Effects of REM Sleep Deprivation on Rat Hippocampal Neurogenesis
Saint Louis University
College of Arts and Sciences
Definition of Neurogenesis – the process by which cells proliferate, survive, and differentiate into
Until recently, this was thought to occur only at birth, for most granule neurons are produced during
the first two postnatal weeks of life.
Recent studies show that neurogenesis does in fact occur in adults and varies according to a variety
Characteristics of REM (Rapid Eye Movement) Sleep
REM Sleep vs. NREM Sleep
Infants spend a greater amount of time in REM sleep than any other age group.
This supports the evidence that REM sleep is directly involved in brain development.
SLEEP AND WAKE
THROUGHOUT HUMAN LIFE
REMS is a highly activated state
PURPOSE AND HYPOTHESIS
This study poses the question, “What is the effect of REM sleep deprivation on neurogenesis in the
hippocampus of infant rats?”
Hypothesis- Neurogenesis will be significantly decreased in the hippocampus of REMS deprived rats
as compared to non-REMS deprived rats.
-4 young rats (22 days old) were implanted with EEG and EMG electrodes, followed by a 7 day recovery
period. Two were used as controls and two were experimental.
-Both groups were:
*placed in cages which rested on a platform shaker
*connected to a automated shaker system
*Subjected to paradigm for seven days
-REM sleep deprivation/non-deprivation began at 29 days old. On day 4, the rats were given 3 injections
providing a total of 75 mg/kg of BrDU. Injections were received 8 hours apart.
The rats then survived another 96 hrs after injection, continuing either REMS deprivation or non-deprivation.
-Brains were then processed for BrDU immunohistochemistry.
- BrDU stained cells were counted using Stereo Investigator software
provides unbiased estimates of areas, volumes and population counts.
CELL COUNTS USING OPTICAL FRACTIONATOR
REMS-deprivation prevents REMS-generated brain activation
Tonic ongoing activation
recorded on the electrocoticograph as low-amplitude fast frequency waveforms
recorded in LGN and visual cortex as ponto-geniculo-occipital (PGO)-waves
Dentate Gyrus of the Hippocampus
Number of New Cells in Dentate
number of cells
treatm ent groups