Simultaneous hypertrophy of cells related to each eye in the lateral geniculate nucleus of the infant monkey following short-term reverse suture.

Three infant monkeys were monocularly deprived from birth and reverse sutured at 3 weeks of age for a further period of 1, 2 or 5 weeks before perfusion. Cell areas were measured in the lateral geniculate nuclei and compared to those in normal monkeys and in monkeys following monocular closure. One week after reverse suture, cells in the initially deprived parvocellular laminae were 17% larger than normal and those in the initially undeprived laminae were 28% larger than normal. The initially undeprived parvocellular cells then shrank back to 14% larger than normal at 2 and 5 weeks while the initially deprived cells also remained hypertrophied. Following reverse suture at 3 weeks of age cells in parvocellular LGN laminae related to both eyes are simultaneously hypertrophied until at least 8 weeks of age and the LGN is therefore markedly abnormal even though the size difference between initially deprived and undeprived cells has been cancelled.