Hypothalamus/Thalamus [2]

Question 1

Why doesnt the Hypothalamus have certain regions with no BBB?

Answer 1

allow peripheral signals to access HT

release of hormones made in HT and into blood

Question 2

What is a clear landmark for the back of the hypothalamus?

Answer 2

Mamillary bodies

Question 3

Clinical features of absence

• Hz
• Post ictal confusion?
• eyes?

Answer 3

3 Hz: induced by mut in T type Ca2+ channel gene. Thalamic relay neurons fire Ca2+ spikes at DEPOLARIZED resting pot instead of hyperpolarized (during sleep)

• NO postictal confusion
  (wake up, keep doing your thang)
• blank stare

Question 4

Direct/indirect effects on thalamocortical activity

Which hormones are released (and from where) into the thalamus when you are awakening?

Answer 4

Asleep
Slow wave EEG

Awakening

• Cholinergic neurons in reticular activating system → ACh into thalamus
• Noradrenergic neurosn from locus ceruleus → Noradrenaline into thalamus
• Serotonergic neurons from raphe nuclei → 5Ht into thalamus