A key component of the circuitry in the medial temporal region is the hippocampal formation, a telencephalic structure composed of two interlocking gyri, the hippocampus proper and the dentate gyrus. The hippocampus is unique in that it appears to mediate information flow between a variety of dif...
A key component of the circuitry in the medial temporal region is the hippocampal formation, a telencephalic structure composed of two interlocking gyri, the hippocampus proper and the dentate gyrus. The hippocampus is unique in that it appears to mediate information flow between a variety of different sensory inputs and the cortex, and one of it's subunits, the dentate gyrus, continually generates new neurons, even in the adult brain.
Disturbances in hippocampal functioning have been linked to a number of pathological conditions whose etiology includes a dementia-like component (i.e. Alzheimer's type dementias, epileptogenic pathologies, polyglutamine pathogenesis, and schizophrenia). A common link between these etiologies is some form of aberrant morphological change that alters hippocampal neuronal circuitry. To date the functional changes incurred following neuronal reorganization are poorly understood and to address this issue we examine both the synaptic physiology of the hippocampal formation and the physiology of neurogenesis (the birth of new neurons) in the adult brain.
Synaptic transmission is one of the ways that neurons communicate with one another, and brief bursts of electrical activity in the brain are believed to alter the strengths of the contacts between neurons, possibly providing a physiological mechanism for information to be processed and stored. We look at how "newly formed" neurons establish and integrate themselves into the existing neural architecture of the adult brain, and how these cells can affect the synaptic physiology of existing tissue. Recently we have discovered that voluntary exercise can increase neurogenesis, learning and synaptic plasticity in the adult brain (1999, PNAS 96:13427-13431). This research has tremendous potential for developing strategies to alleviate pathological brain deterioration, and also provides insight into basic n