20 Hz Bursts of Activity in the Cortico-Thalamic Pathway During Attentive Perception

摘要: It is well established that thalamo-cortical fibers of the visual pathway cat send out collaterals to two recurrent loops: inhibitory, via GABAergic interneurons perigeniculate nucleus (PGN) and excitatory, relayed by pyramidal cells layer 6 striate cortex. Both these loops terminate on principal lateral geniculate (LGN). There are data indicating possible role PGN neurons in synchronization rhythmic activity (see Steriade Llinas, 1988 for a review), whereas hypotheses concerning functions cortico-geniculate lack clear experimental support. This should be important view fact cortical axons outnumber all other excitatory inputs LGN (Wilson et al., 1984). One main reasons understanding input may poor responsiveness anaesthetized cats. was demonstrated Livingstone Hubel (1981) who showed further when become active, after recovered from anaesthesia, also their specific responses stimuli were noticeably enhanced. These effects accompanied more vigorous stimulation.