Sensory integration of danger and safety cues may explain the fear of a quiet coyote.

Sensory integration theory predicts natural selection should favour adaptive responses of animals to multiple forms of information, yet empirical tests of this prediction are rare, particularly in free-living mammals. Studying indirect predator cues offers a salient opportunity to inquire about multimodal risk assessment and its potentially interactive effects on prey responses. Here we exposed California ground squirrels from two study sites (that differ in human and domestic dog activity) to acoustic and/or olfactory predator cues to reveal divergent patterns of signal dominance.

Pre-natal amino acid transport inhibition: long term influences on behavior and protein metabolism.

DBA/2J mice were exposed in utero, between days 15-18 of gestation, to either of two enzyme inhibitors, previously shown to decrease blood-brain, large-neutral amino acid transport in adults: L-methionine-RS-sulfoximine and 2-imidazolidone-4-carboxylic acid. The young mice demonstrated persistently altered motor behavior relative to saline controls when 40-42 days old and evidence of differences in the entry and incorporation of 14C-valine in brain at up to 80 days of age. The findings suggest that interference with blood-brain amino acid transport in utero has long term consequences.

Brain cyclic AMP and memory in mice.

A phosphodiesterase inhibitor 4-(3-cyclopentyloxy-4-methoxyphenyl)-2-pyrrolidone (Rolipram, 10 mg/kg IP) administered immediately, but not 3 hr post-training, reversed an amnesia for an inhibitory avoidance response induced by the protein synthesis inhibitor anisomycin. Immediate post-training administration of Rolipram also enhanced retention for a weakly learned avoidance response. Unshocked animals did not show increased test latencies thus ruling out conditioned aversion as an explanation for the enhanced avoidance.