Meeting Abstract

P2.32  Tuesday, Jan. 5  Seasonal Variation in Memory Formation in First-Year Migratory Songbirds as Revealed by Hippocampal CREB Immunoreactivity NEMETH, Z.*; LUO, Y.; OWEN, J. C.; CAO, Z.; MOORE, F. R.; Univ. of Southern Mississippi, Hattiesburg; Univ. of Maryland, Baltimore; Michigan State University, East Lansing; Univ. of Maryland, Baltimore; Univ. of Southern Mississippi, Hattiesburg znemeth05@gmail.com

Given the largely unfamiliar and unpredictable conditions experienced along migratory routes, natural selection should favor cognitive processes that reduce en route risks and uncertainties in migratory birds. These cognitive processes, however, are poorly understood. We used two intercontinental nocturnal migrants, the long-distance migrant Veery (Catharus fuscescens) and the shorter distance migrant Wood Thrush (Hylocichla mustelina), to assess the levels of spatial learning during the first year of songbird migrants, a critical period in constructing their navigational map. To estimate long-term memory formation, we measured immunoreactivity to cAMP response element binding protein (CREB) in hippocampal samples collected at autumn and spring stopover sites and at a breeding site. CREB-responsive transcription in the hippocampus plays a central role in long-term memory formation thus CREB up-regulation could potentially indicate increased learning and memory formation at a given ecological setting. CREB expression overall was lower in the long-distance migrant and showed seasonal low levels during autumn (first) migration whereas high levels during the breeding season. Our findings suggest that young migratory birds may store relatively little spatial information until their global navigational map is fully developed and gain the ability to compensate for displacement. Moreover, the adaptive value of spatial memory may differ in short- and long-distance migrants due to differential time and energetic constraints, which may result in differential cognitive demands.