Olfactory adaptation: recordings from the human olfactory epithelium

Purpose Olfactory adaptation is a peripheral (at the epithelium level) or a central (at the brain level) mechanism resulting from repeated or prolonged odorous exposure that can induce a perceptual decrease. The aim of this study was to assess whether a peripheral adaptation occurs when an odor is repeated ten times. Moreover, the specificity of the peripheral adaptation to the nature of the odorant was investigated. Methods Four odorants (eugenol, manzanate, ISO E Super and phenylethanol) were presented using precisely controlled air-dilution olfactometry. They differed in terms of their physicochemical properties. Electrophysiological recordings were made at the level of the olfactory mucosa, the so-called electro-olfactogram (EOG). Thirty-five right-handed participants were recruited. Results Sixty-nine percent of the participants presented at least one EOG, whatever the odor condition. The EOG amplitude did not significantly decrease over 10 repeated exposures to any odorant. The intensity ratings tended to decrease over stimulations for manzanate, PEA, and eugenol. No correlation was found between the mean EOG amplitudes and the mean intensity ratings. However, the presence of EOG amplitude decreases over stimulations for few subjects suggests that peripheral adaptation might exist. Conclusion Overall, our results did not establish a clear peripheral adaptation measured with EOG but indicate the eventuality of such an effect.

Facial rehabilitation with implant-retained nasal prosthesis of acrylic resin: a case report

ABSTRACT The objective of this study was to report a clinical case of facial rehabilitation with an acrylic implant-retained nasal prosthesis after partial rhinectomy resulting from the resection of a basal cell carcinoma in the patient, a 53-year-old Caucasian, normosystemic, professional cowboy. After clinical examination and in possession of computed tomography images, surgery was performed for the placement of conventional dental implants in the premaxillary region (left side). After the surgery, a three-month period of waiting was observed to allow osseointegration of the implants. Later, the nasal prosthesis was prepared, and at the end of treatment, this presented satisfactory peripheral adaptation, retention and esthetics. The patient has returned for follow-up every 6 months, regarding analysis of the prosthesis color, peri-implant health, hygiene, and exchange of the magnets and relays when necessary. The authors concluded that this therapy may be well indicated in patients with partial and total nasal defects, provided that there is correct planning and execution of the surgical, clinical and laboratory phases.

Defining the visual adaptation field for mesopic photometry: Effect of surrounding source position on peripheral adaptation

In CIE 191:2010, the Commission Internationale de l’Eclairage recommends a mesopic photometry system based on peripheral visual tasks. For implementation of the system, the visual adaptation field needs to be defined, taking into account the surrounding luminance effect on the state of adaptation. A series of vision experiments in the mesopic range has been conducted to measure the surrounding luminance effect with respect to the angle between a peripheral task point and a point source. The results show that the surrounding luminance effect at a peripheral task point decreases with increasing angle at a larger slope than existing models, such as the Stiles-Holladay equation, the Commission Internationale de l’Eclairage general disability glare formula and the Stiles–Crawford equation. A new model for the surrounding luminance effect is proposed.