Hypothalamus

Front 1

Magnocellular Neuron

Back 1

Secrete AVP, OXY...

Front 2

Parvicellular Hypophyseotropic Neuron

Back 2

Master regulators of the anterior pituitary gland indirect via the portal system.

Secrete releasing factors:
Pvh (TRH, CRH, Somatostatin)

Arc (GHRH, GnRH, Dopamine)

Front 3

Hypothalamic Projection Neuron

Back 3

...

Front 4

VMH Lesion Syndrome

Back 4

First described as Frohlich's Syndrome/ Babinski Syndrome

Results in obese phenotype.

Front 5

ob/ob mouse

Back 5

Have mutation in LEPTIN

Obese phenotype, infertile, high stress hormone, hyperphagic, etc.

Leptin replacement can normalize phenotype.

Front 6

**Leptin

Back 6

Regulates CNS control of body weight
- decreases food intake
... see slide

Front 7

What is the physiological role of leptin?

Back 7

An anti-obesity hormone vs. a starvation signal

Really not anti-obesity.
Rather, falling leptin is a critical signal of fasting.

Below a critical level it induces an integrated hypothalamic response.

Front 8

** Hypothalamus Anatomy

Back 8

Lies at base of forebrain.
Borders:
- optic chiasm rostrally
- optic tracts and cerebral peduncles laterally
- mammillary bodies caudally

3 Divisions rostral to caudal:
1) Anterior Zone (preoptic area, supraoptic nuclei- SON, paraventricular hypothalamic nuclei- PVH)

2) Tuberal (contains neuroendocrine cells that secrete releasing factors into portal system at the external zone of the median eminence...)

3) Posterior (Integrates autonomic and behavioral response)

3 Divisions medial to lateral:
1) Periventricular Zone
2) Medial Zone
3) Lateral Zone