Early-life nutritional stress affects associative learning and spatial memory but not performance on a novel object test

Abstract

Developmental environments can have long-term effects on cognition. Multiple aspects of cognition may be affected by unfavourable conditions during development if underlying neuronal structures are maturing simultaneously. We investigated the effects of nutritional stress at different stages of development on adult associative learning, spatial memory, and behaviours towards a novel object in a songbird. Zebra finches (Taeniopygia guttata) were raised in consistently high or low food conditions until post-hatch day (PHD) 36 (i.e., nutritional independence), where half of the birds from each condition were switched to the other condition until PHD 61. Subjects were then tested as adults with two associative learning tasks, a hippocampus-dependent spatial memory task, and for responses toward a novel object. Surprisingly, low food treatment before independence facilitated spatial associative learning but impaired an aspect of hippocampus-dependent spatial memory. Responses to a novel object were not altered by treatments. This study demonstrates that developmental stress is able to influence learning without simultaneously affecting a measure of personality.