PubMed Health⌕ Search

Biomedical subjects

M Abonnenc

Publications and source records attributed to M Abonnenc.

4 recordsLinked to original sources
PubMed1977

Receptor maturation and synaptogenesis in the golden hamster cochlea.

Maturation of hamster cochlea was studied using light and electron microscopy. Critical stages of receptor and neural structure development have been determined. At birth the hamster cochlea shows a pronounced immaturity, but innervation can already be found. 2 or 3 days later, characteristic afferent synapses can be recognized beginning at the inner hair cell level. Similarly, efferent endings first appear on the inner side at the end of the first week. The onset of auditory function must be related to structures depicted at around 10 days, and cochlear maturation is achieved at about 25 days. The sequence of synaptic development in the cochlea is discussed regarding the general morphogenesis of synapses within the nervous system. Some determinations of the timing of peripheral myelination are given. This process begins almost a week before the presumable date of the onset of function.

Age Factors↗
PubMed1975

[Mauration of unitary responses to tonal stimulation in the cochlear nerve of the kitten].

The maturation of single auditory nerve fiber responses to long-duration (500 ms) tone-bursts was studied in kittens at various stages after birth. Spike discharges were examined as a function of three criteria. 10 Latency. Mean value of the "on" peak latency was about 25 ms at 1 to 3 days after birth. It then regressed, reaching 8 to 12 ms at the end of the first week, and 2 to 4 ms at 20 days. 20 Peristimulus histograms (PSTH). Evolution of PSTH revealed the characteristic sequence of unit reactivity to long duration stimuli (i.e. on, rhythmic, and continuous responses). Rhythmic responses is assumed up to now to be related to the immaturity of synaptic junctions below the hair cells. 30 interval histograms. The interspike interval histograms of the discharges showed a similar evolution. A bimodal distribution corresponding to the rhythmic mode of reactivity, appeared at the end of the first week.

Acoustic Stimulation↗