The HypothalamusBy Alexander Specking and Michael Sova

What and where is it?• The small center of the brain also known as the pleasure and pain center.• This area manages your extreme feelings, such as rage, joy, aggression

and compassion, and your behaviour concerning these emotions.

Functions• It’s mainly responsible for controlling:

– Metabolism– Homeostasis (constant internal environment)– Hunger– Thirst – Emotions – Body temperature regulation– Circadian rhythms– Sleep patterns & levels of consciousness, including fatigue– Blood Pressure

• Also controls pituitary gland by secreting, producing and discharging, hormones. Because of this it has a great deal of control over many body functions.

How does it carry out the functions?

• Carrying out these functions involves coordinating the activity of the autonomic nervous system and the endocrine system, and ultimately influences several important behaviors.

Exercising Study: Barreto (2010)• Study led by Brazilian researchers at the University of

Campinas.• They exercised obese rodents and found that they

demonstrated signals of restored satiety in hypothalamic neurons and less food intake.

• “In obese animals, exercise increased IL-6 and IL-10 protein levels in the hypothalamus, and these molecules were crucial for increasing the sensitivity of the most important hormones, insulin and leptin, which control appetite.”

• Besides burning calories working out also restores sensitivity of neurons which are involved in the maintenance of satiety, feeling full. This sequentially plays a part in reducing food intake and as a result weight loss.

• The way exercise affects ones control of their body weight has only now been understood.

Depression Study (2008)• Chinese investigators from Hefei and Dutch

researchers in Amsterdam.• Used donated postmortem human brain tissue.• Hypothalamus of critical significance for

development of symptoms of depression• Corticotrophin-releasing factor (CRF) cells in PVN

of human hypothalamus central driving force of the stress response & hyperactive in depression.

• Frozen hypothalami of 7 depressed patients and 7 controls obtained.

• From 16 gene products that were studied, 5 were found to show significant changes.

• The molecular changes found may not only explain hyperactivity of CRF cells but may also be potential targets for new therapeutic strategies.

Fear Study: Swanson (2009)• Larry Swanson of University of Southern

California studied brain activity of rats & mice exposed to rival rodents or cats defending their territory.

• New perspective on what part of brain controls fear: hypothalamus, not amygdala.

• Made lesions in hypothalamus resulted in mice that were not afraid of their predators anymore.

• The study replicated findings for male rats that wandered into another male's territory.

• Even when losing vs. other male, the intruders returned.

Possible dysfunctions:

• Some of the physical aspects and causes of Hypothalamic dysfunctions are:– Disordered sleep– Multiple hormonal dysfunctions– Immune dysfunction– Autonomic dysfunction– Altered body temperatures– Head trauma– Tumors– Malnutrition– Infection and swelling