Neurons of the avian nucleus magnocellularis transmit phase-locked action potentials of the auditory nerve in a pathway that contributes to sound localization based on interaural timing differences. We studied developmental changes in synaptic transmission that enable the end-bulb synapse to function as a synaptic relay. In chick, although the auditory system begins to function early in embryon...

We compared the toxicokinetics of methylmercury in captive common loon chicks during two time intervals to assess the impact of feather growth on the kinetics of mercury. We also determined the oral bioavailability of methylmercury during these trials to test for age-related changes. The blood concentration-time curves for individuals dosed during feather development (initiated 35 days post hat...

High intensity sound was used to produce localized hair cell damage within the basilar papilla of chicks at three different ages: embryonic day 20, post-hatch day 10 and post-hatch day 30. At each age separate groups of animals were exposed to broadband white noise or pure tones at 500, 1500 or 3000 Hz for 12 h at 125 dB SPL. Chicks were killed 10 days later. Their basilar papillae were then fi...

The use of the visible implant elastomer (VIE) tagging system in zebrafish (Danio rerio) was examined. Two tag orientations (horizontal and vertical) at the dorsal fin base were tested for tag retention, tag fragmentation and whether VIE tags affected growth and survival of juvenile zebrafish (1-4 month post hatch). Six tag locations (abdomen, anal fin base, caudal peduncle, dorsal fin base, pe...

The interrenalchromaffin tissue ratio (IC ratio) in the adrenal gland of Kuttanad ducks was studied during post hatch development in 78 female birds of 13 age groups from day-old to 24 weeks of age at fortnightly intervals. The measurement was read out from the pictures by the use of “ImageJ software”. The proportion of interrenal tissue in the whole gland was least at sixth week of age (1.15:1...

In most organisms, an internal circadian clock coordinates the expression of biological rhythms and enables individuals to anticipate and respond to the seasonally changing environment. There is remarkable conservation of function in the molecular machinery underlying this circadian clock across taxa with 4 canonical proteins interacting to form an autoregulatory feedback loop: CLOCK, CRYPTOCHR...

The invasive red imported fire ant (Solenopsis invicta) has negatively affected a host of taxonomic groups throughout its acquired North American range. Many studies have hypothesized indirect trophic impacts, but few documented those impacts. We evaluated invertebrate abundance as a factor limiting juvenile survival of the endangered Attwater's prairie-chicken (Tympanuchus cupido attwateri), a...

The current study was conducted to evaluate the effect of dietary supplementation with a lyophilized powder made from plums (P) on host protective immune responses against avian coccidiosis, the most economically important parasitic disease of poultry. One-day-old White Leghorn chickens were fed from the time of hatch with a standard diet either without P (control and P 0 groups) or supplemente...