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https://hdl.handle.net/10216/128937| Author(s): | Joana Margarida Tavares Coelho |
| Title: | Effects of aging on the cholinergic innervation of the rat ventral tegmental area: a stereological study |
| Issue Date: | 2020-05-13 |
| Abstract: | Dopamine neurons in the ventral tegmental area (VTA) play a main role in processing both rewarding and aversive stimuli, and their response to salient stimuli is significantly shaped by afferents originating in the brainstem cholinergic nuclei. Aging is associated with a decline in dopaminergic activity and reduced response to positive reinforcement. We have used stereological techniques to examine, in adult and aged rats, the dopaminergic neurons and the cholinergic innervation of the VTA, and the cholinergic populations of the pedunculopontine tegmental (PPT) and laterodorsal tegmental (LDT) nuclei, which are the only source of cholinergic inputs to the VTA. In the VTA, there were no age-related variations in the number and size of tyrosine hydroxylase (TH)-immunoreactive neurons, but the density of cholinergic varicosities was reduced in aged rats. The total number of choline acetyltransferase (ChAT)-immunoreactive neurons in the PPT and LDT were unchanged, but their somas were hypertrophied in aged rats. Our results suggest that dysfunction of the cholinergic system might contribute for the age-associated deterioration of the brain reward system. |
| Description: | Os neurónios dopaminérgicos da área tegmentar ventral (VTA) desempenham um papel fundamental no processamento de estímulos recompensadores e aversivos, e a sua resposta a estímulos relevantes é modelada de modo significativo por aferentes que têm origem nos núcleos colinérgicos do tronco cerebral. O envelhecimento está associado a um declínio na actividade dopaminérgica e a uma resposta reduzida ao reforço positivo. Neste estudo foram usadas técnicas estereológicas para analisar, em ratos adultos e velhos, os neurónios dopaminérgicos e a inervação colinérgica da VTA, e as populações colinérgicas dos núcleos pedunculopontino (PPT) e tegmentar laterodorsal (LDT), as quais constituem a única fonte da inervação colinérgica da VTA. Na VTA, não houve variações relacionadas com a idade no número e no volume dos neurónios imunorreactivos para a tirosina hidroxilase (TH), mas a densidade das varicosidades colinérgicas estava reduzida nos ratos velhos. O número total de neurónios imunorreactivos para a colina acetiltransférase (ChAT) no PPT e no LDT permaneceu inalterado, mas o volume somático desses neurónios estava aumentado nos ratos velhos. Estes resultados sugerem que a disfunção do sistema colinérgico pode contribuir para a deterioração associada à idade do sistema de recompensa cerebral. |
| Subject: | Medicina básica Basic medicine |
| Scientific areas: | Ciências médicas e da saúde::Medicina básica Medical and Health sciences::Basic medicine |
| DOI: | 10.34626/vene-rk05 |
| TID identifier: | 202613933 |
| URI: | https://hdl.handle.net/10216/128937 |
| Document Type: | Dissertação |
| Rights: | restrictedAccess |
| License: | https://creativecommons.org/licenses/by-nc-nd/4.0/ |
| Appears in Collections: | FMUP - Dissertação |
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|---|---|---|---|---|
| 414338.pdf Restricted Access | Effects of aging on the cholinergic innervation of the rat ventral tegmental area: a stereological study | 2.17 MB | Adobe PDF | View/Open |
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