#169-6170

Attachment Kit Kit de Gamitures Befestigungsmaterial Kabelbevestigingset Guarnizioni da montare Elementos de fijacin

GARANTIA LIMITADA

Se garantiza por un ao nicamente el grupo central (Los accesorios, aditamentos y el consumo de la pila estn excluidos) Si ocurriera alguna avera durante el uso normal, se reparar o sustituir la pieza o el grupo central. Cat Eye Co., Ltd. deber realizar la reparacin. Para devolver el producto, envulvalo cuidadosamente y no olvide incluir el certificado de garanta y las instrucciones para repararlo. Rogamos escribir claramente a mano o a mquina su nombre y direccin. Los gastos de seguro, manipulacin y transporte sern a cargo de la persona que solicite la reparacin.
Direccin para las reparaciones:

#169-6280

Universal Sensor Band Garniture Universelle pour Dtecteur Universal Befestigungsband Universele Sensor klemstrip Guanizione Universale per Sensore Banda del Sensor Universal

#166-5120

Wheel Magnet Aimant pour roue Radmagnet Wielmagneet Magnete ruota Iman de la rueda

#169-6180

Lithium Battery (CR1620) Pile au lithium Lithium-Batterie Lithum Batterij Bateria al Litio Bateria de Litio

OPERATING INSTRUCTIONS

CA T EY E

bracket

rubber pad
screw cap Fig.15 Test (Fig.16) lever Mount main unit. If main display does not show any figures, press either
Use either 1mm- or 2 mm-thick pads if necessary, according to handlebar diameter. Attach the bracket close to the handlebar stem (fig. 15). Slide main unit onto the bracket from front until it clicks into position. To remove, pull it off forward while pushing down the lever. (fig. 16)

A. B. C. D. E. F. G.

Main Display (Speed) Sensor Pulse Symbol Mode Symbol Speed Scale Symbol Auto Mode Symbol Sub-Display (Selected Function) M (Mode) Button

H. I. J. K. 1. 2. 3.

S/S (Start/Stop) Button Set Button Battery Case Cover Contact Bracket Wire Sensor

4. 5. 6. 7. 8. 9. 10.

Sensor Bands-A (S)(L) Sensor Bands-B Magnet Sensor Band Rubber Pad Bracket Rubber Pad (2 pcs.) Wire Securing Tape Sensor Band Screw

OPEN Fig.16 CLOSE

M button or S/S button to release from power saving function. Spin the wheel to check if sensor pulse symbol flashes. If not, adjust relative positions of magnet and sensor following the instructions.

HOW TO REPLACE THE BATTERY

CR1620 /CR1616

MXS ODO DST TM AVS

BUTTON FUNCTION

M button (Fig.1)
Changes the display in the order shown in fig. 1, and data is displayed on the sub-display. *If held over 2 seconds, 12-hour clock appears.
Turn main unit over, remove battery case cover with coin and insert a new lithium battery properly (CR1620 or CR1616) with the (+) pole upward (fig.17), and close the cover securely. * Please make sure to do the All Clear operation after replacing battery, and to set the unit again. Fig.17
MEASURING AND DISPLAY FUNCTIONS
Current Speed 0.0(3.0) - 65 mile/h(27inch) 1 mile/h under31 miles/h This is always displayed on the main display and updated once a second. SPD ODO Total Distance (Odometer) 0.0 - 9999.9 mile 0.1 mile This is continuously measured until battery wears down or all clear operation is done. At 10,000 miles(km), it returns to zero and counting begins anew. Trip Distance 0.00 - 999.99 mile 0.01 mile The trip distance from start to current point is displayed. With Reset operation, it returns to zero. DST TM Elapsed Time 0:00'00" - 9:59'59" 0.003 % Elapsed time is measured from start to current point, in units of hours, minutes and seconds. At 10 hours, it returns to zero and counting begins anew. With Reset operation, it returns to zero. AVS Average Speed 0.0 - 65.0mile/h 0.3 mile/h The average speed from start to current point is displayed within 27 hours 46 minutes 39 seconds (99,999 seconds) or 999.99 miles (km). If either is exceeded, (.E) is displayed and calculation ceases. MXS Maximum Speed 0.0(3.0) - 65 mile/h(27inch) 1 mile/h With Reset operation, it returns to zero and counting begins anew. 12-hour clock time
The current time is displayed by a 12-hour clock. 0:00' - 11:59' 0.003 %

S/S button

Starts and stops the measurement of trip distance and elapsed time. During operation, speed scale symbol flashes. In Auto Function, this button is invalid.

SET Button

ALL CLEAR
This is for setting the wheel circumference and clock time, switching on/ off Auto Function and to clear all present data and any irregularity. When pressed in stop state in each mode, the following can be revised. In ODO mode --------------------- Wheel circumference In mode ----------------------- 12-hour clock In TM, DST or AVS mode ----- On/off the Auto function

Reset Operation: (Fig.2)

Select any mode except ODO, then press M button and S/S button simultaneously. MXS, AVS, DST and TM will become zero. (When done in ODO, registered wheel circumference will be displayed.)
All Clear Operation: (Fig.3)
When M button, S/S and set buttons are pressed simultaneously, all data stored (ODO, speed scale, Wheel circumference and clock time) is erased. All displays illuminate, then mile/h symbol illuminates. This should only be executed after replacing battery or when irregular display occurs due to static electricity, etc. Since all memories are erased, set necessary data again according to "Main Unit Preparation".
AUTO (AUTOMATIC START/STOP) FUNCTION MAIN UNIT PREPARATION
The following must be completed before operating.
This function switches the main unit to start or stop automatically, in which AUTO symbol appears on the screen, and you are free from pressing S/S button each time.

Fig.7 sporkes

(1) How to measure wheel circumference (L) of your bike (Fig.4)
Put a mark on the tire tread and ride the bike one full wheel revolution. Mark the start and the end of the revolution on the ground and then measure the distance between the two marks. This is your actual circumference. Or, the "Selecting Values Cross Reference Table" tells you an approximate circumference according to tire size.
How to switch on/off the Auto Function.
In TM, DST or AVS, this function switches on/off with each press of SET button. When on, AUTO symbol appears. *With this function, it ceases measuring elapsed time during a stop. * 2 seconds may be elapsed if mount the main unit to the bracket with this function on.

POWER SAVING FUNCTION

When main unit is left without receiving any signal for 60-70 minutes continuously, power supply is shut down and main unit will display ( ) only as the figure. By pressing M button or S/S button, or by receiving signal, this function is released.
magnet Fig.8 sensor band B

(2) Setting Speed Scale

Preform all clear operation. All displays will illuminate. Then mile/h alone will be displayed as illustrated in fig.5. Km/h and mile/h are alternately displayed with each press of S/S button. Press M button to set desired speed scale. The display will change as fig. 6.

TROUBLE SHOOTING

The following situations do not indicate malfunction of the cyclocomputer. Check the following before taking to repair. When current speed does not appear, short-circuit the contact on the back with metal. The unit will function normally if the speed display appears. Display response is slow. ----- Is it at a low temperature under 32F(0C)? ----- It returns to normal state when temperature rises. No display. ----- Has the Lithium Battery in the main unit worn out? ----- Replace the Lithium Battery with a new one. Incorrect data appear. ----- Execute "All Clear" operation. Current speed does not appear. ----- Is there anything on the contact of the main unit or of the bracket? ----- Wipe the contact clean. ----- Is the distance between sensor and magnet too far? ----- Are the marking line of the sensor and the center of magnet matched each other? ----- Refer to "Sensor/Magnet Mounting" and re-adjust correctly. ----- Is the wire broken? ----- Replace the Bracket & Sensor part with a new one. Transmission signal loss in damp or wet conditions. ----- Water or condensation may collect between the bracket sensor and the computer causing an interruption in the data transmission. Wipe the contacts with dry cloth. Contacts can also be treated with a water repellent silicon jell from an automotive parts or hardware store. Do not use industrial water repellent; it may damage the bracket. When the S/S button is pressed, the unit doesn't activate or stop. ----- Is the unit in the Auto function? ----- The S/S button doesn't function in the Auto function. *

(3) Setting the wheel circumference (Fig.6)
The standard wheel circumference of 216 cm for 27" wheel is displayed. When using 216 cm without revision, press M button. ODO will be dissensor band A Fig.9 played and 216 cm is set. For revision, press S/S button to increase the number by one. To increase rapidly, hold down the button. When the sensor band B desired number appears, press M button. ODO will be displayed, and rubber pad the desired number is set.

sensor band A parallel

(4) Resetting or changing the wheel circumference
SET button. The stored number will flicker on the sub-display. Revise the number as desired according to the instructions in (3).
Fig.10 Set main unit in ODO with M button, and stop it with S/S button. Press

sensor band A

Setting the clock time (Fig.7)
Press M button over 2 seconds to select , and stop it with S/S button. Then press SET button, and minutes flash. Press S/S button to advance minutes by one. To advance rapidly, hold down the button. Set Fig.11 the time one or two minutes ahead of the current time. Then press M button, and hours will flash. Use S/S button the same way. Press SET button to complete time setting. *When you press the SET button, the undisplayed seconds will turn to zero. For accuracy, set by the radio time signal.
fork sensor markingline of sensor

center of magnet

MOUNTING TO BIKE
The spokes must run correctly through the inside the magnet as in sensor fig.8. magnet Attach the sensor with Sensor Bands-A-B to the right fork. Choose a band that fits the fork diameter (S size for up to 24, L for oversize). 1. Insert the band-B into the slit of the band-A, and put the rubber pad inside of the band-A(fig. 9). Adjust the length in order that the screw-fastening part of the bands are parallel when mounted to the about 2mm Fig.13 fork(fig. 10). *To pull out the band B from band A, tug strongly. 2. Mount the adjusted bands to the fork along with the sensor, by temouter cable porarily tightening the screw(fig. 11). 3. Align the magnet's center and the sensor's marking line(fig. 12), and make sure of 2mm clearance between the magnet and sensor (fig. 13). Then tighten the screw securely. Cut the excess of the band-B with a nipper or the like. wire securing Secure the wire with tape as fig. 14. Wind the wire round the outer tape cable and adjust length. Loosen the wire in the area marked with the arrow so that the wire does not hinder handlebar operation. Fig.14 wire

Fig.12

MAINTENANCE/PRECAUTIONS
Do not leave the main unit exposed to direct sunlight when the unit is not in use. Do not disassemble the main unit, sensor and magnet. Don't pay too much attention to your computer's functions while riding! Keep your eyes on the road and duly consider to traffic safety. Check relative position of sensor and magnet periodically. For cleaning, use neutral detergent on soft cloth, and wipe off later with dry cloth. Do not apply paint thinner, benzine, or alcohol, to avoid damages on the surface. If there is mud, sand or the like clogs between the button and the body, the movement of the button may be disturbed. Softly wash away such objects with water.

SPECIFICATIONS

Applicable Cycle Sizes Applicable Fork Diameter The length of the wire Power Supply Battery Life 130cm - 229cm 11 - 36 (S:11 - 26 L:21 - 36) 70cm Lithium Battery (CR1620/CR1616) x 1 Approx. 3 years(The life of the first factory-loaded battery may be shorter than this period.) Dimension/Weight 1-13/16" x 1-5/8" x 9/16" (46 x 41 x 14 mm) / 0.79 oz (22.5 g) * The specifications and design are subject to change without notice.

Acta Otolaryngol (Stockh) 1998; 118: 86 89
Behavioural Changes in Hamsters with Otoconial Malformations
H. N. P. M. SONDAG,1 H. A. A. DE JONG,1 J. VAN MARLE2 and W. J. OOSTERVELD1
From the 1Vestibular Department, ENT, and 2Department of Electron Microscopy, Academic Medical Center, Uni6ersity of Amsterdam, The Netherlands
Sondag HNPM, de Jong HAA, van Marle J, Oosterveld WJ. Beha6ioural changes in hamsters with otoconial malformations. Acta Otolaryngol (Stockh) 1998; 118: 8689. For a period of 10 months, the perceptivemotor skills of golden hamsters were tested as part of an experiment to investigate vestibular controlled behaviour. We found that four out of 40 hamsters had more difculties with swimming and equilibrium maintenance than the rest of the group. These disturbances either were apparent during the rst months of testing or developed at a later period. In three hamsters the disturbances persisted over time while in one hamster performance in perceptivemotor skills increased. Histological examination with scanning electron microscopy revealed otoconial abnormalities in the saccule and/or the utricle. The otoconia were either malformed or replaced by spherulites. We conclude that the observed behavioural disturbances were caused by a defective peripheral vestibular organ. The results show similarities with data from pathology in other animals as well as in the human inner ear. Key words: scanning electron microscopy, labyrinths, otolith organs, utricle, saccule.
INTRODUCTION The utricle and saccule comprise the otolith organs, which are part of the peripheral vestibular system, and which play a role in posture and movement. The otoconia, crystals of calcite located on the macula of the otolith organs, are necessary for normal vestibular-controlled behaviour such as equilibrium maintenance and swimming behaviour. Disturbances in swimming behaviour have been reported in animals with otoconial defects, such as otoconial malformations or total absence of otoconia (1, 2). Most of these otoconial alterations were found in animals treated with ototoxic agents or genetically mutant animals. However, alterations in the otoconial layer were also reported in the normal guinea-pig (3). Until now nothing was known about otoconial alterations in the golden hamster. As part of an experiment on the effects of hypergravity on vestibular behaviour, the perceptivemotor skills of golden hamsters were tested during 10 months (4, 5). We found that four out of 40 hamsters had behavioural disturbances and otoconial malformations on the utricular and/or saccular otolithic membrane. The structural alterations in the morphology of the otoconia and their consequences to vestibular-controlled behaviour in animals and humans will be discussed in this article. MATERIALS AND METHODS Animals The 40 male hamsters (Mesocricetus auratus, Harlan, Zeist, The Netherlands) were 4 weeks old (mean body weight 47 g) at the start of the experiment. They were housed in acrylate boxes (cm) and food and water were available ad libitum. The day night cycle
1998 Scandinavian University Press. ISSN 0001-6489
was reversed (light on 19:0007:00 h). The hamsters were tested in a laboratory room with dimmed lights. Swimming and balancing on tubes were registered weekly and treadmill activity once every 2 weeks. The experiments were performed in accordance with the Principles of Laboratory Animal Care (NIH publication no. 86-23, revised 1985) and with the recommendations provided in a special licence as required by the Dutch Law on the Use of Animals in Scientic Research. Beha6iour Swimming in a lane. Swimming in a lane (cm, water-depth 25 cm, water temperature 30C) was used to test the animals swimming ability and speed. The hamsters had to swim to the end of the lane where they could climb an escape ladder. One session, preceding the testing days, was used to train the hamsters for 5 min to swim to the ladder. On the testing days, the animals swam three trials. The crossing time for the middle part of the lane (length 100 cm) was measured. Balancing on tubes. The acrylate tubes (length 100 cm, diameter 2 cm), placed 20 cm above ground level, were either xed to standards (xed tube task) or movable, connected by elastic cords which were attached to the standards (mobile tube task). The testing procedure is described in detail in Sondag et al. (5). Each hamster had to cross the tube three times once a week. Treadmill acti6ity. A treadmill was placed in one of the boxes. The treadmill activity of one hamster was recorded daily by means of a cyclocomputer (CC-MT200, Cateye, Osaka, Japan), providing the average speed, the running time and the distance covered in 1 day.

Acta Otolaryngol (Stockh) 118

Otoconial malformations

Histology After 10 months, the hamsters were killed and the temporal bones were dissected. The patches of utricle and saccule were xed in 2.5% gluteraldehyde+0.5% paraformaldehyde in phosphate buffer solution (0.1 M, pH 7.4) for 20 min. After rinsing in distilled water and air-drying, the specimens were mounted on aluminium stubs and coated with gold for electron microscopical scanning (ISI SS40). For crossing times in the swimming tests and crossing times and falling frequency in the tube tests, the mean of three trials per day per animal was calculated. Data from the swimming tests were statistically assessed with repeated analysis of variance (ANOVA) and from the tube tests with repeated ANOVA with body weight as covariates (ANCOVA). The statistical software SPSS PC +5.0 was used for the analysis (signicant at pB 0.05). RESULTS The four hamsters showed normal locomotion, and treadmill activity (ambulation, average speed and time spent on the treadmill) did not differ signicantly from the other 36 hamsters. The results for the remaining 36 hamsters were as follows. Swimming in a lane: Within 4 weeks, all 36 hamsters were able to swim to the other side of the lane. The hamsters swam in a doggy-paddle style using both forelimbs and hindlimbs. Mean swimming speed was 0.22 m/sec (range 0.2 0.26 m/sec). Tube tasks: Within 5 weeks all 36 hamsters managed to walk on both tubes. The mean crossing time for the xed tube was 16.4 sec (range sec) and the mean number of falls was 0.53 falls per crossing (range 0.051.8 falls). For the mobile tube the crossing time was 24 sec (range sec) and the mean number of falls was 1.1 falls per crossing (range 0.12.3 falls). Histology: All 36 hamsters showed normal otoconia on both the utricle and saccule, and no abnormalities were found in the size or shape of the otoconia (Fig. 1). Hamster I showed severe swimming disturbances, as could be seen when circling under water. This hamster often had to be saved from drowning (no mean swimming speed available). Furthermore, when tested on the tubes, this hamster was not able to stand on the tube or walk on the tube. Histological examination of the otoconial layer showed that both saccules were covered with spherulites (Fig. 2) and no otoconia were present. The otoconial layer of the utricles had normal otoconia. Hamster II showed no difference from the control hamsters in swimming and balancing during the rst

Fig. 1. Otoconia on the saccule of hamsters showing normal vestibular functioning.
10 weeks of testing. After this period, this hamster had a decreased swimming ability which was shown by difculty in keeping its head above water level and swimming with a horizontal body position. Furthermore, the swimming speed (mean speed 0.14 m/sec, range 0.070.25 m/sec) was lower for this hamster than for the rest of the group. The ability to keep its balance on the tube also decreased: in 46% of the trials this hamster was unable to stand on the tube. The otoconia of both the saccules and the utricles were malformed (Fig. 3). Hamster III had a decreased swimming ability that was shown by difculty in keeping its head above water level and swimming with a horizontal body position during the whole period of testing. Furthermore, this hamster swam more slowly than the other hamsters (mean speed 0.08 m/sec, range 0.070.2 m/sec). These differences were observed during the whole period of testing. Balancing on the tubes was within range of the rest of the group. The otoconia of the saccules appeared to be malformed (multifaceted, Fig. 4), while the otoconia from the utricle looked normal.
Fig. 2. Apatite spherulites on the saccular otoconial patch of hamster I.
H. N. P. M. Sondag et al.
Fig. 3. Malformed otoconia on the saccular otoconial patch of hamster II.
Fig. 5. Malformed otoconia on the utricular otoconial patch of hamster IV.
Hamster IV showed a decreased swimming ability during week 112, which was observable in circling during swimming, and a decreased swimming speed (mean speed 0.12 m/sec, range 0.09 0.14 m/sec) compared with the control group. Sometimes the hamster had to be saved from drowning. After week 13, the swimming ability of this hamster improved and was not different from the other hamsters during the rest of the experiment. No difculties were found in balancing on the tubes. The otoconia of the saccules and the utricles were malformed (Fig. 5). DISCUSSION Alterations in otoconia morphology seem to lead to disturbances in vestibular behaviour, such as ataxia, head-tilting and disorientation during locomotion, swimming and air-righting (1, 2). Swimming disturbances were found in animals with otoconial malformations or with a total absence of otoconia. These otoconia alterations were caused either by ototoxic agents or by genetic mutations (1, 2, 6). Until now it
Fig. 4. Multifaceted otoconia on the saccular otoconial patch of hamster III.

has been suggested that vestibular function only decreases when the malformations in the otoconial layer are severe enough. For example, Gray et al. (7) found that destruction of more than two of the four otolith organs of mice led to disturbances in swimming behaviour. The data from hamster I suggest that behavioural disturbances may occur even when only two otolith organs are affected by alterations. The spherulites observed on both saccular maculae of this hamster (Fig. 2) resembled those observed in the otolith organs of a patient described by Johnsson et al. (8). This patient had a hereditary congenital deafness and complained about moments of dizziness. Post-mortem study of the otolith organs revealed that the utricles and saccules were covered with apatite spherulites. The same kind of spherulites was also found in some labyrinths of deaf Dalmatian dogs (9). However, in the last study no systematic research into abnormal vestibular behaviour was included. Thus, spherulites are found both in humans and in other species and are most probably the cause of the observed behavioural disturbances. Rouse et al. (9) hypothesized that a disturbed endolymphatic homeostasis causes these otoconial abnormalities. Through phosphatization, the calcite structure of the otoconia is transformed into an apatite structure resulting in spherulites. Animals with either otoconial malformations or multifaceted otoconia in the otolith organs had less severe problems with performance on the vestibular tasks (hamsters II, III and IV). Furthermore, our data indicate that these disturbances in behaviour occurred at an earlier stage of otoconia malformation in the hamster than in mice, rats or guinea-pigs (13). The reason for this higher sensitivity to otoconial alterations in the hamsters might be that the hamster depends more on vestibular information than the other species do, because of its poorly developed visual system. However, we do
not know whether the underlying layers of the otolith organs were malformed, as examination of these layers was not included in our experiment. The multifaceted appearance of the otoconia of hamster III (Fig. 4) was previously described in fetal rodents and chickens (10 12). However, the multifaceted form of the otoconia is normally replaced by smooth otoconia during maturation (11). We suggest that either the multifaceted otoconia in hamster III never matured or they replaced the normal matured otoconia after an inner ear dysfunction. The otoconial malformations found in hamsters II and IV (Figs. 3 and 5) resemble the collapsed otoconia after decalcication, described by Lim (13). Again, a disturbed endolymphatic homeostasis could be one cause of these malformations, as is the case with the development of spherulites. The data from hamster II, which showed behavioural disturbances after week 10, suggest that such otoconia malformations can develop after birth. The behavioural data from hamster IV (behavioural disturbances during the rst 12 weeks) seem to indicate that a young animal with these otoconial malformations can overcome the vestibular decit. Our data conrm the conclusion that normal otoconia are necessary for normal vestibular function. However, disturbances in behaviour that occur because of otoconial malformations are sometimes only found in specic vestibular information-sensitive tasks. The spherulites seem to be a sign of severe vestibular damage in both humans and other animals, resulting in behavioural disturbances in both groups, while the otoconia malformations observed in the other animals seem to present a milder form of vestibular damage. ACKNOWLEDGEMENTS

The authors gratefully acknowledge the Netherlands Organization for Scientic Research (NWO) for funding this project. This research was supported by a grant from the Foundation for Behavioural and Educational Sciences of this organization (575-62-049).
2. Douglas RJ, Clark GM, Erway LC, Hubbard DG, Wright CG. Effects of genetic vestibular defects on behavior related to spatial orientation and emotionality. J Comp Phys Psych 1979; 93: 467 80. 3. Johnsson L-J, Wright CG, Preston RE, Henry PJ. Defects of the otoconial membranes in normal guinea pigs. Acta Otolaryngol (Stockh) 1980; 89: 93 104. 4. Sondag HNPM, de Jong HAA, van Marle J, Oosterveld WJ. Effects of sustained acceleration on the morphological properties of otoconia in hamsters. Acta Otolaryngol (Stockh) 1995; 115: 227 30. 5. Sondag HNPM, de Jong HAA, Oosterveld WJ. Behavioural disturbances in hamsters subjected to hypergravity; adaptation and re-adaptation to increased gravity forces. Acta Otolaryngol (Stockh) 1996; 116: 1927. 6. Huygen PLM, Fischer AJEM, Kuijpers W. The vestibular function in the manganese-decient rat. Acta Otolaryngol (Stockh) 1986; 101: 19 26. 7. Gray LE, Rogers ME, Ostby JS, Kavlock RJ, Ferrell JM. Prenatal dinocap exposure alters swimming behavior in mice due to complete otolith agenesis in the inner ear. Toxicol Appl Pharmacol 1988; 92: 266 73. 8. Johnsson L-G, Rouse RC, Wright, CG, Henry PJ, Hawkins JE. Pathology of neuroepithelial suprastructures of the human inner ear. Am J Otolaryngol 1982; 3: 77 90. 9. Rouse RC, Johnsson L-G, Wright CG, Hawkins JE. Abnormal otoconia and calcication in the labyrinths of deaf Dalmatian dogs. Acta Otolaryngol (Stockh) 1984; 98: 61 71. 10. Ballarino J, Howland HC, Skinner CW, Brothers EB, Bassett W. Studies of otoconia in the developing chick by polarized light microscopy. Am J Anat 1985; 174: 131 44. 11. Mann S, Parker SB, Ross MD, Skanulis AJ, Williams RPJ. The ultrastructure of the calcium carbonate balance organs of the inner ear: An ultrahigh resolution electron microscopy study. Proc R Soc Lond (Biol) 1983; 218: 415 24. 12. Salamat MS, Ross MD, Peacor DR. Otoconial formation in the fetal rat. Ann Otol 1980; 80: 229 38. 13. Lim DJ. Formation and fate of the otoconia: Scanning and transmission electron microscopy. Ann Otol 1973: 82; 23 35. Submitted No6ember 29, 1996; accepted April 2, 1997 Address for correspondence: HNPM Sondag Vestibular Department, ENT Academic Medical Center Meibergdreef 9 NL-1105 AZ Amsterdam The Netherlands Fax: +5669068 E-mail: h.n.sondag@amc.uva.nl

REFERENCES

1. Lim DJ, Erway LC. Inuence of manganese on genetically defective otolith: A behavioral and morphological study. Ann Otol 1984; 83: 56581.