HC Place cells taxi drivers

enlarged CA1 region

Rat place cells

How was this diagram obtained?

How reliable is it?

rat running in triangular path

McNaughton et al (1996) J Exp Biol 199, 173–185

Colours represent different neurons

recordings separated by 1 hr in home cage

recordings separated by 6 hours of novel environments

The recording environment consisted of a moderately illuminated room, with a raised triangular track located in the middle. The rat’s task was to move continuously in one direction around the track to receive food reinforcement at the mid-point of each side

It all began…

Note this is actually a restrained rat, being gently moved around

400 ms

O'Keefe J, Dostrovsky J. Brain Res. 1971 Nov;34(1):171-5. [on VLE]

Multiple electrodes

O'Keefe &. Recce (1993) Hippocampus 3, 317–330

Use a computer to do spike recognition

Gothard et al (1996) J Neurosci: 16:823-835

LEDs to track head position and direction

Inbuilt FET amplifier, 14 x 4

Freely moving rat

O’Keefe (1976) Experimental neurol 51, 78-109 (1976)

Place unit 202-2. There is a smaller high-frequency displace unit in the background

O’Keefe (1976) Experimental neurol 51, 78-109 (1976)

O'Keefe Conway (1978) Exp. Brain Res. 31,573-590

light, buzzer, fan, white card,

trained to forage in T-maze

O'Keefe &. Recce (1993) Hippocampus 3, 317–330

place cells [2 and 3] firing as rat ran along runway

theta rhythm of EEG

speed of rat

Precession

at end of rhythm at start of rhythm

rats foraging over platform

record CA1 pyramidal cells in theta θ rhythm

Skaggs et al (1996) Hippocampus 6:149-172

Place cells fire out of θ phase

Skaggs et al (1996) Hippocampus 6:149-172

where was rat when θ was max? where was the max firing of this pyramidal cell?

Review Are the CA1 cells firing at random? Are the CA1 neurons firing to

place some other activity motivation?

http://biolpc22.york.ac.uk/750/mem/place_cells.ppt