Batrachoidids, which include midshipman and toadfish are less known among embryologists, but are common in other fields. They are characteristic for their acoustic communication, and develop hearing and sound production while young juveniles. They lay large benthic eggs (>5mm) with a thick chorion and adhesive disk and slow development, which are particularly challenging for studying embryology. Here we took advantage of a classical tissue clearing technique and the OPenT open-source platform for optical tomography imaging, to image a series of embryos and larvae from 3 to 30mm in length, which allowed detailed 3D anatomical reconstructions non-destructively. We documented some of the developmental stages (early and late in development) and the anatomy of the delicate stato-acoustic organs, swimming bladder and associated sonic muscles. Compared to other techniques accessible to developmental biology labs, OPenT provided advantages in terms of image quality, cost of operation and data throughput, allowing identification and quantitative morphometrics of organs in larvae, earlier and with higher accuracy than is possible with other imaging techniques.

The research related to hearing loss has caused a major advance in understanding lhe mechanisms that govern the development, function and response to injury and aging af lhe inner car. The purpose af this paper is to deseribe lhe solutions to the problems existing in lhe inoer ear hearing aids, as well as technological advances in research to overcame this problem and develop new more effective hearing implants.

Batrachoidids, which include midshipman and toadfish are less known among embryologists, but are common in other fields. They are characteristic for their acoustic communication, and develop hearing and sound production while young juveniles. They lay large benthic eggs (>5 mm) with a thick chorion and adhesive disk and slow development, which are particularly challenging for studying embryology. Here we took advantage of a classical tissue clearing technique and the OPenT open-source platform for optical tomography imaging, to image a series of embryos and larvae from 3 to 30 mm in length, which allowed detailed 3D anatomical reconstructions non-destructively. We documented some of the developmental stages (early and late in development) and the anatomy of the delicate stato-acoustic organs, swimming bladder and associated sonic muscles. Compared to other techniques accessible to developmental biology labs, OPenT provided advantages in terms of image quality, cost of operation and data throughput, allowing identification and quantitative morphometrics of organs in larvae, earlier and with higher accuracy than is possible with other imaging techniques.

The discovery of a partial cranium at the site of Aroeira (Portugal) dating to 389-436 ka augments the current sample of Middle Pleistocene European crania and makes this specimen penecontemporaneous with the fossils from the geographically close Atapuerca Sima de los Huesos (SH) and Arago sites. A recent study of the cranium documented a unique combination of primitive and derived features. The Aroeira 3 cranium preserves the right temporal bone, including the petrosal portion. Virtual reconstruction of the bony labyrinth from μCT scans provides an opportunity to examine its morphology. A series of standard linear and angular measures of the semicircular canals and cochlea in Aroeira 3 were compared with other fossil hominins and recent humans. Our analysis has revealed the absence of derived Neandertal features in Aroeira 3. In particular, the specimen lacks both the derived canal proportions and the low position of the posterior canal, two of the most diagnostic features of the Neandertal bony labyrinth, and Aroeira 3 is more primitive in these features than the Atapuerca (SH) sample. One potentially derived feature (low shape index of the cochlear basal turn) is shared between Aroeira 3 and the Atapuerca (SH) hominins, but is absent in Neandertals. The results of our study provide new insights into Middle Pleistocene population dynamics close to the origin of the Neandertal clade. In particular, the contrasting inner ear morphology between Aroeira 3 and the Atapuerca (SH) hominins suggests a degree of demographic isolation, despite the close geographic proximity and similar age of these two sites.

INTRODUCTION: Auditory conditioning consists of the pre-exposure to low levels of a potential harmful agent to protect against a subsequent harmful presentation. OBJECTIVE: To confirm if conditioning with an agent different from the used to cause the trauma can also be effective. METHOD: Experimental study with 17 guinea pigs divided as follows: group Som: exposed to 85 dB broadband noise centered at 4 kHz, 30 minutes a day for 10 consecutive days; group Cont: intramuscular administration of gentamicin 160 mg/kg a day for 10 consecutive days; group Expt: conditioned with noise similarly to group Som and, after each noise presentation, received gentamicin similarly to group Cont. The animals were evaluated by distortion product otoacoustic emissions (DPOAEs), brainstem auditory evoked potentials (BAEPs) and scanning electron microscopy. RESULTS: The animals that were conditioned with noise did not show any protective effect compared to the ones that received only the ototoxic gentamicin administration. This lack of protection was observed functionally and morphologically. CONCLUSION: Conditioning with 85 dB broadband noise, 30 min a day for 10 consecutive days does not protect against an ototoxic gentamicin administration of 160 mg/kg a day for 10 consecutive days in the guinea pig.

INTRODUCTION: Electroacoustic stimulation is an excellent option for people with residual hearing in the low frequencies, who obtain insufficient benefit with hearing aids. To be effective, the subject's residual hearing should be preserved during cochlear implant surgery.OBJECTIVES: To evaluate the hearing preservation in patients that underwent implant placement and to compare the results in accordance with the approach to the inner ear.METHODS: 19 subjects underwent a soft surgical technique, and the electrode MED-EL FLEX(tm) EAS, designed to be atraumatic, was used. We evaluated pre- and postoperative tonal audiometric tests with an average of 18.4 months after implantation, to measure the rate of hearing preservation.RESULTS: 17 patients had total or partial preservation of residual hearing; 5 had total hearing preservation and two individuals had no preservation of hearing. The insertion of the electrode occurred through a cochleostomy in 3 patients, and in 2 of these there was no hearing preservation; the other 16 patients experienced electrode insertion through a round window approach. All patients benefited from the cochlear implant, even those who are only using electrical stimulation.CONCLUSION: The hearing preservation occurred in 89.4% of cases. There was no significant difference between the forms of inner ear approach.

Abstract Introduction: The use of electron microscopy in the study of the inner ear has allowed us to observe minute details of the hair cells, especially in ototoxicity studies; however, the preparation of this material is a difficult and delicate task. In an attempt to simplify the handling of these materials, two agents, toluidine blue and ethylenediamine tetra-acetic acid were tested, in addition to the elimination of osmium tetroxide during the preparation of albino guinea pig cochleae. We also tested the applicability of these methodologies in an ototoxicity protocol. Objective: To verify the quality of the images obtained with and without the use of ethylenediamine tetra-acetic acid, toluidine blue and osmium tetroxide in the preparation of cochleae of albino guinea pigs for the scanning electron microscopy. Methods: Three groups of cochleae were used. In Group 1, 10 cochleae were prepared with the usual methodology, dissecting the optical capsule without decalcification and using osmium tetroxide as a post-fixative agent. In Group 2, we prepared 10 cochleae decalcified with ethylenediamine tetra-acetic acid, injecting toluidine blue in the endolymphatic space to facilitate the identification of the organ of Corti. In Group 3, we used 4 cochleae of guinea pigs that received 3 doses of cisplatin (7.5 mg/kg, D1-D5-D6), two prepared according to the methodology used in Group 1 and two with that used in Group 2. Scanning electron microscopy images were obtained from the organ of Corti region of the basal turn of each cochlea. Results: The organ of Corti was more easily identified with the use of toluidine blue. The dissection of the cochlea was more accurate in the decalcified cochleae. The quality of the images and the preservation of the organ of Corti obtained with the two methodologies were similar. Conclusion: The proposed modifications resulted in images of similar quality as those observed using the traditional methodology.

Objetivo: avaliar o efeito da idade sobre o ganho do reflexo vestíbulo-ocular por meio do v-HIT. Métodos: estudo transversal, analítico, observacional, realizado com 90 indivíduos sem alterações otoneurológicas autorrelatadas, que foram submetidos ao exame v-HIT, com o intuito de avaliar o ganho dos canais semicirculares e a velocidade dos impulsos cefálicos. Resultados: a idade da amostra variou de 20 a 83 anos. Optou-se pela divisão em três faixas etárias para facilitar a análise: 18 a 30 anos; 31 a 59 anos e maior que 60 anos. Houve diminuição dos ganhos do reflexo vestíbulo-ocular dos canais semicirculares anterior direito e posteriores com o aumento da idade. As médias do ganho dos canais semicirculares foram próximas a 1 e as velocidades, acima de 100º/s. Conclusão: as médias do ganho dos canais semicirculares estiveram de acordo com os padrões de normalidade da literatura. Apenas os canais semicirculares posteriores e o anterior direito apresentaram redução do ganho com o aumento da idade.