BIO: Ultradian and Infradian Rhythms

Question 1

Ultradian

Answer 1

less than one day

Question 2

Infradian

Answer 2

more than one day

Question 3

what are the 5 sleep stages? (with different EEG signatures)

Answer 3

1. Gamma
2. Beta
3. Alpha
4. Theta
5. Delta

Question 4

Gamma:

Answer 4

Alert, learning, problem-solving

Question 5

Beta:

Answer 5

awake and aroused (excited/anxious)

Question 6

Alpha:

Answer 6

awake and relaxed

Question 7

Theta:

Answer 7

light sleep/dreaming/deep meditation

Question 8

Delta:

Answer 8

deep sleep/repair (glymphatic cycle)/dreamless

Question 9

Kleitman (1969)

Answer 9

Basic Rest Activity Cycle (BRAC) 90 mins day or night

Question 10

when was the glymphatic system first described?

Answer 10

2015

Question 11

Cerebrospinal fluid (CSF)

Answer 11

• helps remove waste products from the brain in a convection process
• happens in pulses when we’re awake- but is much faster during sleep
• It’s an ultradian rhythm (c.90 mins) that can be applied to understand Alzheimer’s development and may lead to treatments

Question 12

Role of Oestrogen:

Answer 12

• Oestrogen increases serotonin levels and the number of serotonin receptors.
• it changes the action of endorphins (endogenous opioids) and protects nerves from damage
• can even stimulate nerve growth

Question 13

Role of Progesterone:

Answer 13

• progesterone increases amygdala activation and lowers its activation threshold
• when its processed, one of its by-products binds to the GABA -> a receptor (the opposite of BZ drugs)