Repairing the Damaged Septohippocampal System
David S. Olton Johns Hopkins University
Bob Isaacson made many contributions to my professional life, and the research reported here is a logical extension of what I learned in Bob's lab at the University of Michigan 30 years ago. The research uses the experimental strategies of cognitive neuroscience to examine the mnemonic functions of the septohippocampal system. The results of this research led to two important conclusions. First, in young animals that have normal brain function and good memory, inhibition of cholinergic cells in the medial septal area (MSA) reduces the release of acetylcholine in the hippocampus, reduces the power of hippocampal theta, and impairs spatial recent memory. In old animals, which have age-related mnemonic impairments and neuropathological changes in the septohippocampal system, excitation of cholinergic cells in the MSA can enhance the power of hippocampal theta and reduce the magnitude of age-related mnemonic impairments. These conclusions have significant implications both for our understanding of basic functional neuroscience and for the development of interventions to alleviate neurologically induced cognitive impairments.
My experience in Bob's lab provided the basic background for all as pects of this research. The major contribution was the conceptual one, which would probably be described as "cognitive neuroscience" today, but has had many different verbal labels (e.g., physiological psychology, psychobiology). Detailed analyses of mind/brain relations require experi ments with animals because only animals have a true biological brain, and only animals can provide us with direct access to measure and ma