The Ramus lab located in Kanbar Hall, studies the neurobiology of learning and memory at the systems level of analysis. Primarily, research in the lab focuses on the Hippocampal Memory System (sometimes called the Medial Temporal Lobe Memory System) and its interactions with the association neocortex. Damage to the Hippocampal memory system results in a severe deficit in the ability to learn new information (anterograde amnesia). While this deficit was once thought to be global, we now know that it is limited to facts and events, or what is called Declarative memory (memory that can be consciously recalled and declared in a statement).
But human patients and animals with damage to their Hippocampal Memory System do not loose memories laid down before the brain damage. In other words, they have a temporally-graded retrograde amnesia in which memories learned a long time before brain damage are relatively preserved, while those memories learned shortly before brain damage are lost.
This means that while the Hippocampal System is critical for the storage and retrieval of long-term memories, it cannot the final storage site. We believe that the Memory System normally interacts with the association neocortex during learning, and that these cortical areas are the ultimate storage sites for memory.
To look for evidence of these interactions, the lab uses two 16-channel recording systems made by Plexon, Inc. to record from as many as 40 neurons at a time from the brains of awake, behaving rats (go to the Plexon website www.plexoninc.com to see some samples of our data!) We currently have two ongoing projects designed to record simultaneously from the Hippocampal Memory System and the orbitofrontal cortex (an association neocortex) of rats performing memory tasks.
A second focus of the lab is to understand the precise role of the hippocampus itself in memory. To do this, we are examining the effects of lesions restricted to the hippocampus or fornix on a variety of memory tasks in rats. One previous project was recently presented at the 2004 Society for Neuroscience meeting in San Diego, California ( PDF » ) and examined how damage to the hippocampus affected spatial and non-spatial alternation memory in rats. This particular project was begun as a part of Psychology 276, Laboratory in Behavioral Neuroscience: Learning and Memory in the Fall, 2000, and was recently completed as a part of independent study and honors research. A current project is examining the role of the hippocampus in episodic memory (what-where-when memory).