Developmental lead exposure causes startle response deficits in XXXX .

@entity26409 @entity3392 @entity10781
Lead ( @entity10781 ) exposure continues to be an important concern for fish populations. Research is required to assess the long-term behavioral effects of low-level concentrations of @entity10781 and the physiological mechanisms that control those behaviors. Newly fertilized @entity3392 embryos (<2h post fertilization; hpf) were exposed to one of three concentrations of lead (as @entity26409 ): 0, 10, or 30 nM until 24 hpf. (1) Response to a mechanosensory stimulus: Individual larvae (168 hpf) were tested for response to a directional, mechanical stimulus. The tap frequency was adjusted to either 1 or 4 taps/s. Startle response was recorded at 1000 fps. Larvae responded in a concentration-dependent pattern for latency to reaction, maximum turn velocity, time to reach V(max) and escape time. With increasing exposure concentrations, a larger number of larvae failed to respond to even the initial tap and, for those that did respond, ceased responding earlier than control larvae. These differences were more pronounced at a frequency of 4 taps/s. (2) Response to a visual stimulus: Fish, exposed as embryos (2-24 hpf) to @entity10781 (0-10  M) were tested as adults under low light conditions (    60  W/m(2)) for visual responses to a rotating black bar. Visual responses were significantly degraded at @entity10781 concentrations of 30 nM. These data suggest that @entity3392 are viable models for short- and long-term sensorimotor deficits induced by acute, low-level developmental @entity10781 exposures.
