Aging & plasticity
The in vitro hippocampal slice, perhaps the most widely studied mammalian brain preparation, used to examine the neuropharmacology, neurophysiology, and biophysics of learning and memory. Excitatory afferents to the hippocampus converge in the entorhinal cortex, entering the hippocampus as the perforant path, while GABAergic and cholinergic modulatory inputs enter via the fimbria-fornix from the basal forebrain septal nuclei. Granule cells in the dentate gyrus send mossy fiber projections to the apical dendrites of pyramidal cells of CA3. CA3 neurons send efferents out of the hippocampus to cortical and limbic areas, and Schaffer collaterals of CA3 axons terminate on the apical dendrites of CA1. CA1 axons exit the hippocampus via the subicular region. Additional intrinsic and commissural circuitry is not detailed, for brevity.