The role of cerebellum in learned vocal communication in adult songbirds.

Injury, tumors, ischemia, and lesions in the cerebellum show the involvement of this region in human speech. The association of the cerebellum with learned birdsong has only been identified recently. Cerebellar dysfunction in young songbirds causes learning disabilities, but its role in adult songbirds has not been established. The aim of this study was to investigate the role of the deep cerebellar nuclei (DCN) in adult birdsong. We created bilateral excitotoxic lesions in the DCN of adult male zebra finches (Taeniopygia guttata) and recorded their songs for up to 4 months. Using magnetic resonance imaging (MRI) and immunohistochemistry, we validated the lesion efficacy. We found that the song duration significantly increased from 14 weeks post-op; the increase in duration was caused by a greater number of introductory notes as well as a greater number of syllables sung after the introductory notes. On the other hand, the motif duration decreased from 8 weeks after DCN lesions were induced, which was due to faster singing of syllables, not changes in inter-syllable interval length. DCN lesions also caused a decrease in the fundamental frequency of syllables. In summary, we showed that DCN lesions influence the temporal and acoustic features of birdsong. These results suggest that the cerebellum influences singing in adult songbirds.

Association Between Inferior Turbinate Hypertrophy and Extraesophageal Reflux.

Importance: To the authors' knowledge, no prior studies have examined the association between inferior turbinate hypertrophy (ITH) and extraesophageal reflux (EER). If EER were a cause or cofactor of ITH, antireflux treatment can be considered prior to surgical intervention. Objective: To evaluate EER presence and severity in patients with different degrees of ITH. Design, Setting, and Participants: Prospective multicentric cohort study conducted at 3 referral centers treating patients with EER and certified for 24-hour monitoring of oropharyngeal pH. The monitoring was performed between October 2020 and October 2021. A total of 94 adult patients with EER symptoms were recruited, 90 of whom were analyzed. Interventions: Nasal endoscopy was performed to determine the degree of ITH, according to the Camacho classification. Presence and severity of EER were examined using 24-hour monitoring of oropharyngeal pH. Main Outcomes and Measures: Primary outcomes were presence of EER according to RYAN Score, total percentage of time below pH 5.5, and total numbers of EER events below pH 5.5. Results: Of the 90 analyzed patients (median [IQR] age, 46 [33-58] years; 36 [40%] male patients), 41 had a maximum of second-degree ITH (group 1), and 49 patients had at least third-degree ITH (group 2), according to the Camacho classification. On the basis of the RYAN Score, EER was diagnosed more often in group 2 (69.4%) than in group 1 (34.1%; difference, 35.3% [95% CI, 13.5%-56.9%]). Moreover, compared with group 1, group 2 exhibited higher median total percentage of time below pH 5.5 (median [IQR], group 1: 2.1% [0.0%-9.4%], group 2: 11.2% [1.5%-15.8%]; difference, 9.1% [95% CI, 4.1%-11.8%]) and higher median total number of EER events (median [IQR], group 1: 6 [1-14] events, group 2: 14 [4-26] events; difference, 8 [95% CI, 2-15] events). Patients with proven EER demonstrated no difference in the degree of ITH between the right and left nasal cavity (Cohen g, -0.17 [95% CI, -0.50 to 0.30]), or between the anterior and posterior parts of the nasal cavity (Cohen g, -0.21 [95% CI, -0.50 to 0.17]). Conclusions and Relevance: In this cohort study, patients with a higher degree of ITH had more severe EER. A possible association between severe ITH and EER was demonstrated.