I: History and Research Objectives

The Center of Bioacoustics is an inter-disciplinary joint research-effort between the departments of Audiology and Human Anatomy. The Center was established on October 1999 and it is administered by a council of six members, 4 university professors and 2 experts in biophysics including: Prof. Silvano Capitani director of the Human Anatomy Dept.; Prof. Alessandro Martini director of the Center and of the Dept. of Audiology Prof. Remy? Pujol, director of the laboratory of Neurobiologie de l?Audition ? Plasticitè Synaptique, University of Monpellier; Prof. Daniele Ricci; Silvano Prosser MD and Stavros Hatzopoulos Ph.D.

The main objectives of the center are the envision and creation of new techniques, animal models and experimental methodologies which can be applied to a wide area of Bioacoustics, Pharmacology and Audiology. Analytically:

  • The promotion and the activation of projects aiming the study of molecular and cellular mechanisms, involved in the genesis of diseases related to the hearing apparatus.

  • Identification and characterization of the factors which modulate the proliferation, differentiation and the apoptosis of the cells in the hearing apparatus.

  • Experimental evaluation of the cochlear damages induced by ototoxic agents and noise.

  • Experimentation on therapeutic regimes and on new methodologies/ technologies which can recover the hearing function.

  • Organization of educational initiatives, for the update related to the scientific developments on the physiopathological aspects of the diseases related to hearing.

II: Infrastructure

     The Center or Bioacoustics is organized into two main sub-groups. The first is occupied with the electrophysiological aspects of human and animal hearing (Vivo measurements), while the second studies the molecular biology of sensorial and nervous cells from the inner ear (in Vitro measurements).

      The Electrophysiology group has developed several animal models for the detection of ototoxic effects using mice, rats and guinea-pigs. The group mainly develops methodologies based on the otoacoustic emission responses which are signals originating from the inner ear. By using techniques similar to the sonar technology, the processing of the otoacoustic emission responses provides a valuable and powerful tool to study the effects on the forward and backward sound propagation, from the external ear to the cochlea. Any obstacles in the sound transmission result in an alteration of the recorded otoacoustic emission responses. Within this context, any factor influencing the sound propagation to the cochlea can be monitored successfully. Although the standard emission protocols refer mostly to effects within the auditory periphery, new emission protocols can provide information on the status of the efferent system identifying possible hearing complications in the central nervous system. Verification of the latter is derived by the information obtained from recordings of evoked auditory potentials, which monitor the course of the sound stimuli from the external ear up to the brainstem.

At present, the following objectives are pursued:

(1) the development of experimental procedures which can detect mild to light ototoxic effects or alteration of the hearing function.

(2) the development of solutions by which to reverse / compensate the cochlear damages.

      The Molecular Biology group utilizes a number of models such as: whole cochleas isolated from immature rats, hair cells deriving from the isolated cochleas, primary cultures of neurons from Scarpa?s ganglion cells , and an immortalized cell line (OCK-3 cells) of hair cell precursors. The research objectives are directed towards the elucidation of the mechanisms involved in the cytotoxicity of drugs (gentamicin, cisplatin etc), and in particular on the oxygen radicals (ROS) production or glutathione (GSH) depletion, and control exerted by some signal transducers, as protein kinases C (PKCs). Apoptosis is investigated by electron microscopy, phase contrast or fluorescence microscopy, by vitality assay and by FACS. Protein analysis is lead by immuno-histochemistry and immunochemistry after PAGE and WB. Other substances deriving from phosphoinositide cycle and able to regulate PKC activity are detected by TLC and HPLC.

Developing areas are:

the over-expression of regulatory proteins and their mutants, and the production of non commercial antibodies directed towards cytoskeletal proteins recognized to exert an important role in auditive pathology.

III : Available Instrumentation

1. In vivo-studies:

Animal experimentation can be pursued by using electrophysiological and acoustical state of the art instrumentation. A specially constructed isolation booth permits the recording of responses at very low stimulus levels i.e. 0 dB SPL.

  • Otoacoustic Emissions: Both click and tone stimulation modalities are available. For the latter it is possible to stimulate up to 20 kHz.

  • Evoked Potentials: Click and tone-burst stimulation up to 30 kHz for a variety of stimulation modalities.

2. In Vitro-Studies:

  • Cytofluorimetry
  • TLC
  • HPLC.

3. Multimedia design and INTERNET :

In order to enhance the data distribution for research and educational purposes the center of Bioacoustics is equipped for multimedia design and production (mainly multimedia CD-rom titles using Macromedia?s Director technologies). Additional facilities include a 24 h INTERNET connection using the university network GARR which connects the majority of northern Italian Universities with a network capable of transmission rates of 1.5 mbits /sec.

IV: Research Personnel (in alphabetical order)

  • Bertolaso Lucia BS/MA : post graduate student in Genetics, guest researcher at the Laboratory of Pharmacology of Caroline Dive, Institute of Pharmacology, University of Manchester, Manchester, U.K; guest researcher to Laboratory of Neurobiologie de l?Audition ? Plasticitè Synaptique of Prof. Rémy Pujol, University of Montpellier, France. Experience in cell culture, immuno-histochemistry, protein analysis, cytofluorimetry.

  • Di Stefano Marcella Ph.D. in Neurophysiology and Neurobiology. Experience in live animal recordings (electrocochleography, Auditory Brainstem Responses and Otoacoustic Emissions); electrophysiological intracellular recordings.

  • Hatzopoulos Stavros Ph.D. in Audiological Engineering (inter-disciplinary degree between electrical and biomedical engineering). Experience in biological signal processing, time-frequency analysis and INTERNET related technologies.

  • Parmeggiani Alina BS.

  • Previati Maurizio BS/MA: guest researcher in the lab of R. Irvine at the AFRC in Cambridge, U.K. Experience in protein analysis, cytofluorimetry, TLC, HPLC.

  • Vitali Cristina, BS, MS :

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