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Tramonti Fantozzi MP, Lazzarini G, De Cicco V, Briganti A, Argento S, De Cicco D, Barresi M, Cataldo E, Bruschini L, d'Ascanio P, Pirone A, Lenzi C, Vannozzi I, Miragliotta V, Faraguna U, Manzoni D. The path from trigeminal asymmetry to cognitive impairment: a behavioral and molecular study. Sci Rep 2021; 11:4744. [PMID: 33637775 PMCID: PMC7910455 DOI: 10.1038/s41598-021-82265-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 01/15/2021] [Indexed: 01/02/2023] Open
Abstract
Trigeminal input exerts acute and chronic effects on the brain, modulating cognitive functions. Here, new data from humans and animals suggest that these effects are caused by trigeminal influences on the Locus Coeruleus (LC). In humans subjects clenching with masseter asymmetric activity, occlusal correction improved cognition, alongside with reductions in pupil size and anisocoria, proxies of LC activity and asymmetry, respectively. Notably, reductions in pupil size at rest on the hypertonic side predicted cognitive improvements. In adult rats, a distal unilateral section of the trigeminal mandibular branch reduced, on the contralateral side, the expression of c-Fos (brainstem) and BDNF (brainstem, hippocampus, frontal cortex). This counterintuitive finding can be explained by the following model: teeth contact perception loss on the lesioned side results in an increased occlusal effort, which enhances afferent inputs from muscle spindles and posterior periodontal receptors, spared by the distal lesion. Such effort leads to a reduced engagement of the intact side, with a corresponding reduction in the afferent inputs to the LC and in c-Fos and BDNF gene expression. In conclusion, acute effects of malocclusion on performance seem mediated by the LC, which could also contribute to the chronic trophic dysfunction induced by loss of trigeminal input.
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Affiliation(s)
- Maria Paola Tramonti Fantozzi
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Via San Zeno 31, 56127, Pisa, Italy
| | - Giulia Lazzarini
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | - Vincenzo De Cicco
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Via San Zeno 31, 56127, Pisa, Italy
| | - Angela Briganti
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | - Serena Argento
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Via San Zeno 31, 56127, Pisa, Italy
| | - Davide De Cicco
- Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples "Federico II", Naples, Italy
| | - Massimo Barresi
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Via San Zeno 31, 56127, Pisa, Italy
| | | | - Luca Bruschini
- Department of Surgical, Medical, Molecular Pathology and CriticalCare Medicine, University of Pisa, Pisa, Italy
| | - Paola d'Ascanio
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Via San Zeno 31, 56127, Pisa, Italy
| | - Andrea Pirone
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | - Carla Lenzi
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | - Iacopo Vannozzi
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | | | - Ugo Faraguna
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Via San Zeno 31, 56127, Pisa, Italy
- Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Diego Manzoni
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Via San Zeno 31, 56127, Pisa, Italy.
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