Navegando por Palavras-chave "olfaction"

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    Conditional Deletion of Ric-8b in Olfactory Sensory Neurons Leads to Olfactory Impairment
    (Soc Neuroscience, 2017) Machado, Cleiton F.; Nagai, Maria H.; Lyra, Cassandra S.; Reis-Silva, Thiago M.; Machado, Andre M. [UNIFESP]; Glezer, Isaias [UNIFESP]; Felicio, Luciano F.; Malnic, Bettina
    The olfactory system can discriminate a vast number of odorants. This ability derives from the existence of a large family of odorant receptors expressed in the cilia of the olfactory sensory neurons. Odorant receptors signal through the olfactory-specific G-protein subunit, G alpha olf. Ric-8b, a guanine nucleotide exchange factor, interacts with G alpha olf and can amplify odorant receptor signal transduction in vitro. To explore the function of Ric-8b in vivo, we generated a tissue specific knock-out mouse by crossing OMP-Cre transgenic mice to Ric-8b floxed mice. We found that olfactory-specific Ric-8b knock-out mice of mixed sex do not express the G alpha olf protein in the olfactory epithelium. We also found that in these mice, the mature olfactory sensory neuron layer is reduced, and that olfactory sensory neurons show increased rate of cell death compared with wild-type mice. Finally, behavioral tests showed that the olfactory-specific Ric-8b knock-out mice show an impaired sense of smell, even though their motivation and mobility behaviors remain normal.
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    Olfactory Heterogeneity in LRRK2 Related Parkinsonism
    (Wiley-Blackwell, 2010-12-15) Silveira-Moriyama, Laura; Munhoz, Renato Pupi; Carvalho, Margarete de J.; Raskin, Salmo; Rogaeva, Ekaterina; Aguiar, Patricia de C.; Bressan, Rodrigo A. [UNIFESP]; Felicio, Andre C. [UNIFESP]; Barsottini, Orlando G. P. [UNIFESP]; Andrade, Luiz Augusto Franco de [UNIFESP]; Chien, Hsin F.; Bonifati, Vincenzo; Barbosa, Egberto R.; Teive, Helio A.; Lees, Andrew J.; UCL; Univ Fed Parana; Universidade de São Paulo (USP); Univ Toronto; Hosp Israelita Albert Einstein; Universidade Federal de São Paulo (UNIFESP); Erasmus MC
    LRRK2 mutations can cause familial and sporadic Parkinson's disease (PD) with Lewy-body pathology at post-mortem. Studies of olfaction in LRRK2 are sparse and incongruent. We applied a previously validated translation of the 16 item smell identification test from Sniffin' Sticks (SS-16) to 14 parkinsonian carriers of heterozygous G2019S LRRK2 mutation and compared with 106 PD patients and 118 healthy controls. the mean SS-16 score in LRRK2 was higher than in PD (p < 0.001, 95% CI for beta = -4.7 to -1.7) and lower than in controls (p = 0.007, 95% CI for beta = +0.6 to +3.6). in the LRRK2 group, subjects with low scores had significantly more dyskinesia. They also had younger age of onset, longer disease duration, and reported less frequently a family history of PD, but none of these other differences reached significance. Odor identification is diminished in LRRK2 parkinsonism but not to the same extent as in idiopathic PD. (C) 2010 Movement Disorder Society