A novel model of spontaneous otitis media with effusion (OME) in the Oxgr1 knock-out mouse.

Objective: A novel mouse model with a specific genetic mutation in a G protein coupled receptor (GPCR) encoded by the Oxgr1 gene results in a predisposition to spontaneous otitis media with effusion. As a primary component of interest in OME, mucin expression was examined in this model to assess expression as compared to wild type animals and suitability as a murine model of OME.

Method: Mutant (Oxgr1(-/-)) and wild-type (Oxgr1(+/+)) mice between ages of 2 and 5 months were examined by otoscopy and auditory brainstem response (ABR).

Binaural interaction in human auditory brainstem evoked potentials.

Binaural interaction was examined by recording human auditory brainstem responses to clicks from scalp electrodes. Deviations of binaurally evoked responses from the sum of monaurally evoked potentials were observed during waves IV through VI. Amplitude and latency of the interactions depended on click polarity: condensation clicks produced interactions of larger magnitude and longer latency than did rarefaction clicks.

Patterns of responses of cortical cells to binaural stimulation.

The relationship between stimulus intensity and response latency implies that the relative time of arrival of input to binaurally sensitive loci can vary over a range significantly longer than the interaural delays resulting from the travel time of sound between the ears. To investigate the effect of such potentially long inter-arrival time intervals, responses of binaurally sensitive neurons in auditory cortex of cats were examined over relatively long interaural delays. Two kinds of interaural delay functions were observed.

A quantitative investigation of spine and dendrite development of neurons in visual cortex (area 17) of Macaca nemestrina monkeys.

In a previous Golgi study (Lund et al., '77) which examined the development of the macaque monkey striate cortex (area 17) it was observed that the dendrites of neurons within the visual cortex show a marked increase in the number of spines on their surface during the first eight weeks of postnatal life. The qualitative observation was also made that all neurons then showed a marked decrease in spine numbers by the time the animal was adult.