Slide 18

Perigeniculate Cells Form Disynaptic "Loops" with Thalamocortical Cells

Owing to these connections between the PGN and LGNd, the intracellular injection of a depolarizing current pulse into a PGN cell, which makes this cell burst, results in the generation of a "return" or "feedback" barrage of excitatory postsynaptic potentials. This results from the rebound burst firing in thalamocortical neurons induced by the inhibitory potential resulting from activation of the PGN neuron. This simple, disynaptic loop is the basis for the generation of spindle waves.

Bal, T., von Krosigk, M., and McCormick, D.A. (1995) Synaptic and membrane mechanisms underlying synchronized oscillations in the lateral geniculate nucleus in vitro. Journal of Physiology 483.3: 641-663. 

Bal, T., von Krosigk, M., and McCormick, D.A. (1995) Role of the perigeniculate nucleus in the generation of synchronized oscillations in vitro. Journal of Physiology 483.3: 665-685.