Hippocampal activation of immediate early genes Zenk and c-Fos in zebra finches (Taeniopygia guttata) during learning and recall of a spatial memory task.
Zebra finches (Taeniopygia guttata) are able to learn the position of food by orienting on spatial cues in a 'dry water maze'. In the course of spatial learning, the hippocampus shows high expression of the immediate early genes (IEGs) Zenk and c-Fos, indicating high activation of this area during learning. In contrast, the IEG activity is nearly absent if the birds do not have to rely on spatial cues. In the present experiment it was investigated whether hippocampal activation can also be observed if the learned spatial task is recalled. For this purpose, the hippocampal Zenk and c-Fos activation of birds in an early learning stage was compared with that of others having well reached their maximal performance. The results show that the avian hippocampus is also active during recall of a learned spatial task, but the activation is significantly lower than in animals learning actually. As in previous experiments, hippocampal IEG expression showed strong variation not only in the position of the active patches of neurons, but also in size and cell density. The observed difference contributes to the view that immediate early genes may not be indicators of activation alone, but may be due to a combination of activation and plastic changes.
Mayer
Uwe
U
Dept. Behavioural Biology, Bielefeld University, PO Box 100131, 33501 Bielefeld, Germany. uwe.mayer@uni-bielefeld.de
Watanabe
Shigeru
S
Bischof
Hans-Joachim
HJ
D000818:Animals; D003463:Cues; D051766:Early Growth Response Protein 1 / Q000235:genetics*; D005260:Female; D016762:Genes, fos / Q000235:genetics*; D006624:Hippocampus / Q000502:physiology*; D007858:Learning / Q000502:physiology*; D008297:Male; D018782:Maze Learning; D008568:Memory / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology; D015027:Zebrafish
D051766:Early Growth Response Protein 1