1. SLEEP

2. BIOLOGICAL CLOCKS
 Circadian rhythms – daily
cycles of ~ 24 hours
 Pineal gland regulation –
releases melatonin
 Suprachiasmatic Nucleus
(SCN) acts as a biological clock
 Found in the hypothalamus
 Just above the optic chiasm
 Receives info from the retina
 Retinohypothalamic pathway
 GABA released from the
hypothalamus shuts down
arousal systems

3. RETICULAR ACTIVATING SYSTEM
 RAS is responsible for
sleep/wake behavior and
arousal
 Sensory systems  RAS
 Cortex
 Cortex can stimulate RAS
suggesting wakefulness
can be consciously
maintained

4. ANATOMY OF DREAMING
 During REM Sleep
 ACTIVE  INACTIVE
 Reticular formation
 Parietal Cortex
 Thalamus
 Prefrontal Cortex
 Hypothalamus
 Amygdala & Hippocampus
 Visual Cortex

5. SLEEP IN ANIMALS
 Sleep is risky!
 Why is sleep important?
 Adaptation
 Energy conservation
 Predator vs. prey

6. WHAT DOES SLEEP DO FOR US?
 Restoration
and repair, maintaining
homeostasis
 Sleep deprivation studies show poor cognition and
physiological consequences
 MEMORY!!!
 Activation during REM sleep