, Gower Street, London WC1E 6BT, UK
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Suzuki R, Morcuende S, Webber M, Hunt SP, Dickenson AH. Superficial NK1-expressing neurons control spinal excitability through activation of descending pathways. Nat Neurosci 2002; 5:1319-26. [PMID: 12402039 DOI: 10.1038/nn966] [Citation(s) in RCA: 311] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2002] [Accepted: 09/04/2002] [Indexed: 11/08/2022]
Abstract
The increase in pain sensitivity that follows injury is regulated by superficially located projection neurons in the dorsal horn of the spinal cord that express the neurokinin-1 (NK1) receptor. After selective ablation of these neurons in rats, we identified changes in receptive field size, mechanical and thermal coding and central sensitization of deeper dorsal horn neurons that are important for both pain sensations and reflexes. We were able to reproduce these changes by pharmacological block of descending serotonergic facilitatory pathways. Using Fos histochemistry, we found changes in the activation of serotonergic neurons in the brainstem as well as evidence for a loss of descending control of spinal excitability. We conclude that NK1-positive spinal projection neurons, activated by primary afferent input, project to higher brain areas that control spinal excitability--and therefore pain sensitivity--primarily through descending pathways from the brainstem.
Collapse
MESH Headings
- Animals
- Brain Stem/cytology
- Brain Stem/drug effects
- Brain Stem/metabolism
- Efferent Pathways/cytology
- Efferent Pathways/drug effects
- Efferent Pathways/metabolism
- Hyperalgesia/metabolism
- Hyperalgesia/physiopathology
- Immunohistochemistry
- Immunotoxins
- Male
- Nerve Fibers, Myelinated/drug effects
- Nerve Fibers, Myelinated/metabolism
- Nerve Fibers, Unmyelinated/drug effects
- Nerve Fibers, Unmyelinated/metabolism
- Neural Inhibition/drug effects
- Neural Inhibition/physiology
- Pain/metabolism
- Pain/physiopathology
- Pain Measurement/drug effects
- Pain Threshold/drug effects
- Pain Threshold/physiology
- Posterior Horn Cells/cytology
- Posterior Horn Cells/drug effects
- Posterior Horn Cells/metabolism
- Proto-Oncogene Proteins c-fos/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Neurokinin-1/drug effects
- Receptors, Neurokinin-1/metabolism
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/metabolism
- Receptors, Serotonin, 5-HT3
- Ribosome Inactivating Proteins, Type 1
- Saporins
- Serotonin Antagonists/pharmacology
- Substance P/analogs & derivatives
- Substance P/metabolism
- Synaptic Transmission/drug effects
- Synaptic Transmission/physiology
Collapse
Affiliation(s)
- Rie Suzuki
- Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, UK.
| | | | | | | | | |
Collapse
|
16
|
Morcuende S, Delgado-Garcia JM, Ugolini G. Neuronal premotor networks involved in eyelid responses: retrograde transneuronal tracing with rabies virus from the orbicularis oculi muscle in the rat. J Neurosci 2002; 22:8808-18. [PMID: 12388587 PMCID: PMC6757699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
Abstract
Retrograde transneuronal tracing with rabies virus from the right orbicularis oculi muscle was used to identify neural networks underlying spontaneous, reflex, and learned blinks. The kinetics of viral transfer was studied at sequential 12 hr intervals between 3 and 5 d after inoculation. Rabies virus immunolabeling was combined with the immunohistochemical detection of choline acetyltransferase expression in brainstem motoneurons or Fluoro-Ruby injections in the rubrospinal tract. Virus uptake involved exclusively orbicularis oculi motoneurons in the dorsolateral division of the facial nucleus. At 3-3.5 d, transneuronal transfer involved premotor interneurons of trigeminal, auditory, and vestibular reflex pathways (in medullary and pontine reticular formation, trigeminal nuclei, periolivary and ventral cochlear nuclei, and medial vestibular nuclei), motor pathways (dorsolateral quadrant of contralateral red nucleus and pararubral area), deep cerebellar nuclei (lateral portion of interpositus nucleus and dorsolateral hump ipsilaterally), limbic relays (parabrachial and Kölliker-Fuse nuclei), and oculomotor structures involved in eye-eyelid coordination (oculomotor nucleus, supraoculomotor area, and interstitial nucleus of Cajal). At 4 d, higher order neurons were revealed in trigeminal, auditory, vestibular, and deep cerebellar nuclei (medial, interpositus, and lateral), oculomotor and visual-related structures (Darkschewitsch, nucleus of the posterior commissure, deep layers of superior colliculus, and pretectal area), lateral hypothalamus, and cerebral cortex (particularly in parietal areas). At 4.5 and 5 d the labeling of higher order neurons occurred in hypothalamus, cerebral cortex, and blink-related areas of cerebellar cortex. These results provide a comprehensive picture of the premotor networks mediating reflex, voluntary, and limbic-related eyelid responses and highlight potential sites of motor learning in eyelid classical conditioning.
Collapse
Affiliation(s)
- Sara Morcuende
- Laboratorio Andaluz de Biologia, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | | | | |
Collapse
|
17
|
Morcuende S, Trigo JA, Delgado-García JM, Gruart A. Harmaline induces different motor effects on facial vs. skeletal-motor systems in alert cats. Neurotox Res 2001; 3:527-35. [PMID: 15111242 DOI: 10.1007/bf03033208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Harmaline's effects on reflex and classically conditioned eyelid responses and on tremor picked up by a coil attached to the back were measured in alert cats. Harmaline at a dose of 10 mg/kg produced skeletal muscle tremogenic effects that lasted 4h. Back movements presented a tremor-like displacement with a frequency peak at 10 Hz, but lid responses oscillated as in controls, at 20 Hz during both reflex and conditioned eyelid movements, with no increase in oscillation amplitude or frequency. The learning curves of harmaline-injected animals remained as in controls, but eyelid conditioned responses showed longer latencies, and smaller amplitude and peak velocity. Reflex and already-learned eyelid responses were not modified by harmaline. These results imply that neuronal control systems for skeletal-motor and facial responses are differentially affected by harmaline.
Collapse
Affiliation(s)
- S Morcuende
- Division de Neurociencias, Laboratorio Andaluz de Biologia, Universidad Pablo de Olavide, Ctra. de Utrera, Km. 1, E41013-Sevilla, Spain
| | | | | | | |
Collapse
|
18
|
Gruart A, Morcuende S, Martínez S, Delgado-García JM. Involvement of cerebral cortical structures in the classical conditioning of eyelid responses in rabbits. Neuroscience 2001; 100:719-30. [PMID: 11036206 DOI: 10.1016/s0306-4522(00)00325-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The classical conditioning of the eyelid motor system in alert behaving rabbits has been used to study the expression of Fos in the hippocampus, and in the occipital, parietal, piriform and temporal cortices. Animals were classically conditioned with both delay and trace conditioning paradigms. As conditioned stimulus, both short and long (20 and 100 ms) tones (600 Hz, 90 dB) or short, weak (20 ms, 1kg/cm(2)) air puffs were used. The unconditioned stimulus was always a long, strong (100 ms, 3 kg/cm(2)) air puff that started 250-270 ms after the onset of the conditioned stimulus. The expression of Fos was significantly increased after both delayed and trace conditioning in the hippocampus, and in the parietal and piriform cortices contralateral to the unconditioned stimulus presentation side, compared with equivalent ipsilateral structures in conditioned animals, or with Fos production in the same contralateral structures in pseudo-conditioned and control animals. Fos expression in some cortical sites was specific to tone versus air puff stimuli when used as conditioned stimulus. Thus, Fos expression was significantly increased in the contralateral temporal lobe when tones were used as conditioned stimulus, for both delayed and trace conditioning paradigms, but not when animals were conditioned to short, weak air puffs. The present results indicate a specific Fos activation in several cerebral cortical structures during associative eyelid conditioning.
Collapse
Affiliation(s)
- A Gruart
- Laboratorio Andaluz de Biología, Universidad Pablo de Olavide, 41013, Sevilla, Spain
| | | | | | | |
Collapse
|