Technische Universität München

The Entrepreneurial University

Functionally, three layers can be distinguished in the brain structure, involved in the basic human behaviour.
  1. The deepest layer - brain stem -  is generally responsible for autonomic, surviving processes such as heart rate, respiration, blood pressure, digesting, and for arousal. The brain stem includes some basic substructures: medulla, pons and thalamus.
  2. The brain stem is surrounded by a second layer - limbic system - responsible for motivation, emotion and memory. The limbic system includes hippocampus, amygdala and hypothalamus.
  3. The third layer - cerebrum - is  functionally responsible for integration of information, co-ordination of movement, analytical and abstractive thinking. The basic elements of cerebrum are cerebral cortex and corpus callosum.
The frontal lobe, a front part of the brain is involved in planning, organizing, problem solving, selective attention, personality and a variety of higher cognitive functions, including behaviour and emotions.

The autonomic nervous system consists of sympathetic and parasympathetic parts. Sympathetic part of the nervous system prepares body to acute stress or to physical activity by increasing heart rate and strength of muscle heart contraction, blood supply to the heart and active muscles, metabolic rate, blood pressure, rate of gas exchange between lungs and blood as well as mental activity and quickness of response. Parasympathetic part controls elementary functions such as digestion, urination, glandular secretion and conservation of energy. Its action, in opposite to  parasympathetic parts, decreases heart rate, constrict coronary vessels and tissues in the lungs.

Communication between nerve cells bases on neurotransmission. Neurotransmitters are chemical compounds able to trigger, amplify and modulate electrical signals sent from one nerve cell to another. The neurotransmitters diffuse across the synaptic cleft to bind receptors which, to large extent, decide on final effect. Neurotransmitters may cause either excitatory or inhibitory post-synaptic potentials. The neurotransmitters are chemical compounds ranging from simple amines (dopamine) and amino acids (gamma amino butyric acid - GABA), to polypeptides (encephalins).  Noradrenaline, dopamine, serotonin and GABA are involved in the control of many emotional and  mental states. Most of the psychoactive drugs work by changing either their metabolism, or receptor sensitivity to these neurotransmitters.