Abstract
1. The behavior of a neuron population of the LGN during a reversible retinal blockade achieved by application of high intraocular pressure was investigated in cats prepared with a midpontine pretrigeminal transection. All experiments were carried out in the dark-adapted state.
2. Upon retinal blockade, the postsynaptic component of the population response of the LGN increased in amplitude, while the presynaptic component of the response remained unchanged or showed a small increase in amplitude.
3. In the control animal, the recovery cycle of the postsynaptic component of the geniculate population response did not show a prolonged depressive phase, whereas the depressive phase became apparent during retinal blockade.
4. The after-positivity of the population response of the LGN also became conspicuous during retinal blockade.
5. The excitability of the terminals of the optic tract fibers of the LGN remained unaltered or showed only a small change during retinal blockade.
