Place, space and memory cells

Figure 1. Recording of single neurons in the rodent hippocampal system. (A) A typical laboratory experimental setup for recording spatially sensitive neurons in exploring animals. The animals are implanted with moveable microelectrodes that are situated in the brain region of interest. The electrodes are attached to a tiny drive mechanism that allows the experimenter to advance the electrodes through the brain in small steps of a few tens of microns. The implant can be attached to recording equipment via a headstage (not shown), which stabilizes and boosts the signal and allows it to be transmitted through a long, thin, lightweight cable without loss of signal or gain of electrical noise. Meanwhile, an overhead camera monitors the position of the animal, usually via an LED attached to the headstage. In a typical experiment the animal will forage for food over the surface of the arena while the ongoing activity of the neurons is recorded: sometimes it may perform a navigation task. (B) Schematic of the rat brain, showing the hippocampus and surrounding cortices. (Adapted from Furtak et al. (2007).) Place, space and memory cells