Title

Goal Location Memory in Pigeons: Roles of the Hippocampal Formation and Visual Wulst

Date of Award

2009

Document Type

Dissertation

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Psychology/Experimental

First Advisor

Verner Bingman, Ph.D.

Second Advisor

Rodney Gabel, Ph.D. (Committee Member)

Third Advisor

Patricia Sharp, Ph.D. (Committee Member)

Fourth Advisor

Dale Klopfer, Ph.D. (Committee Member)

Abstract

The abilities of homing pigeons (Columba livia) to navigate through unfamiliar territory and locate goals using visual cues have been well described. Recent recordings from single cells in the pigeon hippocampal formation (HF) also suggested that pigeons represent what happens at particular locations, that the HF is recruited in such representations, and that the right and left sides of HF participate differently in such representations. The present study examined if the hippocampal formation and a connected visual learning area, the Wulst, of homing pigeons were necessary for learning the contents of different goal locations in an open-field, laboratory environment. Results showed that while control animals were able to distinguish between two different goal locations, pigeons with bilateral hippocampal lesions were impaired at goal discrimination, even though feature cues could have been used to distinguish between goal locations. Unilateral HF lesions revealed that the right HF was more important for content learning than left HF. Wulst lesion pigeons also showed impaired content learning during training, but not testing. Of interest, probe data indicated that left HF and the Wulst were involved in associating multiple cues associated with goals, while right HF was not necessary for this type of learning. These results suggest a revised role for avian HF. HF, particularly right HF, serves an important role in memory for the contents of goal locations. Furthermore, the current results are suggestive of a role for avian HF in episodic-like memory, which includes memory for both the spatial and temporal context of events.