Home » Multi-rate ABRs of low-level lead-exposed chicks. by Lisa M Mages-Haskins
Multi-rate ABRs of low-level lead-exposed chicks. Lisa M Mages-Haskins

Multi-rate ABRs of low-level lead-exposed chicks.

Lisa M Mages-Haskins

Published
ISBN : 9780549746362
NOOKstudy eTextbook
70 pages
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The neurotoxin, lead, is prevalent in the United States and can cause damage to structures of the auditory system. Previous studies on leads effects on the auditory system have not been consistent. The purpose of this study was to determine ifMoreThe neurotoxin, lead, is prevalent in the United States and can cause damage to structures of the auditory system. Previous studies on leads effects on the auditory system have not been consistent. The purpose of this study was to determine if low-levels of lead affect the peripheral auditory system in chicks as measured by the ABR. Fertilized white leghorn eggs were injected with lead acetate and were tested on posthatch day 4. Identical non-exposed chicks were also tested. Click and 3 kHz tonepip evoked ABRs were recorded at rates of 10.3/second and 90.3/second for comparisons in threshold and latency values of the first three waves, P1, P2, and P3. There were no differences in latency between the lead-exposed chicks and the non-exposed chicks at either rate for the click-evoked ABR- however, there was a significant difference in latency between the rates. As previously seen in literature, the ABR components had longer latency with increased rate with the most affected being the later components. The tonepip-evoked ABRs showed an interaction between lead and rate for P1 and P3 latencies. P1 latency increased with increasing rate in the non-exposed chicks, as expected, but not in the lead-exposed chicks. P3 latency increased with increasing rate for both groups of chicks, with a larger increase in latency in the non-exposed group. P2 latency showed a decrease in latency with lead exposure, with no lead-by-rate interaction. When ABR threshold was analyzed, there were no significant differences between the groups of chicks or rates. Thresholds were lower for the tonepips than for the clicks, likely explained by the spectra of the two signals. The results indicate that, although the auditory system as measured by the ABR is not affected by low-level lead exposure, more central parts may be affected and further investigation is recommended.